Morphological quantification and differentiation of left ventricular hypertrophy in hypertrophic cardiomyopathy and hypertensive heart disease. A two dimensional echocardiographic study.

Differentiation between hypertrophic cardiomyopathy and hypertensive heart disease is a diagnostic challenge. M-mode echocardiography only permits assessment of hypertrophy in limited areas of the left ventricular wall. 2-D echocardiography allows visualization of most of the myocardium. To assess the reliability of conventional M-mode echocardiographic and 2-D echocardiographic criteria in patients with hypertrophic cardiomyopathy (HCM) and hypertensive heart disease (HY), 30 patients with hypertrophic cardiomyopathy and 30 patients with hypertension and severe cardiac hypertrophy were examined using M-mode and 2-D echocardiography. Although the M-mode echocardiographic features showed statistically significant differences between the mean values in the two groups, the degree of overlap made the differentiation of the individual patients difficult. The diagnostic sensitivity and specificity of classic echocardiographic features were assessed: ventricular septal thickness greater than or equal to 1.5 cm, 90% and 43% (sensitivity and specificity, respectively); ventricular septal thickness to posterior wall ratio greater than or equal to 1.5, 83% and 56%; cross-sectional area at papillary level greater than 21 cm2m-2, 80% and 73%; septal segment of the myocardial ring at papillary level greater than 6.5 cm2m-2, 80% and 87%; and the combined criteria of cross-sectional area at papillary level greater than 21 cm2m-2 and septal segment greater than 6.5 cm2m-2, 77% and 93%. Quantitative 2-D echocardiography is useful to differentiate patients with hypertrophic cardiomyopathy from those with secondary myocardial hypertrophy due to hypertension. Hypertrophic cardiomyopathy is characterized by a spectrum of different morphological patterns of hypertrophy. Patients with the predominant region of hypertrophy in the anterolateral free wall or the apical region of the left ventricle were not detected with our quantitative method. Patients with this type of hypertrophy are relatively rare in the western population.