Echocardiographic assessment of ventricular contraction and synchrony in children with isolated complete atrioventricular block and epicardial pacing: Implications of interventricular mechanical delay

Cardiac resynchronization therapy via left bundle branch pacing in heart failure with complete left bundle branch block: is the defibrillator needed?

Aims

This retrospective cohort study aimed to investigate the efficacy of dual-chamber left Bundle branch pacing (LBBP) as an alternative therapy for heart failure patients with complete left bundle branch block (CLBBB) and indications for defibrillator with cardiac resynchronization therapy (CRT-D).

Methods

34 patients met inclusion criteria were enrolled in the study. These criteria included a left ventricular ejection fraction (LVEF) of lower than 35%, a New York Heart Association functional class of II-IV, CLBBB meeting Strauss's criteria, intraventricular dyssynchrony, and confirmed correction of CLBBB during LBBP. Patients with ischemic cardiomyopathy, left ventricular noncompaction, significant late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR), and indications for an implantable cardioverter-defibrillator (ICD) as secondary prevention were excluded.

Results

Post-LBBP, the LVEF improved from 31.1 ± 4.0% to 61.0 ± 6.0% (P < 0.001). All patients exhibited a super-response to LBBP cardiac resynchronization therapy, achieving complete improvement in cardiac function with a LVEF exceeding 50%. Septal-to-posterior wall motion delay (SPWMD) and systolic dyssynchrony index (SDI) were indicators of intraventricular synchrony, SPWMD decreased from 271.4 ± 76.4 ms to 42.2 ± 22.9 ms (P < 0.001), and SDI decreased from 12.5 ± 5.3% to 1.9 ± 1.0% after implantation (P < 0.001).

Conclusions

Heart failure patients meeting the following criteria may be considered for dual-chamber pacing as an alternative to CRT-D, potentially avoiding the need for ICD implantation: (1) CLBBB meeting Strauss's criteria, (2) presence of intraventricular dyssynchrony on echocardiogram, (3) exclusion of secondary prevention ICD indications, (4) absence of evident LGE on CMR, and (5) successful correction of CLBBB during LBBP.

Analysis of the influencing factors associated with dyssynchrony and cardiac dysfunction in children with ventricular pre-excitation

OBJECTIVE

To investigate the correlation between ventricular pre-excitation-related dyssynchrony, on cardiac dysfunction, and recovery.

METHODS AND RESULTS

This study included 76 children (39 boys and 37 girls) with a median age of 5.25 (2.67-10.75) years. The patients with pre-excitation-related cardiac dysfunction (cardiac dysfunction group, n = 34) had a longer standard deviation of the time-to-peak systolic strain of the left ventricle and larger difference between the maximum and minimum times-to-peak systolic strain than those with a normal cardiac function (normal function group, n = 42) (51.77 ± 24.70 ms versus 33.29 ± 9.48 ms, p < 0.05; 185.82 ± 92.51 ms versus 111.93 ± 34.27 ms, p < 0.05, respectively). The cardiac dysfunction group had a maximum time-to-peak systolic strain at the basal segments of the anterior and posterior septa and the normal function group at the basal segments of anterolateral and posterolateral walls. The prevalence of ventricular septal dyssynchrony in the cardiac dysfunction group was significantly higher than that in the normal function group (94.1% (32/34) versus 7.7% (3/42), p < 0.05). The patients with ventricular septal dyssynchrony (n = 35) had a significantly higher prevalence of intra-left ventricular systolic dyssynchrony than those with ventricular septal synchrony (n = 41) (57.1% (20/35) versus 14.6% (6/41), p < 0.05). During follow-up after pathway ablation, the patients who recovered from intra-left ventricular dyssynchrony (n = 29) had a shorter left ventricular ejection fraction recovery time than those who did not (n = 5) (χ² = 5.94, p < 0.05). Among the patients who recovered, 93.1% (27/29) had a normalised standard deviation of the time-to-peak systolic strain and difference between the maximum and minimum times-to-peak systolic strain within 1 month after ablation.

CONCLUSION

Ventricular pre-excitation may cause ventricular septal dyssynchrony; thus, attention must be paid to intra-left ventricular dyssynchrony and cardiac dysfunction. Whether intra-left ventricular systolic dyssynchrony can resolve within 1 month may be a new early predictor of patient prognosis.

Tricuspid insufficiency after cardiac-implantable electronic device placement

OBJECTIVE

Device-related estimates of incidence and significance of tricuspid regurgitation (TR) is mainly based on case reports and small observational studies. We sought to determine whether right-heart device implantation increased the risk of TR in this interventional study.

METHODS

All patients who underwent permanent pacemaker (PPM) or other device implantation were assessed for degree of TR at one year. The data collected was analyzed on IBM SPSS version 26. Descriptive statistics were applied for qualitative variables. Mean and standard deviation were applied for quantitative variables. Regression analysis and paired t-tests were applied for the degree of change and predictors of TR.

RESULTS

Out of 165 participants, 73.94% were male. The mean age of the participants was 59.86 ± 12.03 years. Dual-chamber pacemaker (DDDR) was the most common device implanted (78.18%) causing significant TR and drop in left ventricular ejection fraction as compared to other devices (p-value < 0.05). The paired t-test for changes in ejection fraction (LVEF) and TR were also significant (p-value < 0.05). A regression model predicted significant TR to depend on baseline LVEF (p-value < 0.05).

CONCLUSION

Device-related worsening of TR is related to mechanical mechanisms. It is significantly associated with DDDR pacemakers after a 1-year follow-up.