New generations of implantable pacemaker defibrillators for ventricular and atrial tachyarrhythmias.

Implantable defibrillation devices have now been extensively applied to patients requiring cardioversion and defibrillation of sustained ventricular tachyarrhythmias. The focus of new developments is in improving technology, achieving physiologic operation in the atrium and ventricle, seeking new indications and identifying patient populations amenable to this therapy. Ventricular application technology is focusing on simplifying and improving robustness of lead systems yet seeking lower defibrillation thresholds. Dual chamber pacing, sensing and defibrillation are being developed. New populations for ventricular application include non-sustained ventricular tachycardia patients with coronary artery disease, dilated cardiomyopathy at risk for sudden death, long QT syndrome, pediatric patients with risk of sudden death and high risk postoperative coronary bypass patients. New applications include atrial defibrillation combined with atrial pacing in future devices. These devices are planned to have capabilities of ventricular defibrillation as a backup to address proarrhythmia concerns. It can be anticipated that implantable cardioverter defibrillator devices will be used for arrhythmia reversion in an expanding group of patients in the future.