This 45-year-old man was diagnosed two years ago with dilated cardiomyopathy of unknown etiology. He was symptom-free until three weeks ago when he started complaining of frequent palpitations associated with weakness and occasional near-syncope. He has been admitted to hospital for further workup and treatment:

• Sinus rhythm with runs of non-sustained monomorphic ventricular tachycardia (VT). Ventricular rate 95/min, VT rate 105/min.
• First degree AV block
• Right bundle branch block
• Left anterior fascicular block

The patient was started on amiodarone, and within two days his palpitations had resolved. He was discharged on Amiodarone 400 mg po daily. The following ECG is recorded two weeks later. He reports that he has remained symptom-free:

• Sinus rhythm – 66/min, with first degree AV block
• Right bundle branch block
• Left anterior fascicular block