Prolongation of QT interval and ventricular septal hypertrophy.
Long QT syndrome (LQTS) is a prime example of interplay between molecular biology, cellular physiology, and organ physiology. Both the congenital and acquired forms of LQTS are due to intrinsic and/or acquired abnormalities of the ionic currents responsible for cardiac repolarization. We analyzed the QTc interval, QRS axes and interventricular septal thickness (IVST) in 41 patients who had a prolonged QT interval on routine electrocardiography (ECG) (5 females and 36 males, mean age 65+/-13 years). The QRS axis of patients in the LQTS group (27+/-49 degrees) was significantly lower (p < 0.05) than in the control group (46+/-26 degrees). However, the IVST in the LQTS group (10+/-2 mm) was significantly thicker than in the control group (9+/-1 mm) (p < 0.05), while the WTd was not significantly different. The QTc interval in patients with ventricular septal hypertrophy (IVST > or = 12 min, 478.8+/-7.9 msec) was significantly longer (p < 0.05) than in the normal group (IVST < 12 mm, 472.1+/-17.5 msec). In conclusion, the results of this preliminary study suggest that prolongation of the QT interval on ECG should prompt screening for electrocardiographic evidence of ventricular hypertrophy in patients with this disease.
Kotajima
N
N
Department of Laboratory Medicine, Gunma University School of Medicine, Maebashi, Japan.
Hirakata
T
T
Kanda
T
T
Yokoyama
T
T
Hoshino
Y
Y
Tanaka
T
T
Tamura
J
J
Nagai
R
R
Kobayasii
I
I
D000328:Adult; D000368:Aged; D004562:Electrocardiography; D005260:Female; D006346:Heart Septum / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000473:pathology*; D008133:Long QT Syndrome / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography