A Case of Dilated Cardiomyopathy Reversed with Conversion of Atrial Fibrillation and β-blocker Therapy
We report here a case of dilated cardiomyopathy reversed with both conversion to sinus rhythm and a consequent long-term β-blocker therapy. The patient was a 47-year-old man with a 3-month history of dyspnea. On admission, electrocardiogram showed atrial fibrillation with a rapid ventricular response. Left ventricular dilatation with markedly diffuse hypokinesis and an estimated ejection fraction of 22% were noted on echocardiogram. Coronary angiography revealed no significant coronary disease. A diagnosis of dilated cardiomyopathy with atrial fibrillation was made, and he was treated with digoxin, diuretics, angiotensin-converting enzyme inhibitors and warfarin. Electrical cardioversion was successfully done, followed by β-blocker therapy. Metoprolol as a β-blocker therapy was given at an initial dose of 5 mg daily and was progressively increased to 40 mg over a four-week period. During the next 6 months, a gradual clinical improvement was found. His echocardiogram performed 20-months later showed that the ejection fraction was 64% with normal left ventricular function. Thus, gradual but complete resolusion of his cardiac dysfunction was noted. The clinical significance of conversion to sinus rhythm in patients with left ventricular dysfunction complicated by atrial fibrillation was discussed.