Diastolic function in paced children with cardiac defects: septum vs apex

Area of Science:

• Pediatric Cardiology
• Cardiovascular Physiology
• Biomedical Engineering

Background:

• The impact of chronic ventricular pacing on diastolic function in pediatric patients with structural congenital heart disease (CHD) remains unclear.
• The superiority of septal pacing over apical pacing is a subject of ongoing debate.

Purpose of the Study:

• To investigate how different right ventricular (RV) pacing locations affect left ventricular (LV) diastolic function in children with cardiac defects.

Main Methods:

• A prospective study of 29 pediatric patients with complete atrioventricular block (CAVB) and CHD undergoing permanent pacing.
• Patients were divided into two groups: RV apex pacing (n=16) and RV septum pacing (n=13).
• Echocardiographic assessments, including transmitral E-wave and tissue Doppler imaging (TDI) parameters, were performed before and after pacemaker implantation, with a mean follow-up of 4.9 years.

Main Results:

• RV apical pacing significantly affected transmitral E-wave and lateral annular TDI parameters compared to RV septum pacing.
• The E' wave showed an inverse correlation with the TDI lateral myocardial performance index (Tei index) (R²=0.9849, p ≤ 0.001).
• RV apex pacing and elevated TDI lateral Tei index were significant predictors of reduced LV diastolic function.

Conclusions:

• RV septal pacing is superior to RV apical pacing in preventing pacing-induced reductions in LV diastolic function in children with CHD.
• Septal pacing should be considered to optimize diastolic function in pediatric patients requiring permanent ventricular pacing.