Ventricular preexcitation associated with dilated cardiomyopathy: a causal relationship?

Over a six year period, we identified four children with dilated cardiomyopathy associated with ventricular preexcitation, three in the absence of any documented tachyarrhythmias, and one with but a solitary episode of tachyarrhythmia. None of them had another identifiable aetiology for the cardiomyopathy. Based on the 12 lead electrocardiogram, and/or invasive electrophysiologic studies, we localised the accessory pathways to the right atrioventricular groove in all patients. We commenced antifailure medications in two of the four patients, but did not produce any measurable improvement in ventricular function. Catheter ablation was performed in two patients, with resolution of the cardiomyopathy. The ventricular preexcitation disappeared spontaneously in one child during follow-up, again with resolution of cardiomyopathy. The youngest patient continues to receive antifailure medications, albeit without improvement. We suggest, therefore, that dilated cardiomyopathy of reversible nature is associated with manifest ventricular preexcitation, even in the absence of sustained arrhythmias.