Reversible left ventricular dyssynchrony and dysfunction resulting from right ventricular pre-excitation.

We report observations in a 7-year-old girl with right ventricular pre-excitation due to an accessory atrioventricular pathway (AP), and depressed cardiac function. Echocardiographic findings consisted of left ventricular (LV) dilatation with asynchronous ventricular wall motion and diminished LV ejection fraction. Electrophysiological study revealed a para-Hisian AP. She underwent successful AP ablation, after which asynchronous ventricular wall motion disappeared. Cardiac size and function were normal after 3 months follow-up. These findings suggest that ventricular pre-excitation leading to asynchronous ventricular motion was a possible cause of LV dilation and dysfunction and that catheter ablation reversed undesirable cardiac remodelling in this patient.