Unusual cause for loss of left ventricular capture in patient with cardiac resynchronization due to tuberculous pericarditis

We report a case of 37-year-old man implanted with cardiac resynchronization therapy-defibrillator presented with persistent low-grade fever and sudden loss of left ventricular (LV) capture from coronary sinus lead after generator replacement. ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography scan showed increased uptake at posterolateral region of the pericardium adjacent to the LV lead, suggestive of possible lead-related infection. Combined percutaneous and surgical lead extraction revealed purulent pericarditis and polymerase chain reaction testing confirmed tuberculous (TB) pericarditis. TB pericarditis is an unusual cause of loss of LV capture, but should be considered in countries where TB is still endemic.