Relative cardiac efficiency and ST depression during progressive exercise test.
The ratio of calculated myocardial oxygen consumption to estimated oxygen uptake of the body of (MVO2/VO2) provides insight into relative cardiac efficiency. The authors investigated the relation of ST depression to the calculated MVO2/VO2 ratio during a progressive bicycle exercise test in 23 patients with good chronotropic capacity after acute myocardial infarction. ST depression of 0.2 mV or more was required at the highest exercise level. In each case, the lowest MVO2/VO2 value was, on an average, at 60.5% (SD 12.7) of the maximally tolerated work load. The magnitude (mV) and the velocity (micro V/min of ST depression measured at the exercise level after the lowest MVO2/VO2 value were significantly higher than the same parameters at the exercise level corresponding to the lowest MVO2/VO/ value. The authors believe that the lowest value of the calculated MVO2/V.O2 ratio can be regarded as a critical point which is followed by the acceleration of ST depression.
D000328:Adult; D005080:Exercise Test; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption