Dilated cardiomyopathy relieved as a result of beta-blocker therapy: a case report--key points in assessment of prognosis based on MIBG myocardial scintigraphy and BNP levels.

A 48-year-old male patient was admitted to our hospital with dyspnea accompanied by orthopnea. Chest x-rays showed a cardiothoracic ratio of 68% and pulmonary congestion. He was diagnosed with dilated cardiomyopathy. Beta-Blocker (carvedilol) therapy was initiated on Day 22 of the disease using a small initial dose. He was followed up based on BNP levels and MIBG scintigraphy. The H/M ratio and MIBG washout rate were 1.98 and 33.4%, respectively, on Day 20 and 2.15 and 28.1%, respectively, on Day 72. The patient was discharged on Day 72 when congestive heart failure improved. Relatively high BNP levels were observed for 1 month after starting treatment with a beta-blocker. Plasma BNP levels were still as high when his heart failure was improved. BNP is useful as a convenient indicator for the severity of cardiac diseases. MIBG scintigraphy may be used thereafter to evaluate the severity in greater detail and more precisely determine the prognosis.