Orthostatic Stress Induced Changes in Heart Rate Variability, Pulse Transit Time and QRS Duration

Cardiovascular disease (CVD) is the leading cause of death in United States. Various parameters can provide useful insight into the health of cardiovascular system. Heart rate variability (HRV) can be used to determine the level of stress during daily activity. QRS complex width has beenshown to predict risk of sudden cardiac death and increased mortality inpatients with congestive heart failure.Pulse transit time (PTT) can provide information about arterial stiffness, and pulse transit time variability (PTTV) can be used as a marker of blood pressure variability (BPV). Both arterial tone and BPV are risk factors for CVD.

Previous studies had looked at these parameters independently and there is no information about their interaction. Our objective is to studythe changes in HRV, QRS duration and PTT by orthostatic stress. We are going to study the effect of orthostatic stress and interaction of these parameters using data collected from a subject population. We will also investigative population characteristics based changed in these parameters.