Comparison of Myocardial Oxygen Demand and Rate of Perceived Exertion According to the Modes of Exercise in Ischemic Heart Disease

Kim, Chul; Kim, Young Joo

Abstract

OBJECTIVE
To investigate the changes of myocardial oxygen demand and rate of perceived exertion (RPE) during treadmill or bicycle exercise in patients with ischemic heart disease. METHOD: 73 consecutive male patients who were referred to cardiac rehabilitation unit after taking coronary angioplasty were selected. All patients took exercise test by modified Bruce protocol and exercise intensity were prescribed by Karvonen's formula. On the first day of exercise, patients performed exercise by treadmill or bicycle with 60% heart rate reserve for 24 minutes, and on the second day of exercise, mode of exercise was switched with same intensity. On the third day, patients performed treadmill or bicycle exercise with 85% heart rate reserve for 24 minutes and also switched on the fourth day. Heart rate, blood pressure, and Borg's RPE were recorded on 2 minutes before exercise termination during all 4 days.
RESULTS
Blood pressure was higher in bicycle exercise than treadmill, and there was no significant difference in the change rate of blood pressure between 60% and 85% heart rate reserves. Myocardial oxygen demand and RPE were also higher in patients exercised on bicycle exercise than treadmill at 60% and 85% heart rate reserves. With the intensity of 85% heart rate reserve, RPE was higher in bicycle exercise (15, hard) than treadmill (13, somewhat hard).
CONCLUSION
In patient with ischemic heart disease, bicycle exercise at 85% heart rate reserve might be heavy burden during the early cardiac rehabilitation.