Arrhythmias in Patients with Mitral Valve Prolapse

Resting ECGs, 24 hour ambulatory ECGs and treadmill exercise tests were performed in 51 symptomatic patients with mitral valve prolapse (MVP) and in 54 similarly symptomatic control subjects. During 24 hour ambulatory monitoring, the incidences of ventricular premature contractions (VPCs), atrial premature contractions (APCs) and bradyarrhythmias (including severe sinus bradycardia, sinoatrial block and Mobitz type I atrioventricular block) were observed in 71%, 69% and 10% of the patients with MVP and in 59%, 65% and 4% of the control group. The differences were not statistically significant. However, the patients with MVP had significantly greater incidences of multiform VPCs and complex VPCs than the control group. (Which were 25% vs 6%, p＜0.01; 33% vs 11%, p＜0.02, respectively). In patients with MVP, prevalence of VPCs, APCs and bradyarrhythmias on treadmill exercise tests were 29%, 4% and 0% respectively, and on resting 12 lead ECGs were 14%, 0% and 0% respectively; therefore, 24 hour ambulatory monitoring was the most sensitive method for arrhythmia detection. However, exercise induced the appearance of complex VPSc in 2 patients. The incidences of VPCs, complex VPCs and APCs during sleep in patients with MVP were 47%, 4% and 37% respectively, these were significantly less than those during the awake period, which were 65%, 31% and 55% respectively. (p＜0.05, p＜0.01 and p＜0.05 respectively). In conclusion, there were no significant differences in the incidences of VPCs, APCs and bradyarrhythmias in patients with MVP and similarly symptomatic control group. However, there was significantly more complex VPCs in patients with MVP. The findings of this study suggest that 24 hour ambulatory ECG and treadmill exercise ECG should be performed in patients with MVP for detecton of this probable risk ventricular arrhythmia.