Which is a Class I indication for secondary prevention ICD?

Which is a Class I indication for secondary prevention ICD?

• A. Symptomatic VT
• B. Syncope plus induced VT/VF during EP study
• C. AF with rapid ventricular response
• D. Prior history of HF with preserved EF

Answer: (B)

Secondary prevention ICDs are placed after a life‑threatening ventricular arrhythmia or a resuscitated sudden cardiac death to prevent recurrence. When a patient has syncope and an electrophysiology study inducibly reveals VT or VF, this shows a real risk of spontaneous dangerous VT/VF and identifies a substrate capable of malignant rhythms. That combination is a clear Class I indication for ICD implantation for secondary prevention. AF with rapid ventricular response doesn’t reflect a direct risk of VT/VF requiring an ICD, and prior heart failure with preserved ejection fraction isn’t an ICD indication for secondary prevention. Symptomatic VT can be a reason for ICD in other contexts, but the scenario of syncope with inducible VT/VF provides the strongest, guideline-supported justification here.

Secondary prevention ICDs are placed after a life‑threatening ventricular arrhythmia or a resuscitated sudden cardiac death to prevent recurrence. When a patient has syncope and an electrophysiology study inducibly reveals VT or VF, this shows a real risk of spontaneous dangerous VT/VF and identifies a substrate capable of malignant rhythms. That combination is a clear Class I indication for ICD implantation for secondary prevention.

AF with rapid ventricular response doesn’t reflect a direct risk of VT/VF requiring an ICD, and prior heart failure with preserved ejection fraction isn’t an ICD indication for secondary prevention. Symptomatic VT can be a reason for ICD in other contexts, but the scenario of syncope with inducible VT/VF provides the strongest, guideline-supported justification here.