LAUSR

A 92‐year‐old gentleman presented with sensation of thumping in the chest. Carelink transmission revealed that he received 15 shocks from his Medtronic Protecta XT DR implantable cardiac defibrillator (ICD) in a 24‐hour period. He had ischemic cardiomyopathy and received a dual chamber ICD 12 years ago after an episode of monomorphic ventricular tachycardia (VT). Amiodarone was discontinued due to interstitial lung disease and since then he had been on metoprolol 50 mg BID. Baseline ECG showed normal sinus rhythm. Subject had previous VT episodes which were terminated with anti‐tachycardia pacing (ATP). He had not had a shock from his device over the past 12 months. Figure 1 showed the interval plot from the recorded event on the ICD. Electrograms of all 15 shocks were similar. What was the cause of his symptoms and how would you manage the patient?