In heart failure patients, an implanted ICD is most beneficial for those with which risk feature?

• A. Recurrent sustained ventricular arrhythmias
• B. Hypertension
• C. Atrial fibrillation without VT
• D. Diabetes mellitus

Answer: (A)

An implanted ICD is designed to detect and terminate life-threatening ventricular tachyarrhythmias (VT/VF) in heart failure patients, thereby reducing the risk of sudden cardiac death. The risk feature that makes ICD therapy most beneficial is a history of recurrent sustained ventricular arrhythmias. This directly shows a propensity for dangerous rhythms that can abruptly lead to death, and ICDs have proven mortality benefit by terminating those episodes. Hypertension and diabetes mellitus contribute to overall cardiovascular risk but do not by themselves indicate a current tendency toward malignant ventricular arrhythmias requiring device therapy. Atrial fibrillation without VT likewise does not reflect a ventricular arrhythmia that the ICD is designed to treat.