Late ventricular arrhythmias in patients with mechanical heart valves and their relation to associated factors

Sudden death is a well known complication of prosthetic heart valve disease. Complex ventricular arrhythmias have been suggested as the cause of this event in part. In this study, we aimed to investigate the incidence and severity of complex ventricular arrhythmias in patients with mechanical heart valves and the relations between complex ventricular arrhythmias and patient and prosthetic valves related factors.

Two hundred and one patients with mechanical heart valve were included in this study. All patients were examined with transthoracic echocardiography, 24 h ambulatory electrocardiography and history including age and gender of patients, type, location, number and duration of prosthesis. Left and right heart chamber dimensions, wall thicknesses were measured and ejection fractions were calculated. Ventricular arrhythmias were classified according to Lown's classification. Grade 3 and 4 were accepted as significant and complex ventricular arrhythmias.

Ventricular arrhythmias and complex ventricular arrhythmias were found in 64% and 34% of patients, respectively. Complex ventricular arrhythmias were not associated with gender, location, type, and number of prosthesis. Age (P=0.003), duration of prosthesis (P=0.003), left ventricular hypertrophy (P<0.001), dilatation (P<0.001), ejection fraction (P<0.001), wall-motion abnormalities (P=0.012) and right ventricular hypertrophy (P=0.026), dilatation (P=0.013), ejection fraction (P=0.003) were significantly related to complex ventricular arrhythmias.

This study suggests that early valve replacement before cardiac anatomy critically impairs may decrease the incidence of complex ventricular arrhythmias. However, the longer duration of prosthesis may cause the more complex ventricular arrhythmias. This may reveal some controversy about the timing of surgery.