Determination of cardiac output in medical students by pulse pressure method

ABSTRACT

Since stroke volume is the work that heart performs in each heart beat and cardiac output [COP] is expressed as product of stroke volume and heart rate. Pulse pressure is determined approximately by the ratio of stroke volume output to the compliance of arterial tree. We hypothesized that by simply determining pulse pressure COP can be measured and these observations were made before and after moderate exercise in male and female medical students. Male students [n=15] and female students [n=21] belonging to age group 18-25 years weighing 40-65 kg, having no cardiovascular ailment were included in the study. Blood pressure, pulse pressure and heart rate were determined. Hemoglobin estimations were done. There was a significant increase in pulse pressure and hence cardiac output in males and females after exercise. It was more significant in females. COP before exercise in females was 2.90 +/- 0.17 L/min [p<0.001] after exercise 3.42 +/- 0.70 L/min. In male students the COP results were 3.30 +/- 0.20 L/min and 3.90 +/- 0.20 L/min before and after exercise respectively with p<0.05. Our results correspond with standard cardiac output evaluation for these age groups. We conclude that pulse pressure is a good predictor for cardiac output evaluation