title: The electrocardiogram in asymmetric septal hypertropy.
abstract: Electrocardiograms and echocardiograms in 44 patients with asymmetric septal hypertrophy were reviewed. Patients with asymmetric septal hypertrophy had incidences of left ventricular hypertrophy (33 percent; 16/44) and left atrial hypertrophy (25 percent; 11/44) by ECG that were less than in a group of patients with significant aortic stenosis (70 percent [31/44] and 64 percent [28/44], respectively). Left ventricular hypertrophy on the ECG was associated with a greater septal-posterior wall thickness ratio in asymmetric septal hypertrophy. A small Q wave in lead V4 or a ratio of the R-wave to the S-wave amplitude (R/S ratio) of greater than 0.20 in lead V1 was found in 14 of 44 patients with asymmetric septal hypertrophy but in no patients with aortic stenosis. The mean corrected Q-T interval (Q-Tc) of patients with asymmetric septal hypertrophy was prolonged, and the mean Q-Tc of patients with aortic stenosis was normal. The distinctive findings of an R/S ratio of more than 0.2 in lead V1 and Q waves in lead V4 in asymmetric septal hypertrophy have clinical significance, and the prolonged Q-T interval may relate to sudden death.
mesh_terms: D000328:Adult; D000368:Aged; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology; D006332:Cardiomegaly / Q000175:diagnosis* / Q000503:physiopathology; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria; D006329:Heart Conduction System / Q000503:physiopathology*; D006346:Heart Septum; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology