QRST isointegral departure mapping after exercise in patients with congenital long QT syndrome

Abstract

Congenital long QT syndrome (LQTS) is known to be a critical syndrome associated with a bizarre T wave, prolonged QT interval, and ventricular arrhythmias and is followed by syncope and/or sudden death. Body surface mapping, especially QRST isointegral departure mapping, was used after exercise to assess exercise-induced repolarization changes in patients with this syndrome. This study included 12 patients with the Romano-Ward syndrome (LQTS group, 9 women, 30 ± 19 years) and 19 healthy adults (control group, 5 women, 24 ± 5 years). In the LQTS group, there was a significant increase in the number of local extrema and abnormal points after exercise in the departure maps. In the LQTS group, QRST isointegral departure mapping presented more marked abnormalities of repolarization after an exercise stress test. In mild cases that revealed abnormalities only after the exercise stress, such testing may be helpful for LQTS diagnosis.