Gender Differences and Posture change of Heart Rate Variability between Taiwanese Symptomatic Mitral Valve Prolapse Syndrome and Normal

Heart rate variability (HRV) is the temporal variation between sequences of consecutive heartbeats. On a standard electrocardiogram (ECG), the duration between two adjacent R wave peaks is termed the R-R interval. The resulting period between adjacent QRS complexes resulting from sinus node depolarization is termed the N-N (normal-normal) interval, and HRV is the measurement of the variability of the N-N intervals. The last two decades have witnessed the recognition of a significant relationship between the autonomic nervous system and cardiovascular mortality, including sudden cardiac death. HRV investigation has its use in the prediction of long-term survival in patients who had suffered from congestive myocardial infarction, or had valvular or congenital heart disease. Depressed HRV is a predictor of mortality and arrhythmic complications independent of other recognized risk factors. HRV