Cardiac pacing in cardioinhibitory syncope in children

Reflex vasovagal-or cardioinhibitory syncope is known to be a major cause of recurrent syncope in children. The mechanism of vasovagal syncope (VVS) is an interaction between a vagally mediated bradycardia or asystole and a more or less manifest vasodilatory component. Although pacing is not advisable as a standard approach in patients with VVS, it remains a treatment option of last resort in exceptionally severe cases, or patients with contraindication or refractoriness to drug therapy and life style changes. To effectively avoid VVS in these patients, the pacemaker has to both prevent bradycardia and to compensate for the vasodilatory component. Therefore, this study aimed to evaluate a simple pacemaker setting (VVI pacing with hysteresis) with the potential to prevent VVS in affected children.

Clinical data of patients, who were presented to the Department for Pediatric Cardiology, Heart Center Leipzig, in the period of 2001-2017 for cardiac pacemaker implantation for cardioinhibitory syncope or pallid breath-holding spells, were collected retrospectively.

Eleven pediatric patients, median age 2.7 (0.8-17) years, were included. Pacemaker settings are depicted. In 10 out of 11 patients, an entire abolishment of syncope could be achieved (P = .002).

The presented VVI pacing with hysteresis seems to be a promising pacemaker setting in pediatric patients with cardioinhibitory syncope who need a pacemaker. Unnecessary ventricular stimulation is effectively avoided, while cardiac output is preserved during cardioinhibition, by providing a sufficient paced heart rate, compensating for the often present vasodilatory component.