INTER-VENTRICULAR SEPTAL THICKNESS AND LEFT-VENTRICULAR HYPERTROPHY - ECHOCARDIOGRAPHIC STUDY

Septal and left ventricular posterior wall (LVPW) thicknesses and their ratios were studied at the left ventricular outflow tract and left ventricular cavity in 66 patients with echocardiographically diagnosed left ventricular concentric hypertrophy, 20 with idiopathic hypertrophic subaortic stenosis (IHSS), and 34 normal subjects. Concentric hypertrophy was due to hypertension in 41 subjects and to valvular disease in 15 subjects. Septal thickness in normal subjects was related to body surface area (p<0.02). In 12% of normal subjects, 39% of patients with concentric hypertrophy and 95% with IHSS, the septal/LVPW ratio was ≥1.3. Thirty-two percent of patients with hypertension, 78% with aortic stenosis, and 60% with aortic insufficiency had septal/LVPW ratios ≥1.3 at left ventricular midcavity level. In conclusion, a septal/LVPW thickness ratio of ≥1.3 common in patients with concentric left ventricular hypertrophy and may also occur in normal subjects. A ratio ≥1.5 may be more specific for genetically determined asymmetric septal hypertrophy.