Adverse effects of Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways on cardiac function.

Aims: Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways causes eccentric septal mechanical activation and may provoke left ventricular (LV) dyssynchrony and dysfunction. The aim of the study was to evaluate the effect of radiofrequency catheter ablation (RFA) of the accessory pathways on LV function.

Methods And Results: Retrospectively, transthoracic echocardiography and electrocardiogram recordings were analysed in 34 patients (age: 14.2 +/- 2.5 years) with right septal or posteroseptal accessory pathways prior and after (median: 1 day) successful RFA. Results prior to RFA, LV ejection fraction was decreased (<55%) in 19/34 patients (56%). After RFA, QRS duration was normalized (129 +/- 23 vs. 90 +/- 11, P < 0.0001), LV function improved (ejection fraction: 50 +/- 10 vs. 56 +/- 4%, P = 0.0005) and septal-to-posterior wall motion delay as a global measure for LV dyssynchrony decreased (110 +/- 94 vs. 66 +/- 53, P = 0.012). Longitudinal two-dimensional strain evaluated in five patients demonstrated a decrease of left intraventricular mechanical delay from 292 +/- 125 to 118 +/- 37 ms after RFA.

Conclusion: Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways may cause LV dyssynchrony and jeopardize global LV function. Radiofrequency catheter ablation resulted in normalized QRS duration, mechanical resynchronization, and improved LV function. Even in the absence of arrhythmias, RFA of right septal or posteroseptal pathways may be considered in patients with significantly decreased LV function.