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OBJECTIVE: New transapical minimally invasive artificial chordae implantation devices are a promising alternative to traditional open-heart repair, with the potential for decreased postoperative morbidity and reduced recovery time. However, these devices can place increased stress on the artificial chordae. We designed an artificial papillary muscle to alleviate artificial chordae stresses and thus increase repair durability. METHODS: The artificial papillary muscle device is a narrow elastic column with an inner core that can be implanted during the minimally invasive transapical procedure via the same ventricular incision site. The device was 3-dimensionally printed in biocompatible silicone for this study. To test efficacy, porcine mitral valves (n = 6) were mounted in a heart simulator, and isolated regurgitation was induced. Each valve was repaired with a polytetrafluoroethylene suture with apical anchoring followed by artificial papillary muscle anchoring. In each case, a high-resolution Fiber Bragg Grating sensor recorded forces on the suture. RESULTS: Hemodynamic data confirmed that both repairs—with and without the artificial papillary muscle device—were successful in eliminating mitral regurgitation. Both the peak artificial chordae force and the rate of change of force at the onset of systole were significantly lower with the device compared with apical anchoring without the device (P < .001 and P < .001, respectively). CONCLUSIONS: Our novel artificial papillary muscle could integrate with minimally invasive repairs to shorten the artificial chordae and behave as an elastic damper, thus reducing sharp increases in force. With our device, we have the potential to improve the durability of off-pump transapical mitral valve repair procedures.

Background: Functional mitral regurgitation (FMR) is caused by left ventricular (LV) remodeling and subsequent tethering of the mitral valve (MV). If LV remodeling is irreversibly advanced, it could not be attenuated by the MV procedure alone, although the additional subvalvular procedure could induce LV reverse remodeling by forcibly reducing MV tethering. This study aimed to assess the anti-tethering effect of papillary muscle tugging approximation (PMTA) on LV reverse remodeling after mitral valve replacement (MVR) for non-ischemic FMR. Methods: The study subjects were 19 patients who underwent MVR with and without PMTA [MVR + PMTA (n = 11) and MVR alone (n = 8), respectively] for non-ischemic FMR. The tethering distance (TD) and LV end-systolic volume (ESV) at the preoperative, postoperative, and follow-up periods were assessed in terms of their correlation and time-dependent changes. The intra-LV energy efficiency was also evaluated through vector flow mapping analysis. Results: TD and ESV were comparable between both procedures preoperatively and did not change after MVR alone. In MVR + PMTA, however, a significant decrease was identified in TD and ESV at the early postoperative and follow-up periods, respectively [TD = 48, 30, and 31 mm (p < 0.001) and ESV = 159, 133, and 82 mL (p < 0.001) at the preoperative, postoperative, and follow-up periods, respectively]. Finally, at follow-up, the extent of change from the preoperative value in ESV significantly correlated with that in TD (rho = 0.81, p < 0.001 for overall; rho = 0.93, p < 0.001 for MVR + PMTA; rho = 0.86, p = 0.011 for MVR alone). The ratio of TD to ESV was also significantly correlated with systolic energy loss to LV stroke work after MVR + PMTA (rho = 0.81, p = 0.015). Conclusions: PMTA for non-ischemic FMR could induce LV reverse remodeling depending on the extent of postoperative TD reduction. A smaller TD to ESV was associated with a higher intra-LV energy efficiency after PMTA + MVR. (C) 2021 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

IntroductionMitral valve (MV) prolapse (MVP) is a primary valvular abnormality. We hypothesized that additionally there are concomitant abnormalities of the left ventricle (LV) and MV apparatus in this entity even in the absence of significant mitral regurgitation (MR).ObjectiveTo characterize MV and LV anatomic and functional features in MVP with preserved LV ejection fraction, with and without significant MR, using cardiovascular magnetic resonance (CMR).MethodsConsecutive MVP patients (n = 80, mean 52 years, 37% males) with preserved LV ejection fraction, and 44 controls (46 years, 52% males) by CMR were included, as well as 13 additional patients with “borderline” MVP. From cine images we quantified LV volumes, MV and LV anatomic measurements (including angle between diastolic and systolic annular planes, annular displacement, and basal inferolateral hypertrophy) and, using feature tracking, longitudinal and circumferential peak systolic strains.ResultsSignificant MR was found in 46 (56%) MVP patients. Compared with controls, MVP patients had LV enlargement, basal inferolateral hypertrophy, higher posterior annular excursion, and reduced shortening of the papillary muscles. LV basal strains were significantly increased, particularly in several basal segments. These differences remained significant in patients without significant MR, and many persisted in “borderline” MVP.ConclusionsIn patients with MVP and preserved LV ejection fraction there is LV dilatation, basal inferolateral hypertrophy, exaggerated posterior annular displacement and increased basal deformation, even in the absence of significant MR or overt MVP. These findings suggest that MVP is a disease not only of the MV but also of the adjacent myocardium.

Background Patients with both double orifice mitral valve (DOMV) and bicuspid aortic valve (BAV) malformation are rare. Although DOMV or BAV can be detected in some genetic syndromes, it has not been reported to simultaneously appear in Turner syndrome (TS). TrueVue, TouchVue, and TrueVue Glass are the latest technologies in advanced three-dimensional echocardiography (3DE), which is an important information supplement to two-dimensional echocardiography (2DE) for the diagnosis of congenital cardiac malformations. Herein we report the novel use of the above-mentioned technologies in the diagnosis and evaluation of a rare, combined valve malformation. Meanwhile, we also reviewed the literature for cases involving both DOMV and BAV and their association with various genetic syndromes. Case presentation We present the case of a 5-year-old girl diagnosed with TS because of a developmental delay. DOMV and BAV were found through echocardiographic examination. Three-dimensional transthoracic echocardiography as well as a series of novel advanced techniques were applied to clearly display the spatial structure of all tiers of the mitral valve apparatus, aortic valve, and arch to facilitate an accurate diagnosis. Conclusions This is the first case in which both DOMV and BAV were associated with TS. Innovative TrueVue and TrueVue Glass offer unprecedented photographic stereoscopic images, while TouchVue technology greatly improved the ultrasonic diagnostic workflow and the diagnostic performance of rare valve malformations by adding virtual light sources to display realistic light-shadow effects.

Aims Mitral valve prolapse (MVP) causes left ventricular (LV) remodelling even in the absence of significant mitral regurgitation. To evaluate whether apical insertion of the papillary muscle (PM) influences the pattern and severity of MVP-related LV remodelling. Methods and results All MVP patients who underwent CMR at our institution between December 2008 and December 2019 were included, thoroughly reviewed and grouped according to apical/non-apical PM insertion. Apical PM insertion was found in 53/92 patients (58%) and associated with mitral leaflet thickening (P 5%) and non-sustained ventricular tachyarrhythmias was found in patients with apical PM insertion: 53% vs. 25% (P = 0.04) and 38% vs. 18% (P = 0.04), respectively. Conclusion Apical PM insertion is part of the phenotypic spectrum of MVP, impacts significantly LV remodelling, and potentially may be related to increased ventricular arrhythmogenicity.

Background With an increased number of surgical procedures involving the mitral annular region, the risk of mitral valve prolapse (MVP) has also increased. Previous studies have reported that worsening of MVP occurred early after radiofrequency catheter ablation (RFCA) at papillary muscles in ventricular tachycardia (VT) patients with preoperative MVP. Case summary We report a case where MVP and papillary muscle rupture occurred 2 wk after RFCA in a papillary muscle originated VT patient without mitral valve regurgitation or prolapse before. The patient then underwent mitral valve replacement with no premature ventricular contraction or VT. During the surgery, a papillary muscle rupture was identified. Pathological examination showed necrosis of the papillary muscle. The patient recovered after mitral valve replacement. Conclusion Too many ablation procedures and energy should be avoided.

Force enhancement is one kind of myogenic spontaneous fasciculation in lengthening preload striated muscles. In cardiac muscle, the role of this biomechanical event is not well established. The physiological passive property is an essential part for maintaining normal diastole in the heart. In excessive preload heart, force enhancement relative erratic passive properties may cause muscle decompensating, implicate in the development of diastolic dysfunction. In this study, the force enhancement occurrence in mouse cardiac papillary muscle was evaluated by a microstepping stretch method. The intracellular Ca2+ redistribution during occurrence of force enhancement was monitored in real-time by a Flou-3 (2 mM) indicator. The force enhancement amplitude, the enhancement of the prolongation time, and the tension–time integral were analyzed by myography. The results indicated that the force enhancement occurred immediately after active stretching and was rapidly enhanced during sustained static stretch. The presence of the force and the increase in the amplitude synchronized with the acquisition and immediate transfer of Ca2+ to adjacent fibres. In highly preloaded fibres, the enhancement exceeded the maximum passive tension (from 4.49 ± 0.43 N/mm2 to 6.20 ± 0.51 N/mm2). The occurrence of force enhancement were unstable in each static stretch. The increased enhancement amplitude combined with the reduced prolongation time to induce a reduction in the tension–time integral. We concluded that intracellular Ca2+-synchronized force enhancement is one kind of interruption event in excessive preload cardiac muscle. During the cardiac muscle in its passive relaxation period, the occurrence of this interruption affected the rhythmic stability of the cardiac relaxation cycle.

Background Whether it is possible to perform morphological evaluation of functional tricuspid regurgitation (FTR) on contrast-enhanced computed tomography (CT) was examined by evaluating the relationships between the parameters measured on contrast-enhanced CT and TR severity on transthoracic echocardiography. Methods Fifty patients underwent contrast-enhanced CT. Tricuspid annulus area (TAA), tricuspid annulus circumference (TAC), right ventricular volume (RVV), and the distances between the tips and bases of the papillary muscles were measured on contrast-enhanced CT in diastole and systole. The 50 cases were divided into 34 in the TR ≤ mild group (no TR: 3 cases, trivial TR: 24 cases, mild TR: 7 cases), and 16 in the TR ≥ moderate group (moderate TR: 8 cases, severe TR: 8 cases) using the TR grade measured by transthoracic echocardiography, and then differences between the groups were examined. Results Significant differences were found in TAA, TAC, and RVV (p p 0.7, and the maximum AUC was 0.925 for dRVV. Conclusions TAA, TAC, RVV, and the distance between the tips of the anterior and posterior papillary muscles measured on contrast-enhanced CT were shown to be significantly increased in the TR ≥ moderate group. Detailed morphological assessment of FTR is possible by contrast-enhanced CT.

Background. Mitral valve disease surgery is an evolving field with multiple possible interventions. There is an increasing body of evidence regarding the optimal strategy in secondary mitral regurgitation where the pathology lies within the ventricle. We conducted a systematic review to identify the benefits and limitations of each surgical option. Methods. A systematic review of the literature was performed to identify pertinent randomized controlled trials (RCTs), propensity-matched observational series, and meta-analyses which were considered initially and followed by unmatched observational series using the MEDLINE, Ovid EMBASE, and Cochrane Library. Results. We identified 6 different strategies for treating secondary mitral valve regurgitation: mitral valve replacement, restrictive mitral annuloplasty, surgical revascularization (with and without mitral annuloplasty), subvalvular procedures (papillary muscle approximation, papillary muscle relocation, ring and string procedure), and procedures directly targeting the mitral valve (edge-to-edge repair and anterior leaflet enlargement) alongside transcatheter heart valve therapy. We also highlighted the role of left ventricular assist devices in the management of this condition. The benefits and limitations of each intervention are highlighted. Conclusion. There is currently no unanimous and shared strategy for the optimal treatment of patients with secondary IMR. The management of patients with secondary mitral regurgitation must be entrusted to a multidisciplinary Heart Team to ensure ideal intervention and patient matching for the best outcomes.

Objective The objective of this study was to assess papillary muscle (PM) and mitral valve (MV) structure and function in children and young adults with mild and moderate hypertrophic cardiomyopathy (HCM) using real-time three-dimensional echocardiography (3DE) and to correlate them with HCM related adverse outcomes. Methods Transthoracic research 3DE was performed in HCM patients and controls matched for age and gender. Anterolateral and posteromedial PM mass, apical displacement of anterolateral PM, and left ventricular (LV) mass were measured and indexed to body surface area. The MV annulus and leaflet structure and function were analyzed. Individual PMs were manually planimetered by tracing the endocardial borders on each mid systole frame, taking care to distinguish PMs as distinct from the LV wall. Apical PM displacement was expressed as ratio of the distance between the apex and the base of the anterolateral PM to the entire length of the LV lateral wall (APL index). All 3DE measurements were correlated to adverse outcomes. Results Forty subjects were studied, including 20 HCM patients (age 18.1 ± 9.6 years, 16 male and 4 female), and 20 controls (18.2 ± 9.6 years, 16 male and 4 female). The indexed LV mass in HCM was 74.8 ± 25.8 g/m2 compared to 50.8 ± 12.4 g/m2 in controls (p = 0.001). The anterolateral, posteromedial and combined PM mass were 3.1 ± 2.2 g/m2, 1.7 ± 1.2 g/m2 and 4.9 ± 2.7 g/m2 in HCM, in contrast to respective measurements of 1.1 ± 0.6 g/m2, 1.2 ± 0.6 g/m2 and 2.3 ± 0.8 g/m2 in controls (p Conclusion It is feasible to evaluate PM muscles and MV annulus geometry in children and young adults with HCM using 3DE. The morphologic and functional changes of anterolateral PM may occur in the absence of MV annulus changes. Prospective validation will be required to determine if LV lateral wall length and LV mass may be used as predictors of adverse events.

Cannabis use is associated with known cardiovascular side effects such as cardiac arrhythmias or even sudden cardiac death. The mechanisms behind these adverse effects are unknown. The aim of the present work was to study the cellular cardiac electrophysiological effects of cannabidiol (CBD) on action potentials and several transmembrane potassium currents, such as the rapid (IKr) and slow (IKs) delayed rectifier, the transient outward (Ito) and inward rectifier (IK1) potassium currents in rabbit and dog cardiac preparations. CBD increased action potential duration (APD) significantly in both rabbit (from 211.7 ± 11.2. to 224.6 ± 11.4 ms, n = 8) and dog (from 215.2 ± 9.0 to 231.7 ± 4.7 ms, n = 6) ventricular papillary muscle at 5 µM concentration. CBD decreased IKr, IKs and Ito (only in dog) significantly with corresponding estimated EC50 values of 4.9, 3.1 and 5 µM, respectively, without changing IK1. Although the EC50 value of CBD was found to be higher than literary Cmax values after CBD smoking and oral intake, our results raise the possibility that potassium channel inhibition by lengthening cardiac repolarization might have a role in the possible proarrhythmic side effects of cannabinoids in situations where CBD metabolism and/or the repolarization reserve is impaired.

Objective Mitral valve regurgitation (MR) is a common valvular heart disease where improper closing causes leakage. Currently, no transcatheter mitral valve device is commercially available. Raanani (co-author) and colleagues have previously proposed a unique rotational implantation, ensuring anchoring by metallic arms that pull the chordae tendineae. This technique is now being implemented in a novel device design. The aim of this study is to quantify the rotational implantation effect on the mitral annulus kinematics and on the stresses in the chordae and papillary muscles. Methods Finite element analysis of the rotational step of the implantation in a whole heart model is employed to compare 5 arm designs with varying diameters (25.9 mm to 32.4 mm) and rotation angles (up to 140°). The arm rotation that grabs the chordae was modeled when the valve was in systolic configuration. Results An increase in the rotation angle results in reduced mitral annulus perimeters. Larger rotation angles led to higher chordae stresses with the 29.8 mm experiencing the maximum stresses. The calculated chordae stresses suggest that arm diameter should be Conclusions The upper limit of this diameter range is preferred in order to reduce the stresses in the papillary muscles while grabbing more chords. The findings of this study can help improving the design and performance of this unique device and procedural technique.

The goal of this study was to test whether ischemia-mediated contractile dysfunction underlying the mitral valve affects functional mitral regurgitation (FMR) and the prognostic impact of FMR.FMR results from left ventricular (LV) remodeling, which can stem from myocardial tissue alterations. Stress cardiac magnetic resonance can assess ischemia and infarction in the left ventricle and papillary muscles; relative impact on FMR is uncertain.Vasodilator stress cardiac magnetic resonance was performed in patients with known or suspected coronary artery disease at 7 sites. Images were centrally analyzed for MR etiology/severity, mitral apparatus remodeling, and papillary ischemia.A total of 8,631 patients (mean age 60.0 ± 14.1 years; 55% male) were studied. FMR was present in 27%, among whom 16% (n = 372) had advanced (moderate or severe) FMR. Patients with ischemia localized to subpapillary regions were more likely to have advanced FMR (p = 0.003); those with ischemia localized to other areas were not (p = 0.17). Ischemic/dysfunctional subpapillary myocardium (odds ratio: 1.24/10% subpapillary myocardium; confidence interval: 1.17 to 1.31; p 0.001) was associated with advanced FMR controlling for infarction. Among a subgroup with (n = 372) and without (n = 744) advanced FMR matched (1:2) on infarct size/distribution, patients with advanced FMR had increased adverse mitral apparatus remodeling, paralleled by greater ischemic/dysfunctional subpapillary myocardium (p 0.001). Although posteromedial papillary ischemia was more common with advanced FMR (p = 0.006), subpapillary ischemia with dysfunction remained associated (p 0.001), adjusting for posteromedial papillary ischemia (p = 0.074). During follow-up (median 5.1 years), 1,473 deaths occurred in the overall cohort; advanced FMR conferred increased mortality risk (hazard ratio: 1.52; 95% confidence interval: 1.25 to 1.86; p 0.001) controlling for left ventricular ejection fraction, infarction, and ischemia.Ischemic and dysfunctional subpapillary myocardium provides a substrate for FMR, which predicts mortality independent of key mechanistic substrates.

Infective endocarditis is a serious, potentially life-threatening condition. The valve leaflets and annulus are the most commonly affected sites, but involvement of the papillary muscles is extremely rare. We present the case of a 69-year-old woman who had infective endocarditis only involving the papillary muscle on 18F-FDG PET/CT.

Introduction Catastrophic antiphospholipid syndrome (CAPS) is a rare and serious phenomenon that requires prompt recognition and treatment. Case Presentation The authors present the case of a puerperal woman with systemic lupus erythematosus (SLE) admitted to the emergency room with headache, blurred vision, thoracic pain, and purpuric lesions on both ears. Echocardiogram revealed global decrease in left ventricular function while cardiac and inflammatory markers were elevated. Three days after admission she developed cardiogenic shock due to rupture of mitral papillary muscle which required emergent cardiac surgery, with replacement of the mitral valve; treatment with anticoagulation, high-dose glucocorticoids, and intravenous immunoglobulins were initiated. Cardiac and brain MRI revealed signs of ischemic lesions in both organs. Histopathology analysis of the placenta and papillary muscle showed signs of ischemia secondary to microvascular thrombosis. Based on the clinical demonstration of thrombosis in three organs, and the presence of lupus anticoagulant antibodies, a diagnosis of probable CAPS was established. Conclusion This case highlights the importance of a high level of suspicion of CAPS, particularly in patients with risk factors, and the value of immediate adequate treatment. Moreover, the rupture of a papillary muscle with histologically consistent signs of antiphospholipid syndrome expands the spectrum of involvement of this disease and should be considered as a rare but life-threatening possibility in patients with myocardial injury.

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TDlate-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TDlate-inf (baseline–1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline–6 months) and TDlate-inf (baseline–1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2–4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TDlate-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Background Prior reports of mitral valve surgery (MVS) for ischemic papillary muscle rupture (PMR) have been limited in patient numbers. This study evaluated national outcomes of MVS for PMR using the Society of Thoracic Surgeons (STS) National Database. Methods The study cohort was comprised of patients undergoing MVS for ischemic PMR between 2011 to 2018 in the STS registry. Concomitant procedures were included. The primary outcome was operative mortality. Secondary outcomes included STS major morbidities. Multivariable logistic regression was used for risk-adjustment using clinically important variables as well as those predictive in univariate analysis. Results 1,342 patients underwent MVS for PMR during the study period. The majority of these were mitral valve replacements (79.8%; n=1,071) and were performed emergently (52.0%; n=698). Concomitant coronary artery bypass grafting (CABG) was performed in 59.3% (n=796). Mechanical circulatory assistance prior to MVS included intra-aortic balloon pump (56.9%; n=764), Impella (4.1%; n=55), and extracorporeal membrane oxygenation (3.1%; n=41). STS predicted risk of mortality was 16.9% ± 15.4%. Operative mortality was 20.0%. Blood products were transfused in 70.7% (n=949). Major morbidity rates included prolonged ventilation (61.8%; n=829), acute renal failure (15.4%; n=206), reoperation (10.2%; n=137), and stroke (5.2%; n=70). Multivariable predictors of operative mortality included mitral valve replacement, older age, lower albumin, cardiogenic shock, ejection fraction Conclusions These data provide a national overview of outcomes following MVS for PMR. Rates of mortality and morbidity are high but the majority of patients survive operative intervention in this high-risk and otherwise lethal condition.

A 52-year-old man presented with acute onset of chest pain and was found to have an inferolateral ST-segment elevation myocardial infarction and acute mitral regurgitation due to papillary muscle rupture. This case describes a rare, potentially fatal mechanical complication of acute myocardial infarction. (Level of Difficulty: Beginner.), Graphical abstract

Aims In Fabry cardiomyopathy, left ventricular outflow tract obstruction mimicking hypertrophic cardiomyopathy is a very rare finding, with few cases reported and successfully treated with cardiac surgery. In our population of patients with Fabry disease and severe left ventricular hypertrophy (LVH) at the time of diagnosis, we observed an evolution towards a midventricular obstructive phenotype. Methods and results We present a case series of three classically affected Fabry male patients with significant diagnostic delay and severe cardiac involvement (maximal wall thickness >20 mm) at first evaluation. All patients developed midventricular obstructive form over time despite prompt initiation and optimal compliance to enzyme replacement therapy. The extension and distribution of the LVH, involving the papillary muscles, was the main mechanism of obstruction, unlike the asymmetric septal basal hypertrophy and the mitral valve abnormalities commonly seen as substrate of left ventricular outflow tract obstruction in hypertrophic cardiomyopathy. Conclusions Fabry cardiomyopathy can evolve over time towards a midventricular obstructive form due to massive LVH in classically affected men with significant diagnostic delay and severe LVH before enzyme replacement therapy initiation. This newly described cardiac phenotype could represent an adverse outcome of the disease.

Postpartum papillary muscle rupture (PMR) is extremely uncommon and tolerated poorly with limited management options other than emergency surgical intervention. This case demonstrates the challenges of postpartum PMR in a young woman with unrecognized vascular Ehlers-Danlos syndrome and highlights the importance of preconception screening of cardiovascular disease. (Level of Difficulty: Beginner.), Graphical abstract

Parachute mitral valve is a rare congenital heart defect characterised by a distorted mitral geometry with a single papillary muscle for all mitral chords to attach. It may develop in isolation or as a constillation of Shone syndrome. By comprehensive retrieval of the pertinent articles published since 2000, 22 articles with 149 cases of parachute mitral valve were recruited into this study. The present article revealed that most patients with a parachute mitral valve had a stenotic or regurgitant mitral valve, which is often associated with left heart obstructions, thereby leading to haemodynamic compromise. Therefore, multiple surgical maneuvers are warranted for such patients. Mitral valve repair is preferred over mitral valve replacement for the mitral valve abnormalities so as to avoid the associated complications of valve replacement procedure. The patients' outcomes are satisfactory with a total event-free survival of surgical patients of 84.8%. Key Words: Cardiac surgical procedures, Congenital heart defects, Mitral valve.

Mitral valve prolapse (MVP) affects approximately 170 million people worldwide; however, phenotypically, there is a wide variety of heterogeneity. In particular subsets, the incidence of sudden cardiac death is calculated to be 998 per 100,000 person-years, which is significantly increased when compared with the general population of MVP patients. Individuals with high-risk features have been identified as young females with bileaflet MVP and electrocardiogram findings of frequent complex ectopy, ST-T wave changes, and inferior T wave inversions. Supplemental imaging modalities in this subgroup demonstrate redundant leaflets and chordae on 2-dimensional transthoracic echocardiography along with varying severity of mitral annular disjunction. Detailed morphologic assessment by 3-dimensional echocardiography provides a quantitative assessment of annular disjunction along with left ventricular longitudinal and basal circumferential strain patterns. Late gadolinium enhancement on cardiac magnetic resonance imaging identifies diffuse and isolated left ventricle fibrosis involving the fascicles and papillary muscles, which has been visualized in isolation during autopsy. Findings of this review propose that sudden cardiac death as a result of malignant arrhythmias arises from automaticity, complex ectopy, and reentry at the level of the fascicles and papillary muscles. The repetitive mechanical stress provides a nidus for the development of both micro- and macrofibrosis easily identified by late gadolinium enhancement on cardiac magnetic resonance imaging. Escalation to electrophysiology studies and early intervention could provide new targeted lifesaving therapies.

Background: Mitral valve prolapse (MVP) is characterized by an abnormal movement of the valvular apparatus which may affect the papillary muscles (PMs) function and structure. Aim of the study was to investigate abnormal PM signal in MVP by using cardiac magnetic resonance imaging (MRI). Methods and Results: We enrolled 47 consecutive patients with MVP evaluated by cardiac MRI. Additional groups included healthy volunteers, patients with moderate-to-severe mitral regurgitation (not caused by MVP) and patients with hypertrophic cardiomyopathy. Visual assessment of the PM signals was carried out and the signal intensity (SI) of both the antero-lateral and postero-medial PMs was normalized by that of the left ventricular (LV) parietal myocardium. Our results show that in the MVP group only, the PM signal intensity was significantly lower compared to the one of the LV parietal myocardium. This sign did not correlate with either LV late gadolinium enhancement or positive anamnesis for significant arrhythmias. Conclusions: In MVP patients only, PM signal is significantly reduced compared to LV parietal myocardium (“darker appearance”). The described findings are not clearly related to evidence of myocardial fibrosis, as assessed by MRI, and to previous occurrence of complex ventricular arrhythmias.

BACKGROUND AND AIM OF THE STUDY The aim of this meta-analysis was to compare short- and long-term outcomes of patients undergoing mitral annuloplasty (MA) with or without papillary muscle surgery (PMS) for the treatment of ischemic mitral regurgitation (IMR). METHODS A systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement were performed. RESULTS Nine studies met the inclusion criteria. This meta-analysis identified 478 patients: 228 patients underwent MA alone and 250 patients underwent concomitant PMS. Early mortality was similar between two groups (odds ratio [OR] 1.14, 95% confidence interval [CI], 0.51-2.53; P = .75). PMS was associated at follow-up with a higher freedom from cardiac-related events (P = .050); moreover, although both surgical techniques had a positive impact on ventricular remodeling, the PMS group showed a significant higher reduction of left ventricle end-diastolic diameter (OR, 4.89, 95% CI, 2.77-7.01; P

Background: High recurrent functional ischemic mitral regurgitation (FIMR) has been observed after annuloplasty. Since annuloplasty alone could not prevent late recurrent FIMR or improve the survival rate after CABG, adjunctive subvalvular opt for better treatment tailored for each individual patient. Methods: Ex vivo ovine heart models with annular dilatation and PPM displacement were used for analysis of mitral regurgitation (MR) flow, left ventricular and annular geometry after treatment by mitral annular reduction alone (MA, nMA = 12) or combined with epicardial PPM repositioning (MA+PPM, nMA+PPM=13). Results: MR significantly was reduced from baseline in both the MA (P = .03) and MA+PPM (P = .02) groups, but was not significantly different between the groups. The septo-lateral mitral annular distance decreased after applying both methods (MA group P = .005; MA+PPM group P = .05). The tethering α angle of the APM in the frontal plane significantly increased from baseline in the MA+PPM group (P = .027). Furthermore, the MA+PPM group had a larger APM and PPM α angle in the frontal plane compared with the MA group after reducing the MR (P = .04). There were no statistically significant changes in tethering angles found in the MA group compared with baseline. MR reduction correlated with percentage decrease of septo-lateral mitral annular distance (rs = 0.51, P = .01), the percentage decrease of fibrosa-PPM distance (rs = 0.43, P = .03), and the percentage increase of the PPM anterior displacement (rs = -0.41, P = .04). Conclusion: The decreased tethered angle of the PPM referred to the annulus, and the decreased interpapillary muscles distance suggested the PPM was repositioned inward and toward the septal annulus by the epicardial pushing pad. Epicardial repositioning of the PPM adjunct with mitral annular reduction facilitated leaflet coaptation without the risk of overlying restriction of the mitral annular orifice.

Systolic anterior motion (SAM) of the mitral valve is a well-known complication in mitral valve repair. Because excessive leaflet tissue is an important mechanism, surgical correction is sometimes required to reduce leaflet height or mobility. However, a different approach may be necessary in cases of normal leaflet height. Herein, we describe papillary muscle reorientation for treating SAM after isolated anterior leaflet repair. The papillary muscle heads were approximated and fixed to the posterior ventricular wall, relocating them away from the ventricular septum. This technique is useful for treating postrepair SAM, without addressing the leaflet, in patients with degenerative mitral disease.

Ischemic mitral regurgitation (IMR) is particularly challenging to repair with lasting durability due to the complex valvular and subvalvular pathologies resulting from left ventricular dysfunction. Ex vivo simulation is uniquely suited to quantitatively analyze the repair biomechanics, but advancements are needed to model the nuanced IMR disease state. Here we present a novel IMR model featuring a dilation device with precise dilatation control that preserves annular elasticity to enable accurate ex vivo analysis of surgical repair. Coupled with augmented papillary muscle head positioning, the enhanced heart simulator system successfully modeled IMR pre- and post-surgical intervention and enabled the analysis of adjunctive subvalvular papillary muscle repair to alleviate regurgitation recurrence. The model resulted in an increase in regurgitant fraction: 11.6 ± 1.7% to 36.1 ± 4.4% (p

The surgical management of patients with hypertrophic obstructive cardiomyopathy can be extremely challenging. Relieving the left ventricular outflow tract obstruction in these patients is often achieved by performing a septal myectomy. However, in many instances, septal reduction alone is not enough to relieve the obstruction. Interventions on the sub-valvular apparatus, including the anomalous chordae tendineae and the abnormal papillary muscles, are often required. In this review, we summarize the embryology and the pathophysiology of the different elements that may contribute to the left ventricular outflow tract obstruction in the setting of hypertrophic obstructive cardiomyopathy. In addition, we highlight the different surgical procedures that a surgeon may adopt to relieve the left ventricular outflow tract obstruction, beyond the septal myectomy.

(1) Background: The accuracy of the left ventricular volume (LVV) and contractility measurements with cardiac magnetic resonance imaging (CMRI) is decreased if the papillary muscles are abnormally enlarged, such as in hypertrophic cardiomyopathy in human patients or in pig models of human diseases. The purpose of this work was to establish the best method of LVV quantification with CMRI in pigs. (2) Methods: The LVV in 29 Yucatan minipig hearts was measured using two different techniques: the “standard method”, which uses smooth contouring along the endocardial surface and adds the papillary volume to the ventricular cavity volume, and the “detailed method”, which traces the papillary muscles and trabeculations and adds them to the ventricular mass. (3) Results: Papillary muscles add 21% to the LV mass in normal and infarcted hearts of Yucatan minipigs. The inclusion or exclusion of these from the CMRI analysis significantly affected the study results. In the normal pig hearts, the biggest differences were found in measurements of the LVV, ejection fraction (EF), LV mass and indices derived from the LV mass (p &lt, 0.001). The EF measurement in the normal pig heart was 11% higher with the detailed method, and 19% higher in the infarcted pig hearts (p &lt, 0.0001). The detailed method of endocardium tracing with CMRI closely represented the LV mass measured ex vivo. (4) Conclusions: The detailed method, which accounts for the large volume of the papillary muscles in the pig heart, provides better accuracy and interobserver consistency in the assessment of LV mass and ejection fraction, and might therefore be preferable for these analyses.

We successfully repaired a hammock mitral valve associated with severe mitral valve regurgitation in a 4-month-old boy using posterior leaflet extension along with glutaraldehyde-treated autologous pericardium and the splitting of bilateral papillary muscles. Surgical reinterventions were performed for the bilateral papillary muscles at 14 and 24 months postoperatively. The extended autologous pericardium was still pliable with mild mitral valve regurgitation at 26 months postoperatively.

Mitral regurgitation (MR) is one of the most frequent indications for valve surgery in developed countries, and echocardiographic assessment is an essential tool to evaluate its etiologies, severity, and therapeutic indications. The mitral valve apparatus is a complex structure composed of several parts: apart from the mitral valve leaflets and annulus, it also includes the chordae tendineae, papillary muscles, and left ventricular (LV) wall. MR can be caused not only by organic changes of the mitral valve leaflets or chordae (primary MR) but also by extreme mitral annular enlargement or mitral leaflet tethering due to displacement and malfunction of papillary muscles and LV wall (secondary MR). In secondary MR with LV dysfunction, a milder degree of MR can be associated with adverse outcomes compared with primary MR. Grading the severity is the first step in evaluation of indication for surgical/transcatheter interventions. As such, there are several techniques to assess the severity of MR using echocardiography. However, none of the techniques is reliable enough by itself, and it is always recommended to integrate multiple methods. In cases where echocardiographic assessment of MR severity is inconclusive, magnetic resonance may be helpful. In addition to the severity, anatomical information, such as localization in primary MR due to mitral valve prolapse and LV size in secondary MR due to LV dilatation/dysfunction, is an important concern in presurgical echocardiography. Transesophageal echocardiography and three-dimensional echocardiography are key techniques for anatomical evaluation including mitral valve and LV volumes. In transcatheter intervention for MR, echocardiography plays a pivotal role as a guide for procedures and endpoints. In this review article, the authors provide a comprehensive summary of current standards of echocardiographic assessment of MR.

Background Severe mitral regurgitation (MR) can occur following myocardial infarction (MI) with either partial or complete papillary muscle rupture (pPMR or cPMR). Although the incidence of this complication has significantly decreased, it is still associated with significant mortality. We sought to evaluate the different echocardiographic and clinical presentations of pPMR and cPMR. Methods and results A review of all the urgent procedures for ischemic MR between January 2000 and June 2016 was performed to identify patients who underwent surgery for PMR. Surgical protocols and echocardiographic studies were used to identify patients with cPMR and pPMR. A total of 37 patients had cardiac surgery for PMR (18 cPMR, 19 pPMR). All patients with cPMR were in cardiogenic shock at the time of diagnosis, as opposed to only 53% of patients with pPMR (P = 0.0008). Between the time of diagnosis and surgery, 7 patients with pPMR developed cardiogenic shock. Transthoracic echocardiography (TTE) led to the diagnosis in 72% of cPMR and 32% of pPMR (P = 0.02). TEE had a yield of 100% for both cPMR and pPMR. Six pathologic varieties of post-MI PMR were recognized on echocardiography and during surgery. Early postoperative, 1 (72% vs 84%), 3 (67% vs 84%), and 5 years (67% vs 74%) survival rates were similar for cPMR and pPMR (P = 0.26). Conclusions Partial PMR is associated with a different clinical and echocardiographic presentation than cPMR. Still, most pPMR patients progress toward cardiogenic shock. Prompt diagnosis and referral for surgery are critical and could potentially decrease mortality.

Objective Papillary muscle (PM) displacement contributes to ischemic/functional mitral regurgitation (IMR/FMR). The displaced PMs pull the mitral leaflets into the left ventricle (ie, toward the apex) thus hampering leaflet coaptation. Intuitively apical leaflet tethering results from apical PM displacement. The 3-dimensional directions of PM displacement are, however, incompletely characterized. Methods Data from in vivo ovine models of IMR (6-8 weeks of posterolateral infarction, n = 12) and FMR (9-21 days of rapid left ventricular pacing, n = 11) were analyzed. All sheep had radiopaque markers implanted on the anterior and posterior PM (PPM) tips, around the mitral annulus, and on the left ventricular apex. To explore 3-dimensional PM displacement directions, differences in marker coordinates were calculated at end-systole before and during IMR/FMR using a right-handed coordinate system centered on the mitral annular “saddle horn” with the y-axis passing through the apical marker. Results No apical PM displacement was observed during either IMR or FMR. The anterior PM displaced laterally during FMR. Posterolateral PPM displacement was observed during IMR and FMR. Conclusions Experimental in vivo ovine models suggest posterolateral PPM displacement as a predominant pathomechanism leading to apical leaflet tethering during IMR/FMR.

Background Mitral valve prolapse (MVP) is a common valve condition and has been associated with sudden cardiac death. Premature ventricular contractions (PVCs) from the papillary muscles (PMs) may play a role as triggers for ventricular fibrillation (VF) in these patients. Objectives To characterize the electrophysiological substrate and outcomes of catheter ablation in patients with MVP and PM PVCs. Methods Of 597 patients undergoing ablation of ventricular arrhythmias during the period 2012-2015, we identified 25 patients with MVP and PVCs mapped to the PMs (64% female). PVC-triggered VF was the presentation in 4 patients and a fifth patient died suddenly during follow-up. The left ventricle ejection fraction (LVEF) was 50.5% ± 11.8% and PVC burden was 24.4% ± 13.1%. A cardiac magnetic resonance imaging was performed in nine cases and areas of late gadolinium enhancement were found in four of them. A detailed LV voltage map was performed in 11 patients, three of which exhibited bipolar voltage abnormalities. Complete PVC elimination was achieved in 19 (76%) patients and a significant reduction in PVC burden was observed in two (8%). In patients in which the ablation was successful, the PVC burden decreased from 20.4% ± 10.8% to 6.3% ± 9.5% (P = 0.001). In 5/6 patients with depressed LVEF and successful ablation, the LV function improved postablation. No significant differences were identified between patients with and without VF. Conclusions PM PVCs are a source of VF in patients with MVP and can induce PVC-mediated cardiomyopathy that reverses after PVC suppression. Catheter ablation is highly successful with more than 80% PVC elimination or burden reduction.

A moderate subchronic lead intoxication was observed in male rats after repeated intraperitoneal injections of lead acetate. Right ventricular trabeculae and papillary muscles were isolated for in vitro studying of the contraction-relaxation cycle under isotonic and physiological loading. The contractile function of the myocardium was also assessed by measuring the velocity of thin filament movement over myosin. Lead intoxication led in papillary muscles to a decrease in the maximal rate of isotonic shortening for all afterloads and a decrease in the thin filament sliding velocity. Papillary muscles from lead-exposed rats displayed marked changes in most of the main characteristics of afterload contraction-relaxation cycles, but in trabeculae these changes were less pronounced. The reported changes were attenuated to some extent in rats treated with a Ca-containing bioprotector. The amount of work produced by both types of heart muscle preparations was not changed by lead. Only in papillary muscles the load-dependent relaxation index was significantly increased in the lead-treated groups. Thus subchronic lead intoxication affects the peak rate of force development and relaxation properties of cardiac muscle contracting in isotonic/physiological regimes rather than the total amount of mechanical work, which may reflect adaptive changes in the myocardial function under decreased contractility.

To assess the role of the mitral valve apparatus (leaflets, chordae and papillary muscles, (PM)) in left ventricle outflow tract (LVOT) obstruction, and results of the surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM).Twenty-eight consecutive patients (58±11years, 53% female) undergoing HOCM surgery from 2007 to 2016 at our institute were retrospectively reviewed. Endpoints included the involvement of the mitral valve in LVOT obstruction, mortality, and changes in clinical and echocardiographic characteristics after HOCM surgery.Secondary chordae tendineae tractioning the anterior mitral leaflet to the interventricular septum, and systolic anterior motion were detected in 78% of the patients. Anomalous, hypertrophied, and fused PM with muscularis trabeculae hypertrophy were found in 50%, 25%, and 35% of the patients, respectively. Four patients had posterior leaflet redundancy. Secondary chordae (92%), PM, and muscularis trabeculae resection (71%), and PM splitting and elongation (28%) were added variably to septal myectomy (100%). Nine procedures (32%) on mitral valve leaflets were performed, involving six posterior and three anterior mitral leaflets. Long-term follow-up was 4±2.8years. There was no hospital mortality, and NYHA was reduced from 3±0.5 to 1±0.7 (p0.0001), the LVOT gradient from 88±35 to 20±18mmHg (p0.0001), mitral valve regurgitation from grade 3±1 to 1±0.7 (p0.0001), and septum thickness from 18±3 to 14±2mm (p0.0001).The mitral valve apparatus contributes with all its components variably to LVOT dynamic obstruction thus surgical correction in addition to extended myectomy is recommended to achieve the best outcome.

Demirel-Yilmaz, Emine/0000-0002-2476-6225; Derici, Mehmet Kursat/0000-0002-8260-7492; Guray, Tulin/0000-0003-4572-1429 WOS: 000455010800015 PubMed: 30529467 Phosphodiesterase enzymes (PDEs) are responsible for the adjustment of cyclic nucleotide levels. Alterations in PDE expressions in different tissues cause conflicts between functional and clinical effects of PDE inhibitors. Therefore, the aim of this study was to investigate the gene and protein expressions and the functional role of PDEs in atrium and ventricle of rat heart The expressions of PDEs were examined in cardiac intact tissues and enzymatically isolated cells. The effects of PDE1-5 inhibitors (vinpocetine, EHNA, milrinone, rolipram, sildenafil, and IBMX) on basal and isoprenaline-stimulated contractions and sinus rate were recorded in the isolated spontaneously beating right atrium and electrically stimulated left papillary muscles. The mRNA and protein levels of PDEs were significantly different in atrial and ventricular intact tissues and isolated myocytes. Atrial contractions were increased with vinpocetine while suppressed by EHNA, milrinone, rolipram, sildenafil and IBMX. Milrinone, sildenafil and IBMX increased the heart rate whereas vinpocetine caused negative chronotropy. Papillary muscle contractions have been increased only with the vinpocetine and IBMX. Both the expression and the action of PDE-1-5 show atrial and ventricular differences. Therefore, these differences should be taken into account in the experimental or therapeutic approaches of the heart. Ankara University Research Foundation Ankara, TurkeyAnkara University [13B3330007] This study was supported by a research grants, 13B3330007 from the Ankara University Research Foundation Ankara, Turkey.

A 60-year-old female with premature ventricular contractions (PVCs) originating from the bottom of the posteromedial papillary muscle of the left ventricle underwent radiofrequency catheter ablation (RFCA) using an irrigated-tip catheter. During ablation of the PVCs, a loud steam pop was observed. Intracardiac echocardiography (ICE) revealed a growing, hyperechogenic intramyocardial microbubble formation around the catheter tip. The formation disappeared slowly and completely, leaving an endocardial laceration without pericardial effusion. ICE imaging is valuable during a difficult RFCA procedure, because ICE reveals the exact anatomical position of the catheter and thus allows rapid evaluation of the occurrence of steam popping and any possible subsequent complication.

Mathematical modeling tries to simplify understanding and proposes a fundamental mechanism that governs the motion and function of a complex biological system such as a mitral valve (MV) motion which represents a dynamic interplay between papillary muscle (PM) position in the context of left ventricular (LV) shape dynamics. Current therapeutic strategies to intervene on the MV may not have exploited these relationships due to lack of understanding of the interactions. We present a MV 3D mathematical model characterized by LV shape dynamics to understand fundamental working principles of ventriculo-papillary-mitral complex. A complex 3D functional unit of MV apparatus was mathematically modeled based on a principle of dynamics. The model comprises of primary components including the annulus, anterior leaflet, posterior leaflet, chordae tendineae, anterior and posterior PM, and LV wall based on normal anatomical reference values from published series. Simulations based on Carpentier's classification of MV disease were created as well as based on LV shape dynamics and presented graphically. Autodesk Inventor (Autodesk Inc., San Rafael, CA) and Matlab (Mathworks, Natick, MA) were used for modeling and analysis. A stepwise analysis and mathematical models of the annulus, leaflets, chords, PMs, and LV were obtained by combining finite element analysis and computerized model creations. The model was then applied to Carpentier's functional classification. PM positions extrapolated based on different LV deformation in normal and mitral regurgitation (MR) model resulted in a different degree of MV leaflet coaptation with regurgitation (presented numerically and graphically). Abnormal MV coaptation was amended by manipulating PM positions independent with LV size or shape deformation, demonstrating that PM positioning maneuver may improve leaflet coaptation. LV dilation combined with increased interpapillary muscle distance turned out to intensify the level of leaflet prolapse, creating even greater regurgitation volume. Our mathematical model may provide a clue to complex interactions in play within a mitral, papillary, and LV complex. The model offers a possibility of manipulating various variables to obtain the desired outcome.

A moderator band, also known as the septomarginal trabecula, is a group of muscle bundles located in the ventricle of almost all human hearts. The morphology of the moderator band has various forms and several studies have focused mostly on its structure. Thus, in the present study, we sought to study the morphology and morphometry of the moderator band and tried to rearrange the criteria based on the previous studies to classify the moderator band in Thais. The study investigated 67 formalin-fixed human hearts of both sexes obtained from Thai donors aged 24–101 years with mean age at death 69.92 years. The moderator band was evident in 66 of the 67 specimens (98.51%). The moderator band had the mean or median of overall length, thickness, distance to the base of the tricuspid valve, distance to the base of the pulmonary valve, distance to the apex of the right ventricle, the angle at the septal connection, and angle of the papillary, which were 18.9 ± 6.4 mm, 3.17 (2.04–4.55) mm, 33.0 ± 7.97 mm, 38.8 ± 9.62 mm, 56.4 ± 8.09 mm, 50 (30–105)°, 73.9 ± 30.1°, respectively. The mean distance originating point from the supraventricular crest to the anterior papillary muscle was 0.396 ± 0.07 of the distance from the base of the tricuspid valve to the apex of the right ventricle. Our present classification found that crest-like and thick moderator band with complex secondary branching at high origin (type IVc), and low origin (type IVd) were the most common subtypes. This study provided both anatomical and clinical information that should be useful in cardiac surgery, radiology, and cardiac electrophysiological interventions.

Background The left ventricle is built to carry out its function as a powerful pump. To detail recent findings of anatomical variants associated with the left ventricular compartment, we will first review the external and general features, followed by the internal features and subsequently, the standard variants that can exist within this chamber of the heart. Methods This literature review seeks to collate and discuss peer-reviewed articles on the anatomy of the left ventricle. Results The left ventricle has many unique features including walls that are thicker than those of the right ventricle, an overlap of its inlet and outlet portions, and the hinge of the leaflets of the mitral valve that are oriented cranially relative to those of the tricuspid valve. Conclusion While the left ventricle shares many characteristics with that of the right ventricle, the unique features may contribute to cardiac pathology and can also be used to the surgeon's advantage in treating disease.

BACKGROUND Mitral valve repair with papillary muscle approximation (MVr-PMA) for severe secondary mitral regurgitation (MR) decreases MR recurrence compared with MVr alone. This study assessed the effects of MVr-PMA on left ventricular (LV) remodeling and shape, systolic function and strain mechanics. METHODS Forty-eight patients who underwent MVr-PMA for severe secondary MR and had follow-up echocardiograms available for review were identified. Student's t-test, linear regression modeling, and receiver-operating characteristic curves were used in the statistical analyses. RESULTS Median follow-up time was 14.9 months. MVr-PMA was associated with significant LV reverse remodeling with a smaller LV end-diastolic diameter, systolic sphericity index, and interpapillary muscle distance at follow-up. Nine patients (18.8%) experienced ≥ moderate recurrent MR. When compared recurrent MR patients at follow-up, those with durable MVr-PMA had a greater LV ejection fraction (32.8 vs 22.0%, p=0.03), a smaller end-diastolic diameter (59.6 vs 67.3 mm, p=0.03), systolic sphericity index (0.35 vs 0.47, p=0.03), and endsystolic interpapillary muscle distance (16.3 vs 21.1 mm, p=0.03). A durable MVr-PMA also resulted in stable global longitudinal strain when compared with pre-operative values, while the recurrent MR group experienced a further decline (no recurrent MR: -8.4 vs -7.5%; recurrent MR: -8.2 vs -5.4%; p

OBJECTIVES Entire mitral valve reconstruction with an extracellular matrix tube graft is a potential candidate to overcome the current limitations of mechanical and bioprosthetic valves. However, clinical data have raised concern with respect to patch failure. The aim of our study was to evaluate the impact of extracellular matrix mitral tube graft implantation on mitral annular and subvalvular regional dynamics in pigs. METHODS A modified tube graft design made of 2-ply extracellular matrix was used (CorMatrix®; Cardiovascular Inc., Alpharetta, GA, USA). The reconstructions were performed in an acute 80-kg porcine model (N = 8), where each pig acted as its own control. Haemodynamics were assessed with Mikro-Tip pressure catheters and mitral annular and subvalvular geometry and dynamics with sonomicrometry. RESULTS Catheter-based peak left atrial pressure and pressure difference across the mitral and aortic valves in the reconstructions were comparable to the values seen in the native mitral valves. Also comparable were maximum mitral annular area (755 ± 100 mm2), maximum septal-lateral distance (29.7 ± 1.7 mm), maximum commissure–commissure distance (35.0 ± 3.4 mm), end-systolic annular height-to-commissural width ratio (10.2 ± 1.0%) and end-diastolic interpapillary muscle distance (27.7 ± 3.3 mm). Systolic expansion of the mitral annulus was, however, observed after reconstruction. CONCLUSIONS The reconstructed mitral valves were fully functional without regurgitation, obstruction or stenosis. The reconstructed mitral annular and subvalvular geometry and subvalvular dynamics were found in the same range to those in the native mitral valve. A regional annular ballooning effect occurred that might predispose to patch failure. However, the greatest risk was found at the papillary muscle attachments.

A 46-year-old man presented with left ventricle posteromedial papillary muscle ventricular tachycardia, presyncope, and a type-1 Brugada pattern on the post-electrical cardioversion electrocardiogram. There was a probability of a Brugada syndrome with the expression of its disease in the left ventricle; or a left monomorphic ventricular tachycardia as a part of Brugada phenocopy; or a Brugada syndrome with left monomorphic ventricular tachycardia as an epiphenomenon. Cardiac magnetic resonance, electrophysiological study, and ajmaline test were the key diagnostic tools employed.

Background The threshold-based (TB) trabeculated and papillary muscle mass (TPM) quantification method for cardiac MRI (CMR) calculates different values than conventional contouring techniques. We aimed to identify the sex- and age-related normal reference ranges for left ventricular (LV) myocardial mass values, volumetric and functional parameters and the correspondence of these parameters using the TB method. Methods Healthy European adults (n = 200, age: 39.4 ± 12 years, males: 100) were examined with CMR and evaluated with a TB postprocessing method. They were stratified by sex and age (Group A: 18–29, Group B: 30–39, Group C: 40–49, Group D: >50 years). The calculated parameters were indexed to body surface area (i). Results The normal reference ranges for the studied parameters were assessed in each age group. Significant biometric differences in LV parameters and mass-to-volume ratios were found between males and females, and the left ventricular compacted myocardial mass (LVCMi) and TPMi differences remained significant after stratification by age. Unlike other LV volumetric and functional parameters and mass-to-volume ratios, the TPMi, the LVCMi and the TPMi-to-LVCMi ratio did not differ among age groups in males or females. This finding was strengthened by the lack of correlation between TPMi and age. Conclusions Age- and sex-related normal reference ranges for LV volumetric and functional parameters and LVCMi and TPMi values were established using a TB postprocessing method. TPMi, LVCMi and their ratio did not change over time. The TPMi-to-LVCMi and the mass-to-volume ratios might have clinical utility in the differential diagnosis of conditions with LV hypertrabeculation.

We performed “Papillary muscle heads focalization” for three patients with severe functional mitral regurgitation with severe leaflet tethering (coaptation distance ≥1 cm and/or posterior leaflet angle ≥45 degrees). All separated papillary muscle heads were sutured together and both the anterolateral and posteromedial papillary muscles were reconstructed as single head papillary muscles. The stitches are positioned to adjust the levels of mitral leaflet tips, concerning the length of the marginal chordae connected to each head. A downsized annuloplasty is performed concomitantly. At discharge, no patient showed moderate/severe mitral regurgitation. Their coaptation lengths were 7.1, 8.5, and 8.3 mm.

BackgroundParachute mitral valve with reticular chordae tendineae is an extremely rare anomaly.Case presentationWe present a case of parachute mitral valve associated with distinctive reticular chordae tendineae in an adult. It was diagnosed from the echocardiogram. The patient was referred for surgery. Valve analysis showed thickened mitral valve leaflets and commissures. The chordae tendinae were lengthy and thick. All the chordae tendinae merged into a solitary papillary muscle. A distinctive reticular fibrous tissue was found on mitral valve apparatus as the chordae tendinae intermixed each other. The only functional communication between the left atrium and the left ventricle was through the reticular spaces. This anomaly was considered to be unrepairable and was replaced with a mechanical valve.ConclusionsAn extremely rare and unique case of parachute mitral valve associated with reticular chordae tendineae was reported. Mitral valve replacement is a reasonable choice in patients with parachute mitral valve with reticular chordae tendineae.

BACKGROUND Ablation of ventricular arrhythmias (VA) originating from the left ventricular (LV) papillary muscles (PM) has the potential to damage the mitral valve apparatus resulting in mitral regurgitation (MR). This study sought to evaluate the effect of radiofrequency (RF) ablation of a PM on MR severity. METHODS Patients with pre- and postablation transthoracic echocardiograms who underwent PM ablation for treatment of VA were retrospectively identified and compared to similar patients who underwent VA ablation at non-PM sites. MR severity was evaluated pre- and postablation in both groups and graded as none/trace (Grade 0); mild/mild-to-moderate (Grade 1); moderate (Grade 2); moderate-to-severe/severe (Grade 3). RESULTS A total of 45 and 49 patients were included in the PM and non-PM groups, respectively. There were no significant baseline demographic differences. The PM group had longer RF ablation times (22.3 vs. 13.3 min, p