[Increase in the amplitude of R waves in exertion: a bad diagnostic criterion for coronary insufficiency].

91 symptomatic patients were given an exercise test on a bicycle ergometer and a coronary arteriography test within a delay of 31 days. Of the patients (13 females and 78 males), 35 presented with a normal coronary arteriography and 56 presented with a pathological coronary arteriography (16 of whom had a history of myocardial infarction). We have studied the diagnostic value of several parameters taking into account changes in R waves upon exercise in V4 V5 V6 and changes in S waves in V1 V2. The most reliable parameter is also the easiest to calculate: it is considered positive when the R wave measured in V5 increases or does not change in the minute following cessation of exercise, as compared with the reference trace; it is considered negative when the R wave decreases. This criterion has a specificity of 60 per cent and a sensitivity of 71.4 per cent, and its diagnostic value is not improved by exclusion of patients with a history of infarction, or by exclusion of treated subjects or females. The horizontal or downsloping depression of the ST-segment has the same sensitivity but a better specificity (74%). Literature data are contradictory: some authors report that changes in the R wave upon exercise have a better predictive value than changes in the ST-segment, whereas an equal number of authors consider that the ST-segment is more informative. These differences of opinion result from methodological disparities and the large number of physiopathological elements affecting the amplitude of R waves.