Abnormal septal Q waves in sickle cell disease. Prevalence and causative factors.

Electrocardiograms and M-mode echocardiograms were obtained prospectively from 72 patients with hemoglobin SS (n = 55) or SC (n = 17) disease to assess the prevalence of abnormal Q waves in sickle cell disease and to determine if such Q waves could be explained by, or related to, echocardiographically determined anatomic or functional abnormalities. The mean age (+/- SD) of the population under study was 28 +/- 9 years, and the mean hematocrit reading was 28 +/- 5 percent; 43 male and 29 female patients were evaluated. No patient had a history of systemic arterial hypertension, valvular heart disease, or congestive heart failure. Abnormal septal Q waves (amplitude greater than or equal to 0.30 mV; duration less than or equal to 29 msec) were noted in leads V4, V5, or V6 in 15 of 72 patients, and 50 percent (36) of the population under study demonstrated electrocardiographic voltage changes consistent with left ventricular hypertrophy. M-mode echocardiography showed that 29 of 72 patients had a thickened interventricular septum (greater than or equal to 1.2 cm), 16 of 72 had an abnormally thickened left ventricular posterior wall (greater than or equal to 1.2 cm), and 31 of 72 had increased left ventricular mass (greater than 215 g). The prevalence of electrocardiographic and echocardiographic abnormalities was not significantly different between patients with hemoglobin SS and SC disease. Septal excursion was decreased in 11 of the patients, and global left ventricular function (percent fractional shortening) was slightly decreased in three patients. Regional wall motion was normal in all 72 patients. Six percent (four) of the patients met echocardiographic criteria for asymmetric septal hypertrophy. Linear regression analysis yielded significant positive correlations between septal dimension (r = 0.38; p less than 0.001) and left ventricular mass (r = 0.37; p less than 0.005) when each was compared with Q-wave amplitude. A significant negative correlation (r = 0.40; p less than 0.001) was noted between hematocrit reading and Q-wave amplitude. We conclude that abnormal septal Q waves are common in sickle cell disease and are related, in part, to septal thickness, as well as left ventricular mass and degree of anemia.