Dyssynchronous ventricular activation in asymptomatic wolff-Parkinson-white syndrome: a risk factor for development of dilated cardiomyopathy

Abstract

A subset of children and adults with Wolff-Parkinson-White (WPW) syndrome develop dilated cardiomyopathy (DCM). Although DCM may occur in symptomatic WPW patients with sustained tachyarrhythmias, emerging evidence suggests that significant left ventricular dysfunction may arise in WPW in the absence of incessant tachyarrhythmias. An invariable electrophysiological feature in this non-tachyarrhythmia type of DCM is the presence of a right-sided septal or paraseptal accessory pathway. It is thought that premature ventricular activation over these accessory pathways induces septal wall motion abnormalities and ventricular dyssynchrony. LV dyssynchrony induces cellular and structural ventricular remodelling, which may have detrimental effects on cardiac performance. This review summarizes recent evidence for development of DCM in asymptomatic patients with WPW, discusses its pathogenesis, clinical presentation, management and treatment. The prognosis of accessory pathway-induced DCM is excellent. LV dysfunction reverses following catheter ablation of the accessory pathway, suggesting an association between DCM and ventricular preexcitation. Accessory pathway-induced DCM should be suspected in all patients presenting with heart failure and overt ventricular preexcitation, in whom no cause for their DCM can be found.

Keywords: Wolf-Parkinson-White syndrome; accessory pathway; catheter ablation; dilated cardiomyopathy; dyssynchrony; speckle tracking imaging.

Figure 1

Radial strain assessment using 2D speckle tracking echocardiography. Radial two-dimensional strain in the parasternal short-axis view at the mid-ventricular level of a child with a septal accessory pathway and LV dysfunction. There is an inhomogeneous pattern of radial strain, with severely reduced peak radial strain values for septal myocardial segments (yellow and red arrows). Radial peak strain values are presented as positive values.

Figure 2

Longitudinal peak systolic strain values and curves of 6 myocardial segments obtained from a 4-chamber view in the same patient as in Figure 1. The septal basal segment (yellow arrow) shows reduced longitudinal peak systolic strain compared to the other segments. The septal basal segment stretches and relaxes in early systole, demonstrating regional systolic dysfunction. In addition, maximal peak systolic strain occurs after closure of the aortic valve (AVC). This part of the ventricle may function as an aneurysm during follow-up, inducing adverse remodelling and dyssynchrony (see text for further explanation).