Most likely, yes. ICDs have been proven to terminate 98% of potentially life-threatening arrhythmias. ICDs save lives every day, but there are certain medical conditions that, if persistent, can prevent the device from saving the person it's implanted in. ICDs can slow down life threatening fast heart beats with an electrical impulse, called defibrillation, or by pacing the heart to slow the rhythm down, called anti tachycardia pacing (ATP). Most people don't even know when they are receiving ATP therapy.