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BACKGROUND: Little is known about genome-wide changes in the atrial transcriptome as a cause or consequence of atrial fibrillation (AF), and the effect of its common and clinically relevant comorbidity, heart failure (HF).OBJECTIVE: To explore candidate disease processes for atrial fibrillation, we investigated gene expression changes in atrial tissue samples from patients with and without AF, stratified by HF.METHODS: RNA sequencing was performed in right and left atrial appendage tissue in 195 patients undergoing open-heart surgery from centers participating in the CATCH-ME consortium (no history of AF (n=91), paroxysmal AF (n=53) and persistent/permanent AF (n=51)). Analyses were stratified into patients with and without HF (n=75/120), and adjusted for age, sex, atrial side, and a combination of clinical characteristics.RESULTS: We identified 35 genes associated with persistent AF compared to patients without a history of AF, both in the presence or absence of HF (false discovery rateCONCLUSIONS: Analysis of atrial gene expression profiles identified numerous novel genes associated with persistent AF, in presence or absence of HF. Interestingly, no consistent transcriptional changes were associated with paroxysmal AF, suggesting that AF-induced changes in gene expression predominate other changes.

OBJECTIVES Patient-reported quality of life (QOL) has become an important endpoint for arrhythmia surgery for atrial fibrillation (AF). While studies specifically evaluating the effect of arrhythmia surgery on QOL are scarce, we aimed to summarize current evidence of QOL following concomitant and stand-alone arrhythmia surgery for AF. METHODS All studies reporting on QOL using questionnaires from patients undergoing arrhythmia surgery for AF, both stand-alone and concomitant, were included in this systematic review. A meta-analysis was performed on inter-study heterogeneity of changes in QOL on 9 of 12 included studies that used the Short-Form 36 tool and meta-regression based on rhythm outcome after 1 year was executed. Finally, differences in QOL following stand-alone arrhythmia surgery and concomitant procedures were evaluated. RESULTS Overall, QOL scores improved 1 year after surgical ablation for AF evaluated by several questionnaires. In stand-alone arrhythmia procedures, meta-regression showed significant improvements in those who were in sinus rhythm compared to those in AF after 1 year. This association between an improved QOL and the procedural effectiveness was also suggested in concomitant procedures. However, when comparing QOL of patients undergoing cardiac surgery with and without add-on surgical ablation for AF, only the variable ‘physical role’ demonstrated a significant improvement. CONCLUSIONS In patients with AF, QOL improves after both stand-alone and concomitant arrhythmia surgery. In the concomitant group, this improvement can be attributed to both the cardiac procedure itself as well as the add-on arrhythmia surgery. However, both in stand-alone and concomitant procedures, the improvement in QOL seems to be related to the effectiveness of the procedure to maintain sinus rhythm after 12 months.

OBJECTIVE: To describe a cohort of T3-T4 thoracic disc herniations (TDHs), their clinical and radiologic characteristics, and unique thoracoscopic transaxillary approach (TAA).METHODS: All patients operated on for a T3-T4 TDH with minimal follow-up of 1 year were selected.RESULTS: Eight TAA procedures (6 males and 2 females) were included (1.4%). Six patients reported axial pain, irradiating in 2, 4 sensory changes, 1 objective and 1 merely subjective motor weakness. Only 1 TDH was calcified, none was giant, 2 were accompanied by myelomalacia, and 2 by a small segmental syrinx. A cardiothoracic surgeon helped with exposure through a curved axillary incision using anterior cervical and more recently double-ring wound retractors. All patients were operated on using a 10-mm 30° rigid (three-dimensional) high-definition scope. There were no major complications and a good outcome with symptomatic relief in 7 of 8 patients.CONCLUSIONS: T3-T4 TDHs are infrequent but may be underdiagnosed because they tend to be small and their signs and symptoms may mimic a cervical problem involving the shoulders and even the arms. There may be a male predominance. The TAA is straightforward, safe, efficacious, and well tolerated despite the supposed vulnerability of the upper thoracic spinal cord. Dissection between large crowded subpleural veins characteristic for the upper thoracic spine and ensuring adequate dura decompression when the steep angle may partially obscure the tip of the instruments does require some extra time. Thorough knowledge of the unique anatomy of the upper thorax is mandatory and the assistance of a cardiothoracic surgeon is highly recommended.

Background To test in vivo a new design prototype for radio frequency (RF) ablation. Methods A prototype based on a concept of endo-epicardial biparietal bipolar RF ablation with the atrial tissue interposed and consisting of two specular endocardial-epicardial catheters was tested in four pigs (80 +/- 5 kg). The endocardial catheter was introduced into the left atrium through the left atrial appendage on the beating heart. The epicardial counterpart was placed manually on the atrial epicardial surface. The coupling of the two catheters was achieved using a neodymium magnet around the gold plate electrode, and RF was applied to the interposed tissue. The hearts were excised, and the lesions were examined using morphometric evaluation. Results The RF application resulted in transmural lesions in all of the four animals tested. In these animals the maximum endocardial width (W-endo) was 6.34 +/- 0.25, 6.54 +/- 0.33, 6.36 +/- 0.57, and 6.49 +/- 0.96 mm. The pericardial width (W-epi) was similar: 6.37 +/- 0.47, 6.58 +/- 0.32, 6.35 +/- 0.56 and 6.53 +/- 0.94 mm. The lesion area was 924.78, 949.25, 944.25, and 926.05 mm(2), and the lesion volume was 92.47, 94.92, 94.42, and 92.60 mm(3), respectively. Conclusions The idea of an endocardial-epicardial bidirectional biparietal bipolar radiofrequency tool such that the atrial tissue is fully interposed between the two RF poles might be promising for future clinical applications. Further research is warranted.

OBJECTIVES Thoracoscopic ablation for atrial fibrillation (AF) and minimally invasive direct coronary artery bypass (MIDCAB) with robot-assisted left internal mammary artery (LIMA) harvesting may represent a safe and effective alternative to more invasive surgical approaches via sternotomy. The aim of our study was to describe the feasibility, safety and efficacy of a unilateral left-sided thoracoscopic AF ablation and concomitant MIDCAB surgery. METHODS Retrospective analysis of a prospectively gathered cohort was performed of all consecutive patients with AF and at least a critical left anterior descending artery (LAD) stenosis that underwent unilateral left-sided thoracoscopic AF ablation and concomitant off-pump MIDCAB surgery in the Maastricht University Medical Centre between 2017 and 2021. RESULTS Twenty-three patients were included [age 69 years (standard deviation = 8), paroxysmal AF 61%, left atrial volume index 42 ml/m2 (standard deviation = 11)]. Unilateral left-sided thoracoscopic isolation of the left (n = 23) and right (n = 22) pulmonary veins and box (n = 21) by radiofrequency ablation was succeeded by epicardial validation of exit- and entrance block (n = 22). All patients received robot-assisted LIMA harvesting and off-pump LIMA-LAD anastomosis through a left mini-thoracotomy. The perioperative complications consisted of one bleeding of the thoracotomy wound and one aborted myocardial infarction not requiring intervention. The mean duration of hospital stay was 6 days (standard deviation = 2). After discharge, cardiac hospital readmission occurred in 4 patients (AF n = 1; pleural- and pericardial effusion n = 2, myocardial infarction requiring the percutaneous intervention of the LIMA-LAD n = 1) within 1 year. After 12 months, 17/21 (81%) patients were in sinus rhythm when allowing anti-arrhythmic drugs. Finally, the left atrial ejection fraction improved postoperatively [26% (standard deviation = 11) to 38% (standard deviation = 7), P = 0.01]. CONCLUSIONS In this initial feasibility and early safety study, unilateral left-sided thoracoscopic AF ablation and concomitant MIDCAB for LIMA-LAD grafting is a feasible, safe and efficacious for patients with AF and a critical LAD stenosis.

OBJECTIVES To evaluate the role of P-wave parameters, as defined on preprocedural electrocardiography (ECG), in predicting atrial fibrillation after cardiac surgery [postoperative atrial fibrillation (POAF)]. METHODS PubMed, Cochrane library and Embase were searched for studies reporting on P-wave parameters and risk of POAF. Meta-analysis of P-wave parameters reported by at least 5 different publications was performed. In case of receiver operator characteristics (ROC-curve) analysis in the original publications, an ROC meta-analysis was performed to summarize the sensitivity and specificity. RESULTS Thirty-two publications, with a total of 20 201 patients, contributed to the meta-analysis. Increased P-wave duration, measured on conventional 12-lead ECG (22 studies, Cohen’s d = 0.4, 95% confidence interval: 0.3–0.5, P CONCLUSIONS This meta-analysis shows that increased P-wave duration, measured on conventional 12-lead ECG and signal-averaged ECG, predicted POAF in patients undergoing cardiac surgery.

BACKGROUND: Hybrid ablation (HA) of atrial fibrillation (AF) combines minimally invasive thoracoscopic epicardial ablation with transvenous endocardial electrophysiologic validation and touch-up of incomplete epicardial lesions if needed. While studies have reported on a bilateral thoracoscopic HA approach, data on a unilateral left-sided approach are scarce.AIM: To evaluate the efficacy and safety of a unilateral left-sided thoracoscopic approach.METHODS: Retrospective analysis of a prospectively gathered cohort of all consecutive patients undergoing a unilateral left-sided HA for AF between 2015 and 2018 in the Maastricht University Medical Centre.RESULTS: One-hundred nineteen patients were analyzed (mean age 64 ± 8, 28% female, mean body mass index 28 ± 4 kg/m2 , median CHA2 DS2 -VASc Score 2 [1-3], [longstanding]-persistent AF 71%, previous catheter ablation 44%). In all patients, a unilateral left-sided HA consisting of pulmonary vein (PV) isolation, posterior left atrial (LA) wall isolation, and LA appendage exclusion was attempted. Epicardial (n = 59) and/or endocardial validation (n = 81) was performed and endocardial touch-up was performed in 33 patients. Major peri-operative complications occurred in 5% of all patients. After 12 and 24 months, the probability of being free from supraventricular tachyarrhythmia recurrence was 80% [73-87] and 67% [58-76], respectively, when allowing antiarrhythmic drugs.CONCLUSION: Unilateral left-sided hybrid AF ablation is an efficacious and safe approach to treat patients with paroxysmal and (longstanding) persistent AF. Future studies should compare a unilateral with a bilateral approach to determine whether a left-sided approach is as efficacious as a bilateral approach and allows for less complications.

Aims This systematic review and meta-analysis aims to evaluate the role of pre-operative transthoracic echocardiography in predicting post-operative atrial fibrillation (POAF) after cardiac surgery. Methods and results Electronic databases were searched for studies reporting on pre-operative echocardiographic predictors of POAF in PubMed, Cochrane library, and Embase. A meta-analysis of echocardiographic predictors of POAF that were identified by at least five different publications was performed. Forty-three publications were included in this systematic review. Echocardiographic predictors for POAF included surrogate parameters for total atrial conduction time (TACT), structural cardiac changes, and functional disturbances. Meta-analysis showed that prolonged pre-operative PA-TDI interval [5 studies, Cohen’s d = 1.4, 95% confidence interval (CI) 0.9–1.9], increased left atrial volume indexed for body surface area (LAVI) (23 studies, Cohen’s d = 0.8, 95% CI 0.6–1.0), and reduced peak atrial longitudinal strain (PALS) (5 studies, Cohen’s d = 1.4, 95% CI 1.0–1.8), were associated with POAF incidence. Left atrial volume indexed for body surface was the most important predicting factor in patients without a history of AF. These parameters remained important predictors of POAF in heterogeneous populations with variable age and comorbidities such as coronary artery disease and valvular disease. Conclusion This meta-analysis shows that increased TACT, increased LAVI, and reduced PALS are valuable parameters for predicting POAF in the early post-operative phase in a large variety of patients.

Background The development of atrial fibrillation (AF) is a complex multifactorial process. Over the past few decades, much has been learned about the pathophysiological processes that can lead to AF from a variety of specific disease models in animals. However, our ability to recognise these disease processes in AF patients is still limited, which has contributed to the limited progress in improving rhythm control in AF. Aims/objectives We believe that a better understanding and detection of the individual pathophysiological mechanisms underlying AF is a prerequisite for developing patient-tailored therapies. The RACE V Tissue Bank Project will contribute to the unravelling of the main molecular mechanisms of AF by studying histology and genome-wide RNA expression profiles and combining this information with detailed phenotyping of patients undergoing cardiac surgery. Methods As more and more evidence suggests that AF may occur not only during the first days but also during the months and years after surgery, we will systematically study the incidence of AF during the first years after cardiac surgery in patients with or without a history of AF. Both the overall AF burden as well as the pattern of AF episodes will be studied. Lastly, we will study the association between the major molecular mechanisms and the clinical presentation of the patients, including the incidence and pattern of AF during the follow-up period. Conclusion The RACE V Tissue Bank Project combines deep phenotyping of patients undergoing cardiac surgery, including rhythm follow-up, analysis of molecular mechanisms, histological analysis and genome-wide RNA sequencing. This approach will provide detailed insights into the main pathological alterations associated with AF in atrial tissue and thereby contribute to the development of individualised, mechanistically informed patient-tailored treatment for AF.

Europace : the European journal of pacing, arrhythmias and cardiac electrophysiology 24(6), 1037-1038 (2022). doi:10.1093/europace/euab317, Published by Oxford Univ. Press, Oxford

Aims Repetitive conduction patterns in atrial fibrillation (AF) may reflect anatomical structures harbouring preferential conduction paths and indicate the presence of stationary sources for AF. Recently, we demonstrated a novel technique to detect repetitive patterns in high-density contact mapping of AF. As a first step towards repetitive pattern mapping to guide AF ablation, we determined the incidence, prevalence, and trajectories of repetitive conduction patterns in epicardial contact mapping of paroxysmal and persistent AF patients. Methods and results A 256-channel mapping array was used to record epicardial left and right AF electrograms in persistent AF (persAF, n = 9) and paroxysmal AF (pAF, n = 11) patients. Intervals containing repetitive conduction patterns were detected using recurrence plots. Activation movies, preferential conduction direction, and average activation sequence were used to characterize and classify conduction patterns. Repetitive patterns were identified in 33/40 recordings. Repetitive patterns were more prevalent in pAF compared with persAF [pAF: median 59%, inter-quartile range (41–72) vs. persAF: 39% (0–51), P Conclusion High-density epicardial contact mapping in AF patients reveals frequent repetitive conduction patterns. In persistent AF patients, repetitive patterns were less frequent, smaller, and more variable than in paroxysmal AF patients. Future research should elucidate whether these patterns can help in finding AF ablation targets.

ObjectiveTo evaluate the size and depth of linear lesions by in vitro testing with a custom-made radio frequency biparietal bipolar ablation catheter in a single-stage setting.MethodsA custom-made catheter was created to generate linear lesions around the left atrium and pulmonary veins of an ex vivo pig. Two frames were made, 1 epicardial and 1 endocardial. A continuous copper braid electrode and an alignment system consisting of 2 parallel rows of neodymium magnets were embedded in a flexible plastic support. After 24 hours of formalin conservation, samples of the left atrium of a freshly slaughtered pig were sliced in a cryotome, thus obtaining a sequence of 100-µm thick layers extending from the endocardial to the epicardial side. After being digitized through a scanner, these layers were evaluated using morphometric computer software. For each slice, we evaluated the maximum length of the lesions, the maximum epicardial length, the maximum endocardial length, the total area of the lesion, and the total volume.ResultsForty transmural lesions from 40 specimens were obtained. The results were the following (the number in parenthesis is the interquartile range in mm): lesion maximum length ( LMAX) was 7.297 mm (0.006), epicardial maximum length ( LEPI) was 7.291 mm (0.014), and endocardial maximum length was 7.291 mm (0.018). The total area and total volume were 1018.50 ± 36.51 mm2and 101.85 ± 3.65 mm3, respectively.ConclusionsOur prototype showed very promising results. The next step will be to enhance the design for clinical application.

INTRODUCTION AND OBJECTIVES: Recent observations suggest that patients with a previous failed catheter ablation have an increased risk of atrial fibrillation (AF) recurrence after subsequent thoracoscopic AF ablation. We assessed the risk of AF recurrence in patients with a previous failed catheter ablation undergoing thoracoscopic ablation.METHODS: We included patients from 3 medical centers. To correct for potential heterogeneity, we performed propensity matching to compare AF freedom (freedom from any atrial tachyarrhythmia > 30 s during a 1-year follow-up). Left atrial appendage tissue was analyzed for collagen distribution.RESULTS: A total of 705 patients were included, and 183 had a previous failed catheter ablation. These patients had fewer risk factors for AF recurrence than ablation naïve controls: smaller indexed left atrial volume (40.9 ± 12.5 vs 43.0 ± 12.5 mL/m2, P = .048), less congestive heart failure (1.5% vs 8.9%, P = .001), and less persistent AF (52.2% vs 60.3%, P = .067). However, AF history duration was longer in patients with a previous failed catheter ablation (6.5 [4-10.5] vs 4 [2-8] years; P CONCLUSIONS: Patients with a prior failed catheter ablation had fewer risk factors for AF recurrence but more frequently had AF recurrence after thoracoscopic AF ablation than ablation naïve patients. This may in part be explained by more progressed, subclinical, atrial fibrosis formation.

Aims Although in persistent atrial fibrillation (AF) a complex AF substrate characterized by a high incidence of conduction block has been reported, relatively little is known about AF complexity in paroxysmal AF (pAF). Also, the relative contribution of various aspects of structural alterations to conduction disturbances is not clear. In particular, the contribution of endomysial fibrosis to conduction disturbances during progression of AF has not been studied yet. Methods and results During cardiac surgery, epicardial high-density mapping was performed in patients with acutely induced (aAF, n = 11), pAF (n = 12), and longstanding persistent AF (persAF, n = 9) on the right atrial (RA) wall, the posterior left atrial wall (pLA) and the LA appendage (LAA). In RA appendages, overall and endomysial (myocyte-to-myocyte distances) fibrosis and connexin 43 (Cx43) distribution were quantified. Unipolar AF electrogram analysis showed a more complex pattern with a larger number of narrower waves, more breakthroughs and a higher fractionation index (FI) in persAF compared with aAF and pAF, with no differences between aAF and pAF. The FI was consistently higher at the pLA compared with the RA. Structurally, Cx43 lateralization increased with AF progression (aAF = 7.5 ± 8.9%, pAF = 24.7 ± 11.1%, persAF = 35.1 ± 11.4%, P < 0.001). Endomysial but not overall fibrosis correlated with AF complexity (r = 0.57, P = 0.001; r = 0.23, P = 0.20; respectively). Conclusions Atrial fibrillation complexity is highly variable in patients with pAF, but not significantly higher than in patients with acutely induced AF, while in patients with persistent AF complexity is higher. Among the structural alterations studied, endomysial fibrosis, but not overall fibrosis, is the strongest determinant of AF complexity.

Objective It is unknown whether epicardial and endocardial validation of bidirectional block after thoracoscopic surgical ablation for atrial fibrillation is comparable. Epicardial validation may lead to false-positive results due to epicardial tissue edema, and thus could leave gaps with subsequent arrhythmia recurrence. It is the aim of the present study to answer this question in patients who underwent hybrid atrial fibrillation ablation (combined thoracoscopic epicardial and endocardial catheter ablation). Methods After epicardial ablation of the pulmonary veins (PVs) and connecting inferior and roof lines (box lesion), exit and entrance block were epicardially and endocardially evaluated using an endocardial His Bundle catheter and electrophysiological workstation. If incomplete lesions were found, endocardial touch-up ablation was performed. Validation results were also compared to predictions about conduction block based on tissue conductance measurements of the epicardial ablation device. Results Twenty-five patients were included. Epicardial validation results were 100% equal to the endocardial results for the left superior, left inferior, and right inferior PVs and box lesion. For the right superior PV, 85% similarity was found. Based on tissue conductance measurements, 139 lesions were expected to be complete; however, in 5 (3.6%) a gap was present. Conclusions Epicardial bidirectional conduction block in the PVs and the box lesion corresponded well with endocardial bidirectional conduction block. Conduction block predictions by changes in tissue conductance failed in few cases compared to block confirmation. This emphasizes that tissue conduction measurements can provide a rough indication of lesion effectiveness but needs endpoint confirmation by either epicardial or endocardial block testing.

Purpose To make an in vitro evaluation of the lesion size and depth produced in two different sets of radio frequency energy bipolar delivery: simultaneous biparietal bipolar (SBB) and simultaneous uniparietal bipolar (SUB). Methods Two separate prototypes have been built for our purpose: one to be used in SBB mode and the other to be used SUB mode. Forty left atrium samples were taken from the hearts of freshly slaughtered pigs. They were ablated into a simulator ABLABOX, where blood flow, temperature, and contact force were controlled. After being sliced into a cryotome, the samples were digitalized by a flatbed scanner, and the images were analyzed by a computer morphometric software. Results Transmural lesions were achieved in 18/20 samples (90%) in SBB, while SUB showed transmurality in 9/20 samples (45%). Overall maximum diameter (DMAX) resulted larger in SUB than in SBB (2.43 ± 0.30 mm, 1.62 ± 0.14 mm, respectively; p DEPI and DENDO, respectively) were wider in SUB group than SBB group (2.28 ± 0.30 mm, 2.26 ± 0.40 and 1.60 ± 0.14 mm, 1.59 ± 0.15 mm, respectively; p ATOT and VTOT) were broader in SUB group than in SBB one (581.01 ± 65.38 mm/mm2, 58.10 ± 6.53 mm/mm3 and 521.97 ± 73.05 mm/mm2, 52.19 ± 7.30 mm/mm3. respectively; p Conclusions In contrast with the smaller lesion sizes, the biparietal bipolar group showed a higher transmurality rate. These findings may suggest a better drive of the energy flow when compared with SUB lesions.

Objective To compare lesion size and depth between a 1-step, a sequential, and a delayed radio-frequency ablation in a hybrid setup. Methods Left atrium tissues obtained from fresh porcine hearts were mounted into the ABLABOX simulator. Based on the time differences between the index epicardial (epi) and consequent endocardial (endo) ablation, 3 study groups were compared: a 1-stage (SEQ- 0) group (0-minute delay), an SEQ 1 group (60-minute delay), and an SEQ 2 group (240-minute delay). During the experiment, a constant epicardial (300 gr) and endocardial (30 gr) force were applied. Per group, 20 samples were studied, and the resulting lesion size and depth were quantified with morphometric evaluation. Results Overall, no transmural lesion was obtained. Lesions in SEQ 0 had better maximum and minimum diameters ( P < 0.001), a larger total area ( P < 0.001), and volume ( P < 0.001) than SEQ 1 and SEQ 2. There was no statistical difference in morphometric parameters (all, P > 0.05) between the delayed procedures (SEQ 1 and SEQ 2). Conclusions In our in vitro model, different time sequences of combined epi–endo ablation did not result in transmural lesions. However, simultaneous epi–endo ablation produced broader and deeper lesions. Our findings need to be confirmed by further research.

Background The use of temporary mechanical circulatory support (tMCS) during arrhythmia is increasing, although available evidence for this indication is limited, with significant gaps of knowledge regarding appropriate timing, management and configuration. This systematic review sought to analyze the use of tMCS in patients with life-threatening arrhythmia. Methods A systematic literature search identified 2529 references published until September 2019. Adult and pediatric patients diagnosed with all kind of life-threatening arrhythmia were included. tMCS was primarily compared to conventional non-tMCS therapies. Primary outcome measure was in-hospital or 30-day mortality. Results 19 non-randomized studies were selected, including 2465 adult and 82 pediatric patients. Primary outcome in tMCS patients varied widely (4–62%) with differences based on the use of prophylactic tMCS (4–21%) or rescue tMCS (58–62%). A substantial mortality benefit was observed among high-risk patients, as identified with PAINESD risk score or suffering from electrical storm and treated with prophylactic tMCS. During ablation procedures, tMCS patients showed higher rates of induced ventricular tachycardias (VTs), ablated VTs, VT termination and non-inducibility after ablation. Extracorporeal membrane oxygenation (ECMO) was applied in pediatric cases as hemodynamic protection for aggressive antiarrhythmic medical treatment with >80% survival. Conclusions Prophylactic tMCS is associated with improved survival as compared to rescue or no-tMCS in patients with life-threatening arrhythmia, and may be considered in patients with high PAINESD risk score or suffering from electrical storm. ECMO can be advised as rescue and support therapy in pediatric cases requiring aggressive antiarrhythmic medical treatment.

Background Surgical epicardial atrial fibrillation (AF) ablation can be performed as a stand-alone (thoracoscopic) procedure or concomitant to other cardiac surgery. In hybrid AF ablation thoracoscopic surgical epicardial ablation is combined with a percutaneous endocardial ablation. The Medtronic Gemini-S clamp is a surgical tool that uses irrigated bipolar biparietal radiofrequency (RF) energy applied with two clamp lesions that overlap to create one epicardial box lesion including the posterior left atrial wall and the pulmonary veins. Case summary We describe three patients with therapy-refractory persistent AF and different stages of atrial remodelling in whom the Medtronic Cardioblate Gemini-S Irrigated RF Surgical Ablation System was used for hybrid AF ablation. Acute endocardial validation at the end of the hybrid ablation revealed a complete box lesion in all three cases. At 2-year follow-up, two out of three patients had recurrence of atrial arrhythmias. Invasive electro-anatomical mapping confirmed the persistence of the box lesion, and the mechanism of arrhythmia recurrence in both patients was unrelated to posterior left atrium or the pulmonary veins. The third patient has been without arrhythmia symptoms since the ablation procedure. A three-dimensional late gadolinium enhancement magnetic resonance imaging illustrates the ablation scar non-invasively in two cases. Discussion Thoracoscopic biparietal RF AF ablation with the Medtronic Cardioblate Gemini-S Irrigated RF Surgical Ablation System results in permanent transmural scar formation, irrespective of the stage of atrial remodelling, as shown in this small population by means of multimodality scar evaluation.

Aims Postoperative atrial fibrillation (POAF) after cardiac surgery is an independent predictor of stroke and mortality late after discharge. We aimed to determine the burden and predictors of early (up to 5th postoperative day) and late (after 5th postoperative day) new-onset atrial fibrillation (AF) using implantable loop recorders (ILRs) in patients undergoing open chest cardiac surgery. Methods and results Seventy-nine patients without a history of AF undergoing cardiac surgery underwent peri-operative high-resolution mapping of electrically induced AF and were followed 36 months after surgery using an ILR (Reveal XT™). Clinical and electrophysiological predictors of late POAF were assessed. POAF occurred in 46 patients (58%), with early POAF detected in 27 (34%) and late POAF in 37 patients (47%). Late POAF episodes were short-lasting (mostly between 2 min and 6 h) and showed a circadian rhythm pattern with a peak of episode initiation during daytime. In POAF patients, electrically induced AF showed more complex propagation patterns than in patients without POAF. Early POAF, right atrial (RA) volume, prolonged PR time, and advanced age were independent predictors of late POAF. Conclusions Late POAF occurred in 47% of patients without a history of AF. Patients who develop early POAF, with higher age, larger RA, or prolonged PR time have a higher risk of developing late POAF and may benefit from intensified rhythm follow-up after cardiac surgery. Clinicaltrials.gov number NCT01530750.

Background When compared with older reports of untreated symptomatic aortic valve stenosis (AoS), urgent transcatheter aortic valve implantation (u-TAVI) seems to improve mortality rates. We performed a single centre, retrospective cohort analysis to characterize our u-TAVI population and to identify potential predictors of worse outcomes. Methods We performed a retrospective analysis of 631 consecutive TAVI patients between 2013 and 2018. Of these patients, 53 were categorized as u-TAVI. Data was collected from the local electronic database. Results Urgent patients had more often a severely decreased left ventricular ejection fraction (LVEF p = 0.001). Urgent patients were hospitalised for 18 [10–28] days before and discharged 6 [4–9] days after the implantation. The incidence of peri-procedural complications and apical implantations was comparable among the study groups. Urgent patients had higher in-hospital (11.3% vs 3.1%; p = 0.011) and 1-year mortality rates (28.2% vs 8.5%, p p p = 0.016) and cerebrovascular complications (HR 4.3; p = 0.002). Within the urgent group, the length of pre-hospital admission was the only significant predictor of 1-year mortality (HR 1.037/day; p = 0.003). Conclusions Compared to elective procedures, u-TAVI led to increased mortality and comparable complication rates. This detrimental effect is most likely related to the length of pre-procedural hospitalisation of urgent patients.

Background Life-threatening arrhythmias have been reported in patients with severe pectus excavatum in absence of other cardiac abnormalities. Literature is scarce regarding diagnosis, cause and management of this problem, particularly regarding the question as to whether the placement of an implantable cardioverter-defibrillator (ICD) is necessary. Case summary A 19-year-old male patient with severe pectus excavatum was scheduled for elective surgical correction. During forward bending for epidural catheter placement, syncope and ventricular fibrillation (VF) occurred resulting in cardiac arrest. After successful cardiopulmonary resuscitation, extensive analysis was performed and showed no cause for VF other than cardiac compression (particularly of the left atrium, right atrium, and ventricle to a lesser degree) due to severe pectus excavatum. Postponed correction by modified Ravitch was performed without ICD placement, with an uneventful post-operative recovery. Eighteen months after surgery, the patient remains well. Upon specific request, he did remember dizzy spells when tying shoelaces. He always considered this unremarkable. Discussion In severe pectus excavatum with cardiac compression, forward bending can decrease central venous return and cardiac output, causing hypotension, arrhythmia, and cardiac arrest. In absence of structural or electric abnormalities, cardiac compression by severe pectus excavatum was considered a reversible cause of VF and ICD placement unnecessary. Patients with cardiac compression due to severe pectus excavatum may report pre-existing postural symptoms upon specific request. When these postural symptoms are present, extreme and prolonged forward bending postures should be avoided.

OBJECTIVESThe aim of this study was to evaluate the lesion size and depth of radiofrequency (RF) ablation in a simultaneous biparietal bidirectional bipolar (SBB) approach, compared to a simultaneous and staged unipolar and uniparietal bipolar setup [simultaneous uniparietal bipolar (SiUB) and staged uniparietal bipolar (StUB), respectively].METHODSFresh left atrial porcine tissue was mounted into the ABLA-BOX simulator. Different ablation approaches were tested: (i) SBB: a concept consisting of SBB endo-epicardial ablation, (ii) SiUB: simultaneous epicardial uniparietal bipolar and endocardial unipolar ablation and (iii) StUB: staged epicardial uniparietal bipolar and endocardial unipolar ablation. In the StUB setup, a 1-h interval between the epi-endo ablation was respected.RESULTSTransmural lesions were present in 90% of the bipolar biparietal ablations, yet no full transmurality was observed in the simultaneous nor in the staged unipolar with uniparietal bipolar ablation group. In SBB, the area and volume of the ablation lesions were smaller (523.33 mm2/mm and 52.33 mm3/mm, respectively) than in SiUB (588.17 mm2/mm and 58.81 mm3/mm, respectively) and StUB (583.76 mm2/mm and 58.37 mm3/mm, P = 0.044). Also, in SBB, the overall, epicardial and endocardial maximum diameters of the lesions (1.59, 1.57 and 1.52 mm; respectively) were smaller than in SiUB (2.38, 2.26 and 2.33 mm; respectively) and in StUB (2.36, 2.28 and 2.14 mm; respectively, all P CONCLUSIONSAlthough bipolar biparietal bidirectional RF ablation results in smaller lesions than uniparietal bipolar and unipolar ablation, their capacity to penetrate the tissue is much higher. Moreover, in uniparietal RF applications, the energy spreads in the superficial layers of the tissue but fails to penetrate. Therefore, the degree of transmurality is much higher when using such a ‘truly bipolar’ ablation approach.