Which Patients with ICD May Really Benefit from DDD Pacing, and Which Won’t?

Abstract

The efficacy of implantable cardioverter-defibrillators (ICD) in preventing sudden death has been shown by several trials. Nonetheless two functions need to be improved: (1) the identification of arrhythmias other than VF (supraventricular or ventricular fibrillation) in order to reduce inappropiate shocks, (2) the quality of cardiac pacing. Dual-chamber pacing should be the stimulation method of choice in patients with depressed sinus node function, or in those who are pacemaker dependent, when effective atrial pacing and sensing can be achieved. In contrast, patients with an implatable cardioverter defibrillator (ICD) who also need antibradycardia pacing, can currently receive only fixed rate ventricular pacing, even though most of them have depressed sinus node function. Furthermore, positive hemodynamic effects of atrioventricular sequential pacing in patients with left ventricular dysfunction have been described so far [1, 2]. In fact the preservation of atrioventricular synchronization can result in a positive effect on the morbility and perhaps on the mortality of pacemaker dependent patients [1].