Histopathological analysis of abnormal electrocardiographic findings in hypertrophic cardiomyopathy--with biopsied ventricular myocardium.

Abstract

To clarify the relationship between electrocardiographic abnor malities and the histopathology of hypertrophic cardiomyopathy (HCM), 43 cases of HCM were studied electrocardiographically observing 1) abnormal Q waves, 2) QRS axis and voltages, 3) depth of negative P waves in V1, 4) giant negative T waves and 5) degree of ST segment depression. Each biopsied specimen was checked microscopically for 1) hypertrophy, 2) disarray and 3) fibrosis. Hypertrophy was graded from (0) to (3+) by the mean value of the shortest transverse diameters of at least 30 myocytes under hematoxylin-eosin stain. Disarray was graded from (0) to (3+) according to the degree of disarrangement of the myocytes under phosphotungstic acid-hematoxylin stain. Fibrosis was graded from (0) to (3+) by the % area counting method under Malloryazan stain. Multiple abnormal Q waves were associated with fibrosis in the presence of hypertrophy (p<0.01). HCM with SV1+RV5-6<35 mm had significantly more advanced fibrosis (p<0.001) and disarray (p<0.01) than HCM with SV1+RV5-6≥35 mm. The depth of the negative P in V1 reflected the degree of hypertrophy, disarray and fibrosis in HCM. HCM with giant negative T waves and ST segment depression (≥ 2 mm) had significantly milder fibrosis (p<0.01) and milder disarray (p<0.05) in the presence of hypertrophy.