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INTRODUCTION: Previous cardiovascular disease (CVD) and myocardial involvement are common in coronavirus disease-19 (COVID-19). We investigated relationships between CVD, cardiac biomarkers and outcome in COVID-19. METHODS: We analyzed n = 252 patients from a multicenter study and provided comparison according to the presence or absence of underlying CVD. Cardiac biomarkers high-sensitivity Troponin [upper reference of normality (URN) 35 pg/ml for Troponin I and 14 pg/ml for Troponin T] and natriuretic peptides (Nt-pro-B-type natriuretic peptide, URN 300 pg/ml and B-type natriuretic peptide, URN 100 pg/ml) were both available in n = 136. RESULTS: Mean age was 69 ±â€Š16 years (56% men, 31% with previous CVD). Raised hs-Troponin and natriuretic peptides were detected in 36 and 50% of the cases respectively. Age, chronic obstructive pulmonary disease, hemoglobin, hs-Troponin and natriuretic peptides were independently associated with underlying CVD (P 

Aims myocardial involvement in the course of Coronavirus disease 2019 (COVID-19) pneumonia has been reported, though not fully characterized yet. Aim of the present study is to undertake a joint evaluation of hs-Troponin and natriuretic peptides (NP) in patients hospitalized for COVID-19 pneumonia. Methods and results in this multicenter observational study, we analyzed data from n = 111 COVID-19 patients admitted to dedicated “COVID-19” medical units. Hs-Troponin was assessed in n = 103 patients and NP in n = 82 patients on admission; subgroups were identified according to values beyond reference range. increased hs-Troponin and NP were found in 38% and 56% of the cases respectively. As compared to those with normal cardiac biomarkers, these patients were older, had higher prevalence of cardiovascular diseases (CVD) and more severe COVID-19 pneumonia by higher CRP and D-dimer and lower PaO2/FIO2. Two-dimensional echocardiography performed in a subset of patients (n = 24) showed significantly reduced left ventricular ejection fraction in patients with elevated NP only (p = 0.02), whereas right ventricular systolic function (tricuspid annular plane systolic excursion) was significantly reduced both in patients with high hs-Troponin and NP (p = 0.022 and p = 0.03 respectively). On multivariable analysis, independent associations were found of hs-Troponin with age, PaO2/FIO2 and D-dimer (B = 0.419, p = 0.001; B=-0.212, p = 0.013 and B = 0.179, p = 0.037 respectively), and of NP with age and previous CVD (B = 0.480, p Conclusion myocardial involvement at admission is common in COVID-19 pneumonia and associated to worse prognosis, suggesting a role for cardiac biomarkers assessment in COVID-19 risk stratification. Independent associations of hs-Troponin with markers of disease severity and of NP with underlying CVD might point towards existing different mechanisms leading to their elevation in this setting.

OBJECTIVE: Noninvasive positive-pressure ventilation (NPPV) emerged as an efficient tool for treatment of COVID-19 pneumonia. The factors influencing NPPV failure still are elusive. The aim of the study was to investigate the relationships between semiquantitative chest computed tomography (CT) scoring and NPPV failure and mortality in patients with COVID-19. DESIGN: Observational study. SETTING: Nonintensive care setting. PARTICIPANTS: A total of 112 patients consecutively admitted for COVID-19 pneumonia. INTERVENTIONS: Usual care including various degrees of respiratory support. MEASUREMENTS AND MAIN RESULTS: The semiquantitative CT score was calculated at hospital admission. Subgroups were identified according to the ventilation strategy used (oxygen delivered by Venturi mask n = 53; NPPV-responder n = 38; NPPV-failure n = 21). The study's primary endpoint was the use of NPPV. The secondary endpoints were NPPV failure and in-hospital death, respectively. CT score progressively increased among groups (six v nine v 14, p < 0.05 among all). CT score was an independent predictor of all study endpoints (primary endpoint: 1.25 [95% confidence interval {CI} 1.1-1.4], p = 0.001; NPPV failure: 1.41 [95% CI 1.18-1.69], p < 0.001; in-hospital mortality: 1.21 [95% CI 1.07-1.38], p = 0.003). According to receiver operator characteristics curve analysis, CT score was the most accurate variable for prediction of NPPV failure (area under the curve 0.862 with p < 0.001; p < 0.05 v other variables). CONCLUSIONS: The authors reported the common and effective use of NPPV in patients with COVID-19 pneumonia. In the authors' population, a semiquantitative chest CT analysis at hospital admission accurately identified those patients responding poorly to NPPV.

CHA2DS2-VASc score associates with worse prognosis in coronavirus-disease-19 (COVID-19). This study investigated laboratory correlates of increasing CHA2DS2-VASc in patients with COVID-19. Patients with COVID-19 were stratified by CHA2DS2-VASc (Group 1: CHA2DS2-VASc 0-1; Group 2: CHA2DS2-VASc 2-3; Group 3: CHA2DS2-VASc ≥4). We found stepwise increase of D-dimer, hs-Troponin and in-hospital mortality across groups (all P 

Background: lung ultrasound (LUS) and chest computed tomography (chest-CT) are largely employed to evaluate coronavirus-disease-19 (COVID-19) pneumonia. We investigated semi-quantitative LUS and CT scoring in hospitalized COVID-19 patients.Methods: LUS and chest-CT were performed within 24 hours upon admission. Both were analyzed according to semi-quantitative scoring systems. Subgroups were identified according to median LUS score.Results: patients within higher LUS-score group were older (79 vs 60 years, pConclusions: semi-quantitative bedside LUS related to the severity of COVID-19 pneumonia similarly to chest-CT. Correlation of LUS-score with markers of cardiac and renal injury suggests that LUS might contribute to a more comprehensive evaluation of this heterogeneous population.

In-hospital course of patients with Takotsubo syndrome (TS) is quite heterogeneous and life-threatening complications are not uncommon in the acute phase. The role of heart rate (HR) as a predictor of prognosis has not been sufficiently investigated in this setting. The study aims to assess the impact of HR at presentation on in-hospital course of patients with TS.The study population included 221 patients with TS enrolled in a multicentric registry. HR at admission was evaluated on the first electrocardiogram. According to tertile distribution of HR at presentation, 3 groups were identified: Group A (HR ≤ 76 beats per minute (bpm), n = 76), Group B (HR 77-95 bpm, n = 74) and Group C (HR 95 bpm, n = 71). Acute in-hospital complications were defined as occurrence of severe pump failure and major arrhythmias.32 (14.4%) patients experienced complicated in-hospital course. HR on admission was significantly higher (108 bpm vs. 85 bpm; p 0.001) and ejection fraction (EF) lower (35% vs. 40%; p = 0.009) in patients with complications than in those without. Patients in Group C experienced a 5-fold higher rate of complications compared to group A and B. After multivariate analysis, higher HR (odds ratio 1.34 per 10 bpm increase, 95% confidence interval (CI) 1.12-1.59; p = 0.001) and lower EF (odds ratio 1.24 per 5% decrease, 95% CI 1.01-1.54; p = 0.049) remained independently associated with a worse outcome.In a large population with TS, high HR on admission independently predicted complicated in-hospital course.

Background Research investigating takotsubo syndrome (TTS) recurrence yielded conflicting results. Aim of the present study is to describe clinical characteristics of patients with TTS recurrence in a cohort with available long-term follow-up. Methods The study population included 234 TTS patients enrolled in a prospective multicenter registry, median follow-up of 1328 (407, 2526) days. To investigate factors associated with TTS recurrence, we analyzed patients with recurrence (Group A) in comparison with a subgroup of TTS patients within the whole population (group B) who had similar age, sex and median follow-up length (Group A 2280 days vs Group B 2361 days). Results We observed 9 TTS recurrences affecting 8 patients, all women, with a rate of 0.9% patients/year. Median time to first recurrence was 1593 days (interquartile range: 950, 2516). We detected no significant differences between patients with and without recurrences regarding cardiovascular risk factors, symptoms, ECG and echocardiographic findings at presentation, discharge therapy. Physical trigger and chronic obstructive pulmonary disease (COPD) were more prevalent in patients who experienced a recurrence (75% vs 27% and 50% vs 14% with p = 0.01 and p = 0.022 respectively). Univariable Cox regression analysis identified physical trigger and history of COPD to be both associated with TTS recurrence [hazard ratio (HR) 11.4, 95% confidence interval (CI) 2.29–56.8, p = 0.003 and HR 4.94, 95% CI 1.16–20.99 p = 0.031 respectively]. Conclusion TTS recurrence is relatively uncommon. Association with physical trigger and COPD would suggest a closer follow-up in this subgroup of patients.

CA extern - Weitere Nicht-UDE-Autoren sind nicht genannt. Aim: The SAMe-TT2R2 score helps identify patients with atrial fibrillation (AF) likely to have poor anticoagulation control during anticoagulation with vitamin K antagonists (VKA) and those with scores >2 might be better managed with a target-specific oral anticoagulant (NOAC). We hypothesized that in clinical practice, VKAs may be prescribed less frequently to patients with AF and SAMe-TT2R2 scores >2 than to patients with lower scores. Methods and results: We analyzed the Phase III dataset of the Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF), a large, global, prospective global registry of patients with newly diagnosed AF and ≥1 stroke risk factor. We compared baseline clinical characteristics and antithrombotic prescriptions to determine the probability of the VKA prescription among anticoagulated patients with the baseline SAMe-TT2R2 score >2 and ≤ 2. Among 17,465 anticoagulated patients with AF, 4,828 (27.6%) patients were prescribed VKA and 12,637 (72.4%) patients an NOAC: 11,884 (68.0%) patients had SAMe-TT2R2 scores 0-2 and 5,581 (32.0%) patients had scores >2. The proportion of patients prescribed VKA was 28.0% among patients with SAMe-TT2R2 scores >2 and 27.5% in those with scores ≤2. Conclusions: The lack of a clear association between the SAMe-TT2R2 score and anticoagulant selection may be attributed to the relative efficacy and safety profiles between NOACs and VKAs as well as to the absence of trial evidence that an SAMe-TT2R2-guided strategy for the selection of the type of anticoagulation in NVAF patients has an impact on clinical outcomes of efficacy and safety. The latter hypothesis is currently being tested in a randomized controlled trial. Clinical trial registration: URL: https://www.clinicaltrials.gov//Unique identifier: NCT01937377, NCT01468701, and NCT01671007. © 2020 Hellenic Society of Cardiology

Background Myocardial involvement in the course of coronavirus disease 2019 (COVID-19) pneumonia has been reported, though not fully characterized yet. The aim of the present study is to undertake a joint evaluation of hs-Troponin and natriuretic peptides (NP) in patients hospitalized for COVID-19 pneumonia. Methods In this multicenter observational study, we analyzed data from n = 111 patients. Cardiac biomarkers subgroups were identified according to values beyond reference range. Results Increased hs-Troponin and NP were found in 38 and 56% of the cases, respectively. As compared to those with normal cardiac biomarkers, these patients were older, had higher prevalence of cardiovascular diseases (CVD) and had more severe COVID-19 pneumonia by higher CRP and d-dimer and lower PaO2/FIO2. Two-dimensional echocardiography performed in a subset of patients (n = 24) showed significantly reduced left ventricular ejection fraction in patients with elevated NP (p = 0.02), whereas right ventricular systolic function (tricuspid annular plane systolic excursion) was significantly reduced both in patients with high hs-Troponin and NP (p = 0.022 and p = 0.03, respectively). Both hs-Troponin and NP were higher in patients with in-hospital mortality (p = 0.001 and p = 0.002, respectively). On multivariable analysis, independent associations were found of hs-Troponin with age, PaO2/FIO2 and d-dimer (B = 0.419, p = 0.001; B = − 0.212, p = 0.013; and B = 0.179, p = 0.037, respectively) and of NP with age and previous CVD (B = 0.480, p

AIM To define the role of cardiac magnetic resonance (CMR) by analyzing a particular group of patients with suspected acute coronary syndrome (ACS) and normal coronary angiogram. METHODS From January 2009 to December 2015, we examined 220 patients with clinical suspicion of ACS, Troponin elevation [the threshold used to define a positive Troponin T test (TnT) was 0.1 ng/mL] and no significant coronary disease at angiography (the patients were considered to have significant angiographic disease only a 50% stenosis was detected in any of their coronary arteries). The role of CMR with the late gadolinium enhancement was evaluated. RESULTS CMR was performed to 190 patients (86%) of this group which reveals: Myocarditis in 90 patients (47%); apical ballooning (Tako-Tsubo syndrome) in 32 patients (17%); myocardial infarction (MI) in 40 patients (21%) and no clear diagnosis identified by CMR in 28 patients (15%). A comparison with previous studies was also made. Clinical and echocardiographic follow-ups were performed at 12 ± 2 mo and no major adverse cardiac events were revealed. CONCLUSION There is a group of patients with clinical suspicion of ACS displaying normal coronary angiograms. CMR was demonstrated to be a valuable tool in the differential diagnosis evaluation of myocarditis, apical ballooning and MI.

Background: GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic t...

Myocardial bridging (MB) and a long recurrent wraparound left anterior descending artery (wrap-LAD) are coronary anatomic variants that have been recently suggested to be associated with takotsubo syndrome (TS). Until now, coronary artery tortuosity (CAT) has never been investigated in this setting. Our study sought to evaluate the prevalence of the aforementioned anatomic variants in a large population with TS. In this retrospective angiographic study, 109 patients with TS were compared with 109 age- and gender-matched subjects without coronary artery disease, valve heart disease, or cardiomyopathy. CAT was identified by ≥3 consecutive curvatures ≥90° (criteria 1) or by ≥2 consecutive curvatures ≥180° (criteria 2). Wrap-LAD was defined if any part of the vessel outreached the apex of the left ventricle and MB as the presence of a milking effect or a step-up and step-down phenomenon. An anatomic variant was found in 79 patients with TS (72%) and in 48 controls (44%) (p0.001). CAT in at least 1 vessel (criteria 1: 49% vs 20%, p0.001; criteria 2: 38% vs 13%, p0.001), ≥2 vessels (criteria 2: 14% vs 3%, p = 0.005), and wrap-LAD (41% vs 27%, p = 0.02) were significantly more frequent in patients with TS than in controls. The prevalence of MB (9% vs 5%, p = 0.18) did not differ between groups. In conclusion, CAT and wrap-LAD have higher prevalence in patients with TS than in matched controls. These findings could support the hypothesis that anatomic variants might act as potential pathogenic substrates in TS.

Functional mitral regurgitation (FMR) is a common finding in patients with ischemic or nonischemic dilated cardiomyopathy as a complication of left ventricular (LV) dysfunction and remodeling associated with a fibrotic remodeling response of mitral leaflets to abnormal valvular loading. Although mitral valve tenting is the main determinant of FMR, clinical and experimental observations suggest that intraventricular delay could be a potential co-determinant of FMR. LV dyssynchrony can potentially contribute to FMR by several mechanisms, such as creating an uncoordinated regional LV mechanical activation in segments supporting the papillary muscles, determining diastolic mitral regurgitation, reducing the sphincteric function of the mitral annulus, and decreasing the efficiency of LV contraction and closing forces. Cardiac resynchronization therapy has been demonstrated to reduce FMR with correction of some of the underlying pathophysiological mechanisms. The present review article focuses on the role of mechanical dyssynchrony as a pathophysiological determinant of FMR, and on the potential role of cardiac resynchronization therapy as a therapeutic option for treatment of FMR in patients with severe heart failure and advanced LV dysfunction.

Cardiac resynchronization therapy (CRT) has been proposed as an alternative treatment in patients with severe, drug-refractory heart failure. The clinical results are promising, and improvement in symptoms, exercise capacity, and systolic left ventricular (LV) function have been demonstrated after CRT, accompanied by a reduction in hospitalization and a superior survival as compared with optimized medical therapy alone. However, 20% to 30% of patients do not respond to CRT. Currently, patients are selected mainly on electrocardiogram criteria (wide QRS complex, left bundle branch block configuration). In view of the 20% to 30% of nonresponders, additional selection criteria are needed. Echocardiography (and, in particular, tissue Doppler imaging) may allow further identification of potential responders to CRT, based on assessment of inter- and intraventricular dyssynchrony. In addition, echocardiography may allow optimal LV lead positioning and follow-up after CRT. In the current review, the different echocardiographic approaches to predict response to CRT are discussed. In addition, the use of echocardiography to guide LV lead positioning and follow-up after CRT are addressed.

Background: In patients with biventricular pacing (BIV), triple-site pacing (TSP), i.e. standard biventricular cathodal pacing of the right and the left ventricle plus additional anodal capture of the right ventricle, is sometimes present. Aims: To evaluate the incidence of TSP phenomenon, to examine TSP-related QRS changes, and to assess the effect of TSP on intraventricular resynchronization by means of tissue Doppler imaging (TDI). Methods and results: 23 patients with a first generation biventricular device (Medtronic 8040) and 16 patients with a new generation device (Medtronic 8042) were evaluated to look for the presence of TSP. TSP was found in 6 patients (26%) with the Medtronic 8040 (group I) and in 13 patients (81%) with the Medtronic 8042 device (group II). QRS duration decreased by 10 to 20 ms and QRS amplitude of leads I and aVL increased in almost all patients in group I during TSP modality. In group II, QRS morphology, duration and amplitude did not change as obviously. TDI analysis of the left ventricular (LV) basal segments showed significant shortening of the systole, together with a corresponding prolongation of the diastole, at the inferior wall of the LV, during TSP compared to standard BIV in all patients (p < 0.01). Other LV segments did not show any change. Qualitative TDI electro-mechanical activation pattern of all LV segments improved in 22%, while it remained unchanged in 72%. Conclusions: TSP phenomenon can be identified in approximately a quarter of patients with the first-generation biventricular devices on the basis of the QRS morphology changes. In the second-generation biventricular pacemakers it can be demonstrated in the vast majority of patients. TSP may increase the effectiveness of cardiac resynchronization therapy by counteracting the regional activation delay located at the inferior wall of the LV.

Cardiac resynchronization therapy is a novel nonpharmacologic approach to treating patients who have advanced heart failure with left bundle branch block (LBBB). Such a therapy is based on the original theory that synchronous biventricular pacing is able to reduce the interventricular delay caused by LBBB in patients with heart failure. Although there is convincing evidence that biventricular pacing increases the left ventricular ejection fraction, decreases mitral regurgitation, and improves symptoms caused by heart failure, the percentage of nonresponders to such therapy has been described as high as about one third of patients with heart failure having LBBB. Factors responsible for this relatively high prevalence are reviewed, the most important of them probably being left intraventricular dyssynchrony, which can persist after biventricular pacing, notwithstanding right and left interventricular resynchronization. Such a dyssynchrony, as evaluated by tissue Doppler imaging, may be because of the discordance between the site of the left ventricular pacing and the site of the left ventricular delay. Therefore, to characterize the pathophysiologic pattern of LBBB, the investigators suggest an assessment of the electromechanical dysfunction with a noninvasive reliable technique, such as tissue Doppler imaging, which can be repeated after biventricular pacing.

Objectives The goal of this study was to compare the efficacy of biventricular pacing (BIV) at the most delayed wall of the left ventricle (LV) and at other LV walls. Background Biventricular pacing could provide additional benefit when it is applied at the most delayed site. Methods In 31 patients with advanced nonischemic heart failure, the activation delay was defined, in blind before BIV, by regional noninvasive Tissue Doppler Imaging as the time interval between the end of the A-wave (C point) and the beginning of the E-wave (O point) from the basal level of each wall. The left pacing site was considered concordant with the most delayed site when the lead was inserted at the wall with the greatest regional interval between C and O points (COR). After BIV, patients were divided into group A (13/31) (i.e., paced at the most delayed site) and group B (18/31) (i.e., paced at any other site). Results After BIV, in all patients LV end-diastolic (LVEDV) and end-systolic (LVESV) volumes decreased (p = 0.025 and 0.001), LV ejection fraction (LVEF) increased (p = 0.002), QRS narrowed (p = 0.000), New York Heart Association class decreased (p = 0.006), 6-min walked distance (WD) increased (p = 0.046), the interval between closure and opening of mitral valve (CO) and isovolumic contraction time (ICT) decreased (p = 0.001 and 0.000), diastolic time (EA) and Q-P2interval increased (p = 0.003 and 0.000), while Q-A2interval and mean performance index (MPI) did not change. Group A showed greater improvement over group B in LVESV (p = 0.04), LVEF (p = 0.04), bicycle stress testing work (p = 0.03) and time (p = 0.08) capacity, CO (p = 0.04) and ICT (p = 0.02). Conclusions After BIV, LV performance improved significantly in all patients; however, the greatest improvement was found in patients paced at the most delayed site.

48 patients (40 Male), mean age 68 ± 8 years, in III–IV class, with intraventricular conduction delay, received a biventricular pacemaker. Heart failure aetiology was non-ischemic in 60%. Left ventricular lead positioning was inferior in 5 patients (10%), posterior in 12 (25%), lateral in 18 (37%) and anterior in 13 (27%). QRS duration and axis were evaluated in sinus rhythm, and during right ventricular pacing, left ventricular pacing and biventricular pacing, the last early after implant and late after 8.8 ± 4.3 months. QRS duration (ms) was 154 ± 29 in sinus rhythm, 175 ± 28 during right ventricular pacing, 196 ± 31 during left ventricular pacing, 122 ± 23 during biventricular pacing “early” and 120 ± 18 during biventricular pacing “late.” All the differences were statistically significant, but not between “early” and “late” biventricular pacing. Mean QRS axis (°) was −27 ± 32 in sinus rhythm, −75 ± 4 during right ventricular pacing, 112 ± 41 during left ventricular pacing, −82 ± 51 during biventricular pacing “early” and −80 ± 42 during biventricular pacing “late.” Only the difference between left ventricular pacing and all the other groups was statistically significant. QRS axis did not significantly differ according to left ventricular lead site during left and biventricular pacing. “Late” compared with “early” biventricular pacing axis showed variation >30° in 35% of patients, in spite of no significant changes in QRS duration and x-ray positioning. Conclusion: Biventricular pacing significantly reduced QRS width, which persisted long-term. Left and biventricular pacing axis was poorly related to left ventricular lead positioning. Biventricular pacing axis variability over time may suggest a role of electrical remodeling.

The aims of the study were, first, to assess whether myocardial ultrasound tissue characterization (UTC) in Becker muscular dystrophy (BMD) can be used to differentiate between patients with deletions and those without deletions; and second, to determine whether UTC is helpful in diagnosing the evolution of left ventricular dysfunction, a precursor of dilated cardiomyopathy. Both cyclic variation of integrated backscatter and calibrated integrated backscatter (cIBS) were assessed in 87 patients with BMD and 70 controls. The average follow-up in BMD patients was 48 ± 12 mo. UTC analysis was repeated only in a subgroup of 40 BMD patients randomly selected from the larger overall group (15 with and 25 without left ventricular dysfunction). Discrimination between BMD patients with and without dystrophin gene deletion was not possible on the basis of UTC data: average cvIBS was 5.2 ± 1.2 and 5.5 ± 1.4 dB, and average cIBS was 29.9 ± 4.7 and 29.6 ± 5.8, respectively, significantly different (p < 0.001) only from controls (8.6 ± 0.5 and 24.6 ± 1.2 dB). In patients developing left ventricular dysfunction during follow-up, cIBS increased to 31.3 ± 5.4 dB, but not significantly (p = 0.08). The highest cIBS values (34.6 ± 5.3 dB, p < 0.09 vs. baseline, p < 0.01 vs BMD patients without left ventricular dysfunction) were seen in the presence of severe left ventricular dysfunction. Multivariate statistics indicated that an absolute change of 6 dB in cIBS is associated with a high probability of left ventricular dysfunction. UTC analysis does not differentiate BMD patients with or without dystrophin gene deletion, but may be useful in indexing left ventricular dysfunction during follow-up.

Background This study was designed to assess whether cardiovascular magnetic resonance imaging (CMR) in Duchenne muscular dystrophy carriers (DMDc) may index any cell milieu elements of LV dysfunction and whether this cardiac phenotype may be related to genotype. The null hypothesis was that myocardial fibrosis, assessed by late gadolinium enhancement (LGE), might be similarly accounted for in DMDc and gender and age-matched controls. Methods Thirty DMDc patients had CMR and genotyping with 37 gender and age-matched controls. Systolic and diastolic LV function was assessed by 2D-echocardiography. Results Absolute and percent LGE were higher in muscular symptomatic (sym) than asymptomatic (asy) DMDc (1.77 ± 0.27 vs 0.76 ± 0.17 ml; F = 19.6, p

Background In patients with heart failure, biventricular pacing (BIV) improves left ventricular (LV) performance by counteracting LV unsynchronized contraction caused by the presence of left bundle branch block (LBBB). However, no data are yet available on regional long-axis function in patients with LBBB or on BIV effectiveness in improving such a function in patients with heart failure and LBBB. Methods and Results We studied with standard 2D echocardiography and tissue Doppler imaging (TDI) 21 nonischemic patients in New York Heart Association (NYHA) class III-IV, with LBBB and QRS ≥120 ms, receiving BIV. To assess long-axis function, TDI qualitative analysis at the basal level of each LV wall was performed in M-mode color and pulsed wave Doppler modalities before and after BIV. By analysis of the interventricular septum, the inferior, posterior, lateral, and anterior walls, of 105 basal segments, the following electromechanical patterns were identified: normal (pattern I), mildly unsynchronized (pattern IIA), severely unsynchronized (pattern IIB), reversed early in systole (pattern IIIA), reversed late in systole (pattern IIIB), and reversed throughout all the systole (pattern IV). After BIV, (1) 49 (46.7%) of 105 segments showed unsynchronized contraction of the same degree as before; (2) 36 (34.3%) of 105 and 20 (19%) of 105 showed unsynchronized contraction of lesser and greater degree, respectively, than before; and (3) a preexcitation pattern was found in 11 (10.5%) of 105, but no segment with pattern IV was observed. According to TDI analysis, patients were divided into group 1 (10 of 21), with less severe LV asynchrony than before BIV, and group 2 (11 of 21), with no change or more severe LV asynchrony than before BIV. In group 1, (1) the LV ejection fraction increased significantly ( P =.01); (2) the exercise tolerance, expressed as time and work capacity on the bicycle stress testing, increased significantly ( P =.01, P =.003, respectively); (3) the 6-minute walked distance increased significantly ( P =.01); and (4) the NYHA class decreased significantly ( P =.003). In group 2, no significant differences were found either in LV ejection fraction, in NYHA class, or in exercise tolerance data ( P = not significant for all). Conversely, the QRS narrowing was significant in both groups ( P =.003 in group 1 and P =.01 in group 2). Conclusions TDI is useful in assessing the severity of LV asynchrony in patients with LBBB with heart failure as well as in evaluating the pacing effects on long-axis function in these patients. BIV reduced unsynchronized and/or dyskinetic contraction in at least one third of the LV basal segments, whereas it induced preexcitation in approximately 10%. Such changes were responsible for better LV synchrony in approximately one half of patients. After BIV, LV performance improved significantly in patients with better LV synchrony evaluated by TDI, whereas the QRS narrowing was not predictive of this functional improvement. (Am Heart J 2001;142:881-96.)

Heart failure is associated with poor long term survival due to progressive refractory heart dysfunction and sudden cardiac death. Cardiac resynchronization through atrio-biventricular pacing has been introduced to treat patients affected by drug-refractory heart failure with desynchronized ventricular activation, as for complete left bundle branch block. The technique is aimed to overcome interventricular and intraventricular conduction delays leading to ventricular dysynchrony, paradoxical septal wall motion, presystolic mitral regurgitation and reduced diastolic filling times. Short term studies demonstrated that biventricular pacing (and perhaps left ventricular pacing alone) may improve both systolic and diastolic function. Initial studies in patients receiving long term pacing consistently showed significant QRS shortening associated with improvement in symptoms, left ventricular ejection fraction, exercise tolerance, quality of life and New York Heart Association functional class. As far as sudden cardiac death prevention in heart failure is concerned, implantable cardioverter defibrillator (ICD) implantation has been demonstrated to be the most effective therapy in patients with prior cardiac arrest due to ventricular fibrillation or poorly tolerated ventricular tachycardia. Low left ventricular ejection fraction, unsustained ventricular tachycardia and inducibility at electrophysiological study also may identify high risk patients requiring ICD implantation. Further studies are needed to evaluate the effect of cardiac resynchronization on hard end-points, such as survival and long term clinical outcome, and to upgrade risk stratification criteria to be used in selection of candidates for ICD implantation.

Aims: To assess the prevalence of anemia and iron deficiency anemia in heart failure (HF) patients, to evaluate the effectiveness of current iron deficiency treatment strategies after discharge, and to analyze hospital readmissions and mortality rates in patients with and without anemia. Patients & methods: A patient registry-based, multicenter, retrospective, observational, cohort study of 418 hospitalized HF patients in Italy, monitored from 1 March 2010 to 30 March 2011. Results: Among patients with HF, 35.9% had anemia at admission; only 51.3% were treated with current iron deficiency treatment strategies during hospitalization and then only 29% of patients who were anemic at discharge were treated with iron at home. After a 4-week follow-up, only 11% of these patients reached the hemoglobin target value (study primary end point). However, current iron deficiency treatment strategies were not significantly associated with reduced risk of rehospitalization, but with a significantly reduced mortality rate after a 6-month follow-up (study secondary end points: 11.7 vs 51.7%; p < 0.0001). Conclusion: In HF patients, there is poor attention paid to anemia, its causes and treatment. Current iron deficiency treatment strategies are mismanaged and CARMES-1 demonstrated that they appear to be insufficient at improving patient outcome in terms of rehospitalization rate reduction, generating high costs, which could be avoided through an optimized treatment strategy. Therefore, more efficacious, efficient and cost–effective treatment strategies are required in Italy for HF patients with iron deficiency anemia to meet this unmet medical need.

The implantable cardioverter defibrillator (ICD) is the treatment of choice for life-threatening arrhythmias. Usually, the device is placed, by a subclavian access, on the upper portion of the pectoralis major muscle. As a result, the visibility of the device and the wide subclavian scar create an important aesthetic deformity, especially in young women, evolving in a relevant psychosocial distress. The authors report their experience with subpectoral ICD implantation. Between January 2001 and December 2011, approximately 30 consecutive female patients underwent submuscular ICD implantation or substitution, performed in collaboration with the cardiology team. No significant complications, except 1 case of wound dehiscence and 2 cases of caudal dislocation of the device, were observed. At 6 and 12 months' follow-up, no significant difference between preoperative and postoperative breast symmetry and volume was noticed. The combined approach aims at reducing the visible signs of the procedure and improving the psychological outcomes.

Objectives The present study attempts to identify appropriate elements that may contribute to clarify the broad clinical features (diagnosis, care, complication and prognosis) of Takotsubo-like cardiomyopathy for improving its management. Design study Observational study. Setting Primary level of care referred to the emergency department of Vannini Hospital, Rome, Italy. Participants The study population consisted of 75 patients, 72 of the them were women and 3 were men with a mean age of 71.9±9.6 years. Methods From February 2004 to November 2010, prospectively included 84 consecutive patients diagnosed for suspected Takotsubo-like cardiomyopathy. To be eligible, patients had to meet all the Mayo clinic criteria in the absence of neurological trauma or intracranial haemorrhage. Moreover, those patients that at follow-up still presented alteration of acute phase at ECG and echocardiogram were excluded. Thus, 75 patients comprised the study population. To follow-up 19 patients were lost. Results None of 75 patients died in acute phase. All patients were promptly discharged (8.4±4.4 days), since they recovered their normal functional status without symptoms. Follow-up information was available for 56 patients. At a mean follow-up time of 2.2±2 years (range, 0.1–6.8 years) two octogenarian patients (2.6%) died because of sudden cardiac death and pulmonary embolism, respectively. The Takotsubo-like cardiomyopathy recurred in one patient. Conclusions The results of this study support the previous reports about the good prognosis, also in critically ill patients, of Takotsubo-like cardiomyopathy. Further assessment will be needed to determine a careful and sustained follow-up for choosing the best care and foreseeing the recurrences of this emerging condition.

International audience; BACKGROUND: Biventricular (BiV) stimulation is the preferred means of delivering cardiac resynchronization therapy (CRT), although left ventricular (LV)-only stimulation might be as safe and effective. B-LEFT HF is a prospective, multicenter, randomized, double-blind study aimed to examine whether LV-only is noninferior to BiV pacing regarding clinical and echocardiographic responses. METHODS: B-LEFT HF randomly assigned 176 CRT-D recipients, in New York Heart Association class III or IV, with an LV ejection fraction < or =35% and QRS > or =130 milliseconds, to a BiV (n = 90) versus LV (n = 86) stimulation group. Clinical status and echocardiograms were analyzed at baseline and 6 months after CRT-D implant to test the noninferiority of LV-only compared with BiV stimulation. RESULTS: The proportion of responders was in line with current literature on CRT, with improvement in heart failure composite score in 76.2% and 74.7% of patients in BiV and LV groups, respectively. Comparing LV versus BiV pacing, the small differences in response rates and corresponding 95% CI indicated that LV pacing was noninferior to BiV pacing for a series of response criteria (combination of improvement in New York Heart Association and reverse remodeling, improvement in heart failure composite score, reduction in LV end-systolic volume of at least 10%), both at intention-to-treat and at per-protocol analysis. CONCLUSIONS: Left ventricular-only pacing is noninferior to BiV pacing in a 6-month follow-up with regard to clinical and echocardiographic responses. Left ventricular pacing may be considered as a clinical alternative option to BiV pacing.

The purpose of the study is to evaluate the feasibility and utility of magnetic resonance (MR) image and electroanatomic (EA) maps integration in guiding detailed left ventricle (LV) anatomical and substrate mapping, identifying the most accurate registration strategy. Twenty-five patients with dilated ischemic or non-ischemic cardiomyopathy were enrolled. We first verified the feasibility and accuracy of EA mapping and MR image integration using four different strategies (15 patients). Different EA maps were performed according to the strategy in exam: aortic map, collected from the descending portion of the arch to the ascending one; partial or complete LV map, reconstructed with a minimum of 40 widely distributed points or 200 points, respectively. We then evaluated the utility in LV substrate mapping of the most accurate integration method identified (ten patients). Strategy III, based on aortic map and a partial LV map, allowed us to obtain an accurate integration with MR images of aorta and LV with a lower number of EA LV points; we therefore used this strategy during phase II of the study. Both mean LV end diastolic volume and long- and short-axis LV end diastolic diameters obtained by MR were not significantly different compared with Carto measurements. Eighty-eight percent of the segments with transmural/subendocardial scar detected by delayed enhanced MR were localized on bipolar voltage maps projected on MR-integrated images. This study shows that integration strategy III represents the optimal registration method. Its clinical utility consists on guiding the catheter roving inside the chamber, mapping all areas of the LV and optimizing scar reconstruction.

Stress cardiomyopathy is a reversible left ventricular dysfunction triggered by emotional stress. We describe a variant of transient left ventricular ballooning in a patient in which basal and midventricular segments are affected. This confirms that there is not just one ventricular dysfunction pattern in Takotsubo cardiomyopathy. The involvement of only the basal and midventricle segments is an intriguing observation with no clear explanation; furthermore, there are no predictive factors for the differently sited wall motion abnormalities.

Myocarditis is difficult to recognize in the early phase particularly when it mimics acute myocardial infarction (STEMI). New strategies to diagnose active myocarditis are needed to avoid unnecessary coronary angiography in such an acute setting. Contrast-enhanced magnetic resonance imaging (MRI) is able to discriminate the small myocardial injuries due to myocarditis from the segmental lesions of ischemic origin.

Aortic valve stenosis is a common disease. Despite this, the diagnosis may often be missed; a significant proportion of patients are still identified at post-mortem examination, and 5% of operations are performed at end stage. Unrecognized aortic valve stenosis is an important cause of anesthetic mortality. One reason for failing to make a diagnosis is that the clinical signs can be difficult to interpret due to the confounding association with arterial hypertension, coronary artery disease and systemic arteriosclerosis, potentially blunting the effects of aortic valve stenosis on the circulation. Moreover, most patients with aortic valve stenosis have a long asymptomatic period and may not seek medical attention. In patients with severe, symptomatic, calcific aortic valve stenosis, aortic valve replacement is the only effective treatment; much evidence suggests that it should be offered to patients regardless of age, after appropriate clinical evaluation. Doppler echocardiography plays a pivotal role in confirming the diagnosis of aortic valve stenosis in assessing the severity of the disease and, ultimately, in giving prognostically relevant information. Moreover, echocardiography is suitable for monitoring of disease progression and left ventricular function in these patients, and is of fundamental support for clinical follow-up. Accurate noninvasive quantification of aortic valve stenosis is, however, a technically demanding and time-consuming procedure, with several potential pitfalls. Considering the frequency and importance of aortic valve stenosis, a comprehensive echocardiographic study should be offered and carefully performed in all patients with noteworthy murmurs and repeated regularly (at appropriate time intervals), together with clinical review, in patients in whom aortic valve stenosis has been diagnosed.

The aim of our study was to evaluate the efficacy of magnetic resonance imaging (MRI) in the differential diagnosis between active myocarditis and myocardial infarction in patients with clinical symptoms mimicking acute myocardial infarction. Between 1 January 2006 and 30 June 2007, 23 consecutive patients (21 men and 2 women) presenting with electrocardiographic abnormalities mimicking acute myocardial infarction and a clinical suspicion of acute myocarditis (fever, chest pain and elevated troponin levels) underwent contrast-enhanced cardiac MRI within a week of admission. All patients also underwent coronary angiography, which demonstrated the absence of significant coronary artery lesions. The mean follow-up period was 2±4 months. Cardiac MRI with injection of contrast material showed late subepicardial and intramyocardial enhancement in all patients. Subendocardial late enhancement, a typical pattern of myocardial infarction, was never seen. In addition, in agreement with the literature, there was prevalent involvement of the lateral segments of the left ventricular wall. Cardiac MRI could be a valuable tool for the early diagnosis of acute myocarditis, as it can demonstrate specific patterns that help rule out acute myocardial infarction.

A large population of sick sinus syndrome (SSS) patients was analyzed to determine whether age of patients, presence of conduction disturbances and mode of permanent pacing are related to the occurrence of supraventricular tachyarrhythmias, cerebral embolism and cardiac mortality. Three hundred thirty-nine patients permanently paced (135 AAI, 79 DDD, 125 VVI) because of SSS were followed for a mean period of 5 years (range 2 to 10). Patients were divided into 4 groups according to age ( 70 years) and the presence or absence of an associated conduction disturbance. Sixty-eight percent of VVI, 55% of AAI and 40.5% of DDD patients were > 70 years of age. In the VVI and DDD groups a conduction disturbance was present in 67 of 204 (33%) patients; conduction disturbances were more common in patients > 70 years old (46 of 111, 41%) than in those 140 beats/min) remained unchanged during the follow-up period in 82% of AAI patients. In 9% of these patients, the Wenckebach threshold showed some degree of deterioration, but only in 2 patients was it Spontaneous second-degree atrioventricular block was observed in 7 patients (5%); it disappeared in 6 of these patients when drug therapy was discontinued. The incidence of atrial fibrillation was higher in the VVI group (47%) than in the DDD (13%, p A higher incidence of stable atrial fibrillation in the VVI group was also observed, regardless of age or conduction disturbance. Overall mortality rates were 30% in VVI, 16% in DDD and 13% in the AAI mode (p 70 years old (15%) than in the DDD group > 70 years (p > 0.03). The presence of conduction disturbance did not influence cardiac mortality. The stroke mortality rates were 8% in the VVI, 2% in the AAI and 2.5% in the DDD group (difference not significant). The difference in stroke mortality became statistically significant in the subgroup of patients > 70 years old between the VVI (17%) and AAI (3%) modes (p Our data indicate that the AAI and DDD modes should always be preferred to the VVI mode in treatment of SSS, particularly in patients > 70 years of age.

OBJECTIVE Clinical recognition of acute myocarditis is difficult. Late enhancement (LE) detected by magnetic resonance imaging appears to be a valuable tool for evaluating and monitoring inflammatory myocardial diseases. However, patterns of myocardial enhancement and its correlation with systolic function are not yet well defined. The aim of this study was to assess the extent and location of LE during the acute phase of active myocarditis mimicking acute myocardial infarction and at follow-up, in order to correlate LE with systolic function and to monitor disease progression. METHODS Magnetic resonance imaging was performed in 13 patients with clinical symptoms and signs of acute myocarditis. RESULTS All patients showed LE, which was located in the lateral free wall in 11 (85%) patients, at the basal level in eight (61%), at the mid level in nine (69%), and at the distal level in 10 (77%). Moreover, six (46%) patients showed LE in the posterior and inferior wall (P = 0.099 versus lateral wall), four (31%) patients in the septum and inferior wall (P = 0.017 versus lateral wall) and three (23%) patients in the anterior wall (P = 0.006 versus lateral wall). Left ventricular ejection fraction was 0.50 +/- 10 and it was severely reduced only in one patient (0.20). Conversely, in the remaining patients, left ventricular ejection fraction was preserved (> or =0.45) (P < 0.001). Multifocal LE was detected in eight (61%) patients, whereas pericardial effusion was observed only in two (15%) patients (P = 0.002). Twelve patients showed ST-segment elevation and chest pain, as it occurs in acute myocardial infarction, whereas one patient showed non-ST-segment elevation with dyspnoea, as it occurs in non-ST-elevation myocardial infarction. The mean follow-up duration was 4 +/- 12 months, and follow-up was complete for all but one patient who died. LE extent decreased in 11 (92%) patients, whereas new areas of LE were detected in one (8%) patient (P < 0.001). CONCLUSIONS Contrast enhancement is a frequent finding in the clinical setting of suspected myocarditis and is associated with active and/or persistent myocardial inflammation. Myocarditis detected by magnetic resonance imaging predominantly occurs in the lateral free wall and very rarely affects systolic function.

Stress cardiomyopathy is a reversible left ventricular dysfunction precipitated by emotional stress. Affected patients are generally women, whose symptoms are similar to myocardial infarction with reversible apical dyskinesis associated with hypercontractile basal segments and no evidence for hemodynamically significant coronary arterial stenoses by angiography. We report the case of an 82-year-old woman who presented with acute onset of chest pain after emotional stress and with reversible left ventricular dysfunction consisting of akinesis of the midventricular segments and hyperkinesis of the basal and apical segments.

Doppler echocardiography is a fundamental instrument to understand heart damage during essential arterial hypertension. Left ventricular (LV) hypertrophy may also be conveniently studied in its morphological and functional aspects by ultrasound application. Echocardiography can also provide important morphological and functional information in hypertensive patients for therapeutic management and prognostic stratification. In recent years, echocardiography has been enriched by very refined techniques that are capable of studying the physiopathological intramyocardial phenomena: (i) tissue Doppler (which studies intramyocardial velocities and time intervals and allows the analysis of strain and strain rate); (ii) integrated backscatter (which analyzes variations of myocardial reflectivity in decibels); (iii) transthoracic Doppler derived coronary flow reserve (which quantifies the vasodilator response of coronary velocities to a hyperaemic stimulation); (iv) myocardial echo-contrast-echocardiography (which studies the kinetics of ultrasound contrast microbubbles at the intramyocardial level); and (v) real-time three-dimensional (3-D) echocardiography [which allows a more precise evaluation of left ventricular (LV) volumes and LV mass]. These new methodological approaches have recently been used in the hypertensive clinical setting to provide a deeper knowledge of the complex physiopathological and histopathological mechanisms underlying the modifications induced by arterial hypertension at the myocardial tissue level (myocytes, collagen, microcirculation). This review shows the advancement of high-tech ultrasound applied to hypertensive heart disease, pointing out limitations and incremental potentialities in comparison with conventional echocardiography.

Chronic heart failure (HF) is recognized as an important public health problem but little attention has been focused on acute-stage HF.Nationwide, prospective, observational study setting 206 cardiology centres with intensive cardiac care units. During 3 months, 2807 patients diagnosed as having de novo acute HF (44%) or worsening chronic HF (56%) were enrolled. Acute pulmonary oedema was the presenting clinical feature in 49.6% of patients, cardiogenic shock in 7.7%, and worsened NYHA functional class in 42.7% of cases. Anaemia (Hb12 g/dL) was present in 46% of patients, renal dysfunction (creatinineor =1.5 mg%) in 47%, and hyponatraemia (or =136 mEq/L) in 45%. An ejection fraction (EF)40% was found in 34% of cases. Intravenous diuretics, nitrates, and inotropes were given to 95, 51, and 25% of patients, respectively. The median duration of hospital stay was 9 days. In-hospital mortality rate was 7.3%. Older age, use of inotropic drugs, elevated troponin, hyponatraemia, anaemia, and elevated blood urea nitrogen were independent predictors of all-cause death; prior revascularization procedures and elevated blood pressure were indicators of a better outcome. The rehospitalization rate within 6 months was 38.1%, all-cause mortality from discharge to 6 months was 12.8%.Acute HF is an ominous condition, needing more research activity and resources.

Aims Cardiac resynchronization therapy (CRT) confers sustained therapeutic benefits to patients suffering from congestive heart failure (CHF) due to systolic dysfunction associated with ventricular dyssynchrony. Biventricular (BiV) pacing has, thus far, been the preferred method, as it corrects both electrical and mechanical dyssynchrony. Left ventricular (LV) only pacing, which has conferred similar benefits in pilot studies, may be an alternative treatment method. ‘Biventricular vs. left univentricular pacing with ICD back-up in heart failure patients’ (B-LEFT HF) is an international, prospective, randomized, parallel-design, double-blind, clinical trial to examine whether LV only pacing is as safe and effective as BiV pacing in patients suffering from CHF. Methods and results The trial will randomly assign 172 patients to either LV only or BiV pacing. The study has prospectively defined efficacy endpoints to be evaluated at 6 months, which are (i) changes in functional capacity and degree of reverse remodelling (primary) and (ii) changes in the heart failure clinical composite response (secondary). Conclusion Because LV only pacing in CRT is likely to be technically less challenging and costly than BiV, a specifically designed study is needed to compare the safety and effectiveness of the two configurations. B-LEFT HF has been designed to settle this critical issue.

New technologic development of implantable cardioverter-defibrillators (ICDs) keeps up with the exponential increase of their use for primary and secondary prevention of sudden cardiac death. The first-generation ICD with limited shock capability alone could be considered adequate in most cardiac arrest victims, but it was not suitable for sudden death prevention in all high-risk patients with cardiac disease. The second-generation ICD was comprised of hybrid pacemaker-defibrillator systems that provided on-demand ventricular antibradycardia pacing. The third-generation devices include additional functions, such as antitachycardia pacing for ventricular tachycardia (VT) reversion and low-energy ventricular cardioversion, in addition to ventricular defibrillation and single-chamber ventricular demand pacing. In the near future, advanced dual-chamber atrioventricular (AV) pacing and defibrillating systems will also be available. The dual chamber ICD will allow atrial inhibited/dual-chamber (AAI/DDD) rate-responsive pacing, simultaneous atrial and ventricular sensing to optimize the arrhythmia identification, and ICD shock delivery in the proper arrhythmia-related chamber. Clinical benefits of these devices compared with their cost and complexity will require careful evaluation.

Although the superiority of dual-chamber (DDD) pacing in terms of haemodynamic and clinical benefits has well been established compared to single-chamber ventricular (VVI) pacing modality, especially in some conditions such as recurrent atrial tachyarrhythmias and congestive heart failure, much still remains to be done to reach a truly physiological way of pacing the human heart. The optimal pacing system should mimic the native physiological functioning of the conduction system as closely as possible. In reality, current pacing systems are far from reproducing the function of the normal heart. If in some cases clinical benefits can paradoxically be obtained by means of an “unphysiological” pacing (e.g. pacing the right ventricular apex to reduce left intraventricular gradient in obstructive cardiomyopathy), in the vast majority of cases pacing with the current technology and configuration produces detrimental effects on several aspects of cardiac functionality, and does not allow maximal benefits to be obtainedl. The normal sequence of electric activation of the ventricles is largely disrupted by pacing the right ventricular apex; the normal sequence of atrial activation is modified by the current method of pacing in the right atrial appendage causing intra-atrial delays; the optimal temporisation of atrial and ventricular contraction would require atrioventricular (AV) delay adjustments; the current single-sensor technology only in part resembles the physiological sinus node response to metabolic, activity and emotional requirements.

To overcome the limitation of the fixed heart rate of VVI/DDD pacing, devices having a system of sensors able to modify the rate of pulse discharge and to meet the metabolic needs of the patients (DDDR/VVIR pacing) have been tested in several investigations [1–6]. In addition, the superiority of DDDR pacing versus WIR pacing due to the preservation of the a-v synchronism has been proven especially when the atrioventricular (AV) delay is also rate-adaptive [2–6].

Previous studies with pacemaker patients have documented the significant contributions of heart rate and atrioventricular (AV) synchrony to an increase in cardiac output during exercise [1–3]. Several authors have hypothesized that the heart rate is the dominant factor [4–7]. In fact, it is well-known that before the advent of rate-responsive pacing, many patients were limited by fixed rate pacing (VVI) or by minimal increases in heart rate during physical or emotional stress. As comparable hemodynamics can be achieved at maximum exercise through the increase in rate without maintaining AV synchrony [7–11], single chamber ventricular rate-adaptive (WIR) pacing has been advocated alternative approach to dual chamber pacing (DDD).