Journal of Applied Physiology, Vol 40, Issue 4 611-618, Copyright © 1976 by American Physiological Society
Maximum exercise tests on "postcoronary" patients
T. Kavanagh and R. J. Shephard
The maximum oxygen intake has been measured directly (uphill treadmill
walking) in 36 patients following recovery from myocardial infarction.
These were selected as follows: 15 consecutive new entrants to an exercise
program that is currently accepting about one-sixth of the total reported
myocardial infarction hospital admissions in metropolitan Toronto (group
A), 12 patients not responding well to training (group B), and 9 patients
now running substantial distances (group C). The only clinical
complications were two episodes of ventricular tachycardia. Twenty patients
reached an oxygen plateau, and in group C, the maximum heart rate (170/min)
reached Scandinavian norms, with a maximum oxygen intake (2.63 +/- 0.35
1/min STPD, 36.9 +/- 4.8 ml/kg-min STPD) as in healthy men of the same age.
The rate of adaptation to a progressive submaximum test was such that
comparable Astrand nomogram predictions of VO2max were obtained from data
in the 3rd and 5th min at the third load. Predictions generally agreed
closely with directly measured values. It may be concluded that in patients
who have recovered sufficiently to enter an exercise rehabilitation program
1) predictions of VO2max have about the same accuracy (+/-10) as in healthy
subjects, and 2) direct measurements can often be pursued to an "oxygen
plateau" without due risk.
