Implantable cardioverter-defibrillators: implications for the nonelectrophysiologist

To review clinical scenarios in which nonelectrophysiologist physicians may interact with patients who have implantable defibrillators.

Peer-reviewed original articles and reviews addressing aspects of implantable defibrillator therapy that are relevant to the clinician.

The capacity of implantable defibrillators to recognize and treat tachyarrhythmias can be temporarily disabled by placing a magnet on top of all devices. General surgery, radiotherapy, lithotripsy, and electroconvulsive therapy can usually be safely done under continuous electrocardiographic monitoring in patients with implantable defibrillators. The device should be deactivated before the procedure is done and reactivated and reassessed immediately afterward. Magnetic resonance imaging is usually contraindicated in patients wit implantable defibrillators. The presence of an implantable defibrillator should not deter standard resuscitation techniques. Multiple defibrillator discharges in a short period of time represent a serious problem. Causes of multiple discharges include ventricular electric storm, inefficient defibrillation, nonsustained ventricular tachycardia, and inappropriate shocks caused by supraventricular tachyarrhythmias or oversensing of signals. These patients should be initially evaluated in a setting that allows electrocardiographic monitoring and cardiac resuscitation. The defibrillator should be deactivated if inappropriate firing is documented. Infections of implantable defibrillator systems are potentially life-threatening, and empiric oral antibiotic therapy should never be given when this possibility exists. Adjustment disorders specific to the defibrillator, including anxiety with secondary panic reaction; defibrillator dependence, abuse, or withdrawal; and imaginary shocks are not uncommon.

Defibrillator therapy has become increasingly popular and complex. A basic understanding of these devices and skills in the short-term management of device-related problems is valuable for most physicians. These management guidelines will facilitate delivery of optimal care when specialized staff and material resources are not available.