Risk factors for systolic dysfunction and ventricular dilatation in hypertrophic cardiomyopathy.

The history of an 18-year-old male with hypertrophic cardiomyopathy (HCM) and ventricular dilatation is presented and the literature on systolic dysfunction and ventricular dilatation in patients with HCM is statistically analyzed in search of risk factors. The patient was followed for 7 years when he developed recurrent ventricular fibrillation, left ventricular dilatation and low cardiac output. An automatic cardioverter-defibrillator was implanted but the patient died of electro-mechanical dissociation. In order to define risk factors for systolic dysfunction and ventricular dilatation in HCM, the literature data of 17 patients with this complication were compared to a group of 139 consecutive patients with HCM from our hospital. The risk factors identified were a more markedly increased septal (20.1 vs. 18.0 mm, P < 0.05) and posterior wall thickness (13.6 vs. 11.0 mm, P < 0.001) in the patients subsequently developing systolic dysfunction and ventricular dilatation, whereas age, sex and the ratio between septal and posterior wall thickness were not significantly different between the two groups. A severely increased ventricular mass appears to be a risk factor for the development of systolic dysfunction with ventricular dilatation in HCM. Prognosis is usually poor and the reported case showed fatal ventricular arrhythmia despite the implantation of an automatic cardioverter-defibrillator.