The Exercise Test and Prognosis of Coronary Heart Disease

SIGNIFICANCE and prognostic value of the exercise test in coronary heart disease remain controversial.Robb and associates1 found significantly higher rates of death and occlusion in those with a positive test and stated that a negative response to the double two-step exercise test excludes, for practical purposes, the presence of latent coronary insufficiency and clinically significant narrowing of the coronary arteries.Le- peschkin2 reported that a completely normal electrocardiographic response to the double Master exercise test indicates with great probability that no major coronary stenosis is pres- ent, or, if present, it is well compensated by collateral circulation.Wood and associates3 permitted 100 patients with classical angina pectoris to exercise until symptoms developed and obtained an isehemic response in 88 per cent.Scherf4 stated that it is apparently im- possible to exclude false-negative tests and that any conclusion as to prognosis, based on the outcome of an exercise test, is unjustified.The type of response to exercise in which the S-T segment is depressed 0.5 mm. or more below the P-R or P-Q junction in a horizontal or sagging course has been described as significant of myoeardial isehemia by Wood and associates3 and by Myers and Talmers.5 Robb and associates1 found this to be the best and only unequivocable criterion for a positive test.Brody6 examined 756 business executives free of clinical coronary heart disease and found 23 with this ischemic type of response.Definite coronary artery disease later developed in 70 per cent of these 23 men.Myers and Talmers,5 Robb and associates,1 and Brody6 all found that S-T junctional depres- sion, if deep and not due to tachycardia, could indicate myocardial ischemia in some cases.