Valsalva ratio: a measure of stress in first year medical students

Abstract

INTRODUCTION Valsalva Ratio is a measure of the Heart Rate response to Blood pressure changes resulting from the mechanical and cardiovascular effects of the Valsalva manoeuvre. 1 This method explores cardiac autonomic control based on tachycardia and bradycardia response to sudden short-lasting subsequent and alternating induction and liberation of forced expiration against standardized resistance, resulting in an abrupt reduction and elevation of arterial pressure respectively. 2 It evaluates the integrity of cardiac autonomic function based on heart rate responses associated with the arterial pressure stabilizing baroreflex mechanism. During academic stress the sympathetic activity is increased. The estimated prevalence of emotional disturbance was found in different studies higher than in general population. 3 Medical education poses many new challenging and potentially threatening situational demands as the incoming students throughout the world. An optimal level of stress enhances learning skills while excess of stress can cause health problems and decrease academic performance. The young medical students' population is vulnerable to stress in higher professional education due to competitive environment. Acute and short term stress leads to rapid changes throughout the body. Almost all body system gear up to meet the perceived danger (stress). Continuous changes in sympathetic and parasympathetic neural inputs exhibits alteration in heart rate and causes oscillation of R-R interval around its mean value. One of the most simple and global measure of Heart Rate Variation (HRV) is standard deviation of mean R-R interval in ECG. When ABSTRACT Background: The Valsalva manoeuvre is commonly used as a method of assessing normal or disordered Autonomic control of Blood pressure and Heart Rate. Continuous changes in sympathetic and parasympathetic neural inputs exhibits alteration in Heart Rate and blood pressure which causes oscillation of R-R interval. Acute and short term stress leads to rapid changes throughout the body. Almost all body system gear up to meet the perceived dangers (stress).When healthy subjects are acutely stressed Heart rate increases and R-R interval on ECG decreases transiently. The purpose of the study is to see the changes in VMM in prestress and stress conditions. Methods: 56 non-smoking apparently healthy first year medical students (26 males and 26 females) were selected for the present study. Data collected two month prior to the examination as prestress values and during examination as during stress values. Data analyzed using Wilxcon Rank signed 2 tailed test and the sub groups data analyzed paired t test. Results: 11.54% males and 19.23% females had mild stress in prestress condition. During stress 46.15% males and 19.23% females had mild stress while 34.62% males and 57% of females had severe stress. The female had more stress as compared to males both in prestress and during stress conditions. Conclusion: We conclude that VR is affected by the academic stress in the first year medical students and that among them females are more affected which may be due to the new environment and new protocol of the education system.