Exercise worsening of electromechanical disturbances: A predictor of arrhythmia in long QT syndrome.

Background: Electromechanical (EM) coupling heterogeneity is significant in long QT syndrome (LQTS), particularly in symptomatic patients; EM window (EMW) has been proposed as an indicator of interaction and a better predictor of arrhythmia than QTc.

Hypothesis: To investigate the dynamic response of EMW to exercise in LQTS and its predictive value of arrhythmia.

Methods: Forty-seven LQTS carriers (45 ± 15 years, 20 with arrhythmic events), and 35 controls underwent exercise echocardiogram.