ECG of the month. Irregular rhythm in a 25-year-old man with three prior cardiac operations. Coarse atrial fibrillation with a rapid ventricular response, left anterior fascicular block, left ventricular hypertrophy with repolarization abnormality.

: The patient underwent closure of an atrial septal defect at age 3, had a leaking "mitral" valve repaired at age 9, and at age 13 had a "mitral" valve replacement. He began taking warfarin sodium at that time and remained symptom-free until 10 days before his initial visit here when he presented to another hospital with dyspnea and palpitations. Treatment there consisted of lisinopril 10 mg qd, carvedilol 6.25 mg bid, aldactone 25 mg qd, furosemide 40 mg qd, digoxin 0.25 mg qd, and a continuation of warfarin sodium 7.5 mg qd. An echocardiogram showed a left ventricular ejection fraction of 20%. After diuresis, he was referred to our cardiology clinic. On his initial visit here, his heart rate was an irregular 120 beats/min, his blood pressure was 106/77 mmHg, and closing and opening snaps of a normally functioning mechanical mitral valvular prosthesis were heard. He was obese (height, 5' 9"; weight, 272 lbs). An electrocardiogram was recorded (Figure 1).