Modern pacemaker algorithms in paediatric applications

Summary

Most of the pacemakers implanted in paediatrics have been developed for adults. Reduction of the physical dimensions has been the paediatric issue for years. Recent flexible microprocessor-based pacemaker technology permits the development of dedicated algorithms for small patient populations. In order to verify whether the existing adult mode switching (MS) pacemaker algorithm was capable of discriminating between physiological and pathological heart rates in children, an evaluation of the speed of change of sinus rhythm in children during exercise was performed. The maximum heart rate achieved was recorded as well.

Widening the „physiologic band” from 15 to 30min^–1 is required to avoid false positive MS on fast sinus rhythm variations. Increasing the highest programmable maximum tracking rate (MTR) is also desired. However MS on supraventricular tachyarrhythmia‘s (SVT) should remain active. Slow MS or the inability to detect premature atrial contractions (PAC) or SVT below the MTR may introduce large V-V interval variations, e.g. when tracking these events. This may lead to palpitations or R- on T-pacing at rest, when longer cardiac refractory periods are present in combination with high programmed MTR.  Dedicated paediatric algorithms in the Clarity DDDR and Saphir III VDDR pacemakers (Vitatron, Dieren, the Netherlands (include): • Auto MS sensitivity MODERATE • MTR up to 190min^–1• Pacemaker Wenckebach behaviour for high sinus rhythms up to 235min^–1. Selected Event Recording and Mode Switching Trend support the clinician with diagnostic information. This information is automatically collected by the pacemaker during atrial and ventricular tachyarrhythmias and may also contain information that supports decisions to program more optimal pacemaker settings during pacemaker follow up.