Left ventricular function during isometric : hand grip and cold stress in normal sub jects RODERICK

Both isometric exercise and cold stress have been suggested as alternatives to dynamic exercise for the detection of obstructive coronary artery disease. A non-imaging nuclear probe was used to measure left ventricular ejection fraction and relative left ventricular volumes continuously during both of these stress tests in 24 normal subjects. There was a significant fall in left ventricular ejection fraction within 15 seconds of subjects starting a two minute isometric hand grip test at 50% maximal voluntary contraction, with a mean (SE) maximal fall of 10% (1 8) after 90 seconds. During two minutes immersion of the hand and wrist in iced water left ventricular ejection fraction fell significantly within 30 seconds with a mean maximal fall of 7% (1 -7) after one minute. Nine subjects underwent repeat tests under identical conditions approximately two weeks later. The standard error of the change in ejection fraction on two occasions was 5 4% at