IS THERE INCREASED SYMPATHETIC ACTIVITY IN PATIENTS WITH MITRAL-VALVEPROLAPSE

The aim of this study was to investigate autonomic nervous system tone in patients with mitral valve prolapse (MVP). Heart rate variability (HRV) was assessed from 24-hour ambulatory Holter recordings in 28 pat ients with primary MVP and in 28 age and sex matched normal control su bjects in a drug-free state. Sixteen of the MVP patients were symptoma tic and 12 asymptomatic. Spectral HRV was calculated in terms of low ( LF: 0.06-0.15 Hz) and high (HF: 0.15-0.40 Hz) frequency components usi ng fast Fourier transform analysis, and the ratio LF/HF was calculated . Spectral analysis of HRV showed that the MVP patients, taken as a si ngle group, had lower HF and LF and a higher LF/HF ratio than the cont rols. No significant difference in HRV was found between the Is sympto matic and the 12 asymptomatic patients, but the symptomatic patients h ad a significantly higher LF/HF ratio than the controls. Our observati ons suggest that, during normal daily activities, patients with MVP ex perience a significant deviation in autonomic nervous system tone with predominance of the sympathetic branch. This predominance is more mar ked in symptomatic patients.