Hypertrophic obstructive and non-obstructive cardiomyopathy in Japan. Diagnosis of the disease with special reference to endomyocardial catheter biopsy.

There were 84 confirmed cases of congestive (or dilated) cardiomyopathy (CCM or DCM), 57 of hypertrophic nonobstructive cardiomyopathy (HNCM) and 52 of hypertrophic obstructive cardiomyopathy (HOCM) collected from 15 cardiology divisions of university or national hospitals in Japan. Out of the 193 patients with cardiomyopathy, 145 (75%) were male and 48 (25%) female (M/F ratio = 3:1). The mean age of the patients was 34.1 years. Patients with HNCM or HOCM were usually asymptomatic, but palpitation was the most common symptom, followed in frequency by chest oppression, dyspnoea, chest pain, arrhythmia and syncope in HNCM, and by dyspnoea, chest oppression, chest pain, dizziness and syncope in HOCM. ST-T abnormalities were most frequently observed, 90.3% in HNCM and 86.3% in HOCM. Left ventricular hypertrophy was observed in 76.4% of HNCM and in 79.1% of HOCM. Abnormal Q waves were observed equally in HNCM (32.4%) and in HOCM (35.3%). A fourth sound was more common (69.2% in HNCM; 75.8% in HOCM) than a third sound (39.7% in HNCM; 36.5 in HOCM). The heart size on conventional radiography was within normal limits or slightly enlarged; the mean cardiothoracic ratio was 0.52 in HNCM and 0.54 in HOCM. A cumulative survival rate in 149 patients with hypertrophic cardiomyopathy demonstrated that the 10-year survival rate after the time when the diagnosis was made was 34.2% for CCM, 81.7% for HNCM and 84.4% for HOCM. Autopsy studies in 11 patients with hypertrophic cardiomyopathy revealed that marked fibre disarray of the heart could be detected by the endomyocardial biopsy of the right ventricular septum in 40% at most of the patients with hypertrophic cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)