Unusual tachycardia-bradycardia syndrome during atrial fibrillation: What is the mechanism?

摘要

A 60-year-old man with a history of remote myocarditis and residual mild left ventricular dysfunction presented with syncope. Before admission, the patient was not taking any regular medications. Medical history was otherwise unremarkable. Examination at presentation was unremarkable, apart from slow atrial fibrillation (AF). ECG on presentation demonstrated AF with slow ventricular response and a complete left bundle-branch block (Figure 1). Inpatient telemetry demonstrated episodes of nonsustained ventricular tachycardia (VT). Cardiac catheterization with coronary angiography was normal. Echocardiogram demonstrated mild left ventricular dysfunction (ejection fraction 50%) but was otherwise unremarkable.