Abstract
Purpose: This study aimed to identify the correlation between aerobic threshold（ AT） and
cardiopulmonary response at the start of exercise in patients with myocardial infarction（ MI）.
Subjects and Methods: Thir ty-one male patients with MI underwent a sub-maximal
cardiopulmonary exercise test with expiratory gas analysis to determine their peak oxygen
uptake （V ・O2） level, using Ramp protocol.
Results: The patients demonstrated an extended time constant（ TC） and decline in AT in this
study. Extended TC suggested impaired cardiac function due to reduced left ventricular
ejection fraction （LVEF）, as well as an LVEF of 59.8％ on average. However, there was no
significant correlation between TC and AT. Pearson product-moment correlation coefficients
were 0.56 between AT and area under the oxygen uptake curve （V ・O2AUC）, –0.22 between TC
and V ・O2AUC, and –0.23 between AT and TC.
Conclusion: V ・O2AUC is representative of oxygen utilization and is correlated with AT in
patients with MI.
