The distribution of left ventricular hypertrophy in hypertrophic cardiomyopathy: comparison to athletes and hypertensives.

Cross-sectional echocardiography was performed in 134 patients with hypertrophic cardiomyopathy and 75 with secondary left ventricular hypertrophy (57 hypertensives and 18 athletes) to determine the diagnostic sensitivity and specificity and predictive value of the pattern of left ventricular hypertrophy. Myocardial wall thickness was assessed in the anterior and posterior septum, free wall and posterior wall in both the upper and lower left ventricle. All patients had at least one region exceeding 2 SD from normal (greater than 1.4 cm). Asymmetrical septal hypertrophy) septum to posterior wall ratio greater than or equal to 1.5:1 in the upper or lower left ventricle) was found in 75 patients with hypertrophic cardiomyopathy (56%), 11 hypertensives (18%) and 4 (22%) athletes. This pattern was more common in patients with primary compared to secondary left ventricular hypertrophy (P less than 0.01). Distal ventricular hypertrophy was only seen in patients with hypertrophic cardiomyopathy (10%). Symmetrical left ventricular hypertrophy was demonstrated in 45 patients with hypertrophic cardiomyopathy (34%), 50 hypertensives (82%) and 14 athletes (78%). This pattern was significantly more common in patients with secondary left ventricular hypertrophy (P less than 0.01). Amongst those with symmetrical hypertrophy, patients with hypertrophic cardiomyopathy had more severe hypertrophy while the athletes had larger left ventricular cavity size. Asymmetrical septal hypertrophy was the most sensitive (56%) and distal ventricular (100%) the most specific pattern for the diagnosis of hypertrophic cardiomyopathy with a predictive value of 83 and 100% respectively. Symmetrical left ventricular hypertrophy was 81% sensitive and 66% specific with a predictive value of 58% for the diagnosis of secondary hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)