Causes and Prevention of Inappropriate Implantable Cardioverter-Defibrillator Shocks.

Use of implantable cardioverter-defibrillators as a primary prevention therapy has been shown to reduce mortality in patients after cardiac arrest and also with left ventricular systolic dysfunction. Yet, inappropriate shocks are variably reported and associated with a reduction in quality of life. Inappropriate shocks are the result of environmental causes leading to electromagnetic interference and inappropriate sensing of external noise, device-related causes from inappropriate sensing of physiologic or pathologic signals, and supraventricular arrhythmias. Strategies to reduce inappropriate shocks include aggressive treatment of supraventricular tachycardia, changes in device programming including prolonged detection time, programming antitachycardic pacing and using discriminator algorithms, and cardiac rehabilitation.