Permanent Cardiac Pacing in Children: Choosing the Optimal Pacing Site: A Multicenter Study

Study Questions:

What are the effects of the site of left ventricular (LV) synchrony and function in children requiring permanent pacing?

Methods:

A cross-sectional multicenter study was performed. One hundred seventy-eight children were enrolled from 21 international centers. All patients had structurally normal hearts.

Results:

The median age at evaluation was 11.2 (interquartile range, 6.3-15.0) years. Median duration of pacing was 5.4 (interquartile range, 3.1-8.8) years. Pacing sites included the free wall of the right ventricular (RV) outflow tract (n = 8), lateral RV (n = 44), RV apex (n = 61), RV septum (n = 29), LV apex (n = 12), LV midlateral wall (n = 17), and LV base (n = 7). LV synchrony, ejection fraction, and contraction efficiency were site dependent and were superior in children paced at the LV apex and LV midlateral wall. Pacing from the RV outflow tract and lateral RV predicted significantly decreased LV function, whereas LV apex/LV midlateral wall pacing were associated with preserved LV function. The effect of mechanical asynchrony and contraction inefficiency was most pronounced with RV lateral and RV outflow tract pacing, and less pronounced for RV apical pacing.

Conclusions:

The site of ventricular pacing has a major impact on LV mechanical synchrony, efficiency, and pump function in children who require lifelong pacing. LV apex and lateral LV wall pacing appear to have the most favorable effect, whereas RV outflow tract and lateral RV wall pacing are associated with a high risk of LV dysfunction.

Perspective:

This relative large, multicenter trial assessed pacing sites and their effect on LV function and synchrony in pediatric patients with complete heart block and structurally normal hearts. This is an important group to study, as patients require many years of pacing, and decisions made early in life may have an important impact on long-term LV function. This study demonstrates the superiority of LV pacing when feasible. Importantly, many patients did tolerate traditional RV pacing, particularly when paced in the RV apex. This also adds to the growing body of evidence suggesting that a large part of the benefit of biventricular pacing is pacing of the systemic ventricle.

Clinical Topics: Arrhythmias and Clinical EP, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, Congenital Heart Disease, CHD & Pediatrics and Arrhythmias

Keywords: Child, Atrioventricular Block, Ventricular Function, Right, Heart Defects, Congenital, Ventricular Septum, Cardiac Pacing, Artificial, Pacemaker, Artificial, Heart Ventricles, Cardiac Resynchronization Therapy


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