Effect of exercise on heart rate recovery index in normotensive offspring with family history of hypertension

Background: The relationship between autonomic system and cardiovascular mortality is significant and this study can be used to study the hereditary risk that an individual carries to develop any autonomic dysfunction and its effect on cardiovascular status. In this study, we aimed to investigate the heart rate recovery index and prevalence of cardiovascular risks in subjects with hypertensive parents.Methods: A total of 30 subjects and 30 healthy controls were recruited in the study. Their anthropometrical and cardiovascular parameters were recorded. Heart rate, blood pressure, weight and height of subjects were measured and BMI calculated. After 3 min step test heart rate will be measured in 1, 2, 3 and 5 minute and heart rate recovery index calculated by subtracting maximum heart rate achieved during exercise by heart rate measured in 1,2,3 and 5 minute. The heart rate recovery index (HRRI) is calculated by extracting the maximum heart rate during treadmill stress testing from the heart rate.Results: The 1st minute HRRI was not significantly different in the groups (43.87±11.54 and 43.00±18.77 respectively, p=0.88). Likewise, the 2nd minute HRRI (50.07±10.38and49.07±16.32 respectively, p=0.843), 3rd minute HRRI (53.33±12.72 and 53.60±17.56 respectively, p=0.962), 4th minute HRRI (55.07±13.25 and 54.60±14.73 respectively, p= 0.928) and 5th minute HRRI (56.33±14.58 and 54.87±14.93 respectively, p=0.788) were also not significantly different.Conclusions: Findings of this study suggest that in the absence high arterial pressure and other comorbidities, a family history of hypertension is not accompanied by dysfunction of autonomic system.