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 abnoma1ities 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°) was significantly lower (p < 0.05) than in the control group (46 ± 26°). 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 ≥ 12 mm, 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.
2000 by the Japanese Heart Journal