[Reliability and limitation of various diagnostic methods including nuclear medicine in myocardial disease (author's transl)].

Electrocardiography (ECG), echocardiography, nuclear method, cardiac catheterization, left ventriculography (LVG) and endomyocardial biopsy (biopsy) were performed in 40 cases of cardiomyopathy (CM), 9 of endocardial fibroelastosis (EFE) and 19 of specific heart muscle disease (SHMD), and the usefulness and limitation of each method was comparatively estimated. In CM, various methods including biopsy were performed. The 40 patients were classified into 3 groups, i.e., 1) hypertrophic (17), 2) dilated (20) and 3) non-hypertrophic . non-dilated (3) on the basis of left ventricular ejection fraction (LVEF) and hypertrophy of the ventricular wall assessed by LVG and/or echocardiography. The hypertrophic group was divided into 4 subgroups: 9 septal, 4 apical, 2 posterior and 2 anterior. M-mode scan was useful for detecting hypertrophy at the site of the ventricular septum and posterior wall, but not at the site of the anterior wall and apex. The hypertrophy was detected in 18 out of 20 cases using nuclear method. The posterior wall was hypertrophic but the septum was normal in 2 cases. In 2 of 3 non-hypertrophic . non-dilated cases, the left ventricle was oval in shape by LVG, echocardiography was normal, but significant pathological changes were seen in the biopsy, and there were abnormal ECG findings. There was no correlation between the ECG findings and the site of ventricular hypertrophy. Left ventricular ejection fraction measured by LVG (Kasser) had a closer correlation to LVEF obtained by nuclear method (multigated blood pool scan; r = 0.97) than LVEF by echocardiography (Teichholz; r = 0.79), although LVEF obtained by nuclear method was slightly higher than LVEF obtained by LVG. Myocardial perfusion defect was found in 10 of 20 cases of dilated cardiomyopathy (DCM) and the site of relative hypokinesis coincided with the site of the defect in 6 of 7 cases. A semi-quantitative myocardial perfusion defect index (PDI) and histo pathological contractility failure index (HCFI) obtained by the biopsy were devised. HCFI is the score of myocardial degeneration, fragmentation and fibrosis. The PDI plus HCFI had a close correlation with LVEF (r = -0.898). In 9 cases of DCM, LVEF was more reduced than right ventricular ejection fraction. The perfusion defect was also found in 4 cases of EFE and 4 cases of SHMD, i.e., sarcoidosis, postmyocarditis, Kugelberg-Welander disease and cardiac tumor. We conclude that the nuclear study is useful in assessing the site of the abnormal ventricular thickening, perfusion defect and ventricular function. Echocardiography is most useful in detecting ASH. The biopsy gives the sole diagnostic clue, especially in non-hypertrophic . non-dilated cardiomyopathy. ECG is useful in all cases but correlation with the site of disproportional hypertrophy was not obtained.