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Background: The long-term outcomes of patients with congenital and childhood complete atrioventricular block (CCAVB/CAVB) after pacemaker implantation are unclear., Methods: We performed a meta-analysis of all the studies of CCAVB. A systematic search of PubMed and CENTRAL databases from January 1, 1967 to January 31, 2020 was performed. The quality of studies included was critically appraised using the Newcastle-Ottawa scale, and outcome data were analyzed using the restricted maximum likelihood function., Results: Twenty-nine studies were eligible for analysis, with a total of 1553 patients. The all-cause-mortality was 5.7% (95% confidence interval [CI]: 2.5%-9.9%), while pacing-induced cardiomyopathy (PICM) was seen in 3.8% (95% CI: 1.2-7.2). Diagnosis at birth (effect size [ES] [95%CI]: -2.23 [-0.36 to -0.10]; p < .001), presence of congenital heart disease (ES [95%CI]: -0.67 [0.41-0.93]; p < .001), younger age at pacemaker implantation (ES [95%CI]: -0.01 [-0.02 to -0.001]; p = .02), and duration of pacing (ES [95%CI]: -0.03 [-0.05 to -0.003]; p = .03), were associated with an higher mortality on binominal logistic regression. None of the parameters were significant on multivariate analysis., Conclusion: Pooled proportional mortality in patients with CCAVB and CAVB is 5.7% with an infrequent incidence of PICM (3.8%) in the paced patients with AVB suggesting that pacing in these patients is an effective management strategy with a low incidence of long-term side effects. Registry and randomized data can throw additional light regarding the natural history and appropriate management strategy in these patients., (© 2022 Wiley Periodicals LLC.)

Background: There is a high incidence of atrial fibrillation (AF) in patients with isolated rheumatic mitral regurgitation (MR). The histopathologic changes in the atria of patients with isolated rheumatic MR with and without AF are unknown., Objectives: We aimed to determine the histological findings in patients with isolated severe rheumatic MR with and without AF., Methods: Patients with severe isolated rheumatic MR undergoing valve replacement surgeries underwent endocardial biopsies from right atrial appendage, left atrial appendage, right free wall, left free wall, left posterior wall, and mitral valve. Group I consisted of patients in sinus rhythm (SR), and Group II included patients with AF. We analyzed and compared these 10 histological features in the biopsies of patients in Groups I and II., Results: Of the 25 patients, 12 were in Group I and 13 in Group II. In Group I, patients had severe myocyte hypertrophy (60% vs. 18%, p = .04) that was significantly more in the right atrium (22.7% vs. 11.4%, p = .059). Interstitial adipose tissue deposition was more common in Group I (30% vs. 25%, p = .06). Interstitial fibrosis was evenly distributed at all sites without significant difference between the two groups. Group II patients had a higher prevalence and severity of vacuolar degeneration (91% vs. 60%, p = .09)., Conclusions: Patients with isolated severe rheumatic MR and AF have more vacuolar degeneration in the atrial tissue. Patients with SR have myocyte hypertrophy and interstitial adipose tissue deposition. Interstitial fibrosis is uniformly distributed in patients in SR and AF., (© 2021 Wiley Periodicals LLC.)

Introduction: There is a surge of interest in alternate site pacing to prevent pacing-induced left ventricular dysfunction. However, little is known regarding the appropriate atrioventricular (AV) delay between right ventricular (RV) septal and RV apical pacing for optimal hemodynamic benefit., Objectives: To determine the programmed values of atrial sensed and atrial paced AV delays in basal RV septal and apical RV pacing that results in the maximum delivered stroke volume (SV)., Methods: We calculated the Doppler-derived SV at various sensed and paced AV delays in 50 patients with complete AV block implanted with a dual-chamber pacemaker (group A: 25 RV apical pacing; group B: 25 RV septal pacing). The hemodynamic difference in terms of the SV between sensed and paced AV delay, corresponding to the site of RV pacing was then compared for statistical significance., Results: In group A, maximal SV was derived at a sensed AV delay of 123.2 ± 11 ms and paced AV delay of 129.2 ± 10 ms, and in group B, at a sensed AV delay of 123.6 ± 8 ms and paced AV delay of and 132.8 ± 7 ms. At these intervals, there was no difference in the SV between septal and apical RV pacing (P = .28 and .22, respectively)., Conclusion: The atrial sensed and atrial paced AV delays for septal and apical RV pacing for optimal hemodynamics are similar. For optimal hemodynamics, the atrial paced AV delay is longer than the atrial sensed AV delay., (© 2019 Wiley Periodicals, Inc.)

Background: Mitral stenosis (MS) has the highest incidence of atrial fibrillation (AF) in chronic rheumatic valvular disease. There are very few studies in isolated MS comparing histopathological changes in patients with sinus rhythm (SR) and AF., Objectives: To analyze the histological changes associated with isolated MS and compare between changes in AF and SR., Methods: This was a prospective study in patients undergoing valve replacement surgery for symptomatic isolated MS who were divided into 2 groups, Group I AF (n = 13) and Group II SR (n = 10). Intra-operative biopsies performed from 5 different sites from both atria were analyzed for 10 histopathologic changes commonly associated with AF., Results: On multivariate analysis, myocytolysis (odds ratio [OR]: 1.48, P = 0.05) was found to be associated with AF, whereas myocyte hypertrophy (OR: 0.21, P = 0.003), and glycogen deposition (OR: 0.43, P = 0.002) was associated with SR. Interstitial fibrosis the commonest change was uniformly distributed across both atria irrespective of the rhythm., Conclusion: In rheumatic MS, SR is associated with myocyte hypertrophy whereas AF is associated with myocytolysis. Endocardial inflammation is more common in left atrial appendage irrespective of rhythm. Interstitial fibrosis is seen in >90% of patients distributed in both the atria and is independent of the rhythm. Amyloid and Aschoff bodies are uncommon and the rest of the changes are uniformly distributed across both the atria., (© 2016 Wiley Periodicals, Inc.)