Cardiovascular autonomic responses to passive head uptilt in males and females

Autonomic nervous system Posture Blood pressure Head up tilt Original Article AIMS: Orthostatic stress is commonly utilized to evaluate the cardiovascular autonomic function. This is done by Head Up Tilt (HUT).. Tilt table test is a standardized, physiological, clinically relevant stimulus that challenges the cardiovascular regulation. By the performance of head up tilt, it is possible to assess the dynamic capacity of regulatory system. Human responses to head up tilt are a window on Central Nervous System (CNS). MATERIALS AND METHOD: 100 healthy males and females between age group of 15-45 years were selected. A pretested structured proforma was used. Manually operated tilt table was used which is locked at30°,60° and 80°. ECG recordings were observed over monitor for 5 minutes in each position .Blood Pressure (BP) and Heart Rate (HR) were recorded within 20 seconds of change of posture. A repeated measure ANNOVA was used for analysis at different tilts. RESULTS: HR and Diastolic Blood Pressure (DBP), Mean arterial Pressure (MAP) increased on HUT in both males and females. The increase in heart rate in females was less than males. CONCLUSION: During HUT there is increase in sympathetic activity resulting in increase in HR and DPB. The gender differences need to be further investigated. Postural stress test is useful for medical students, physiologist and clinicians to understand cardiovascular reflex response in healthy individuals