Exercise heart rate/ST segment relation in coronary artery disease.

Exercise heart rate/ST segment relation in coronary artery disease Sir, Dr Elamin's paper (1982; 48: 311-20) describes a possibly accurate method of diagnosing coronary artery disease and predicting its severity in terms of the number of diseased vessels: this method is based on the calculation of the maximal ST segment/heart rate slope during exercise. In 1970 we first reported that in many patients with coronary artery disease a linear relation existed between the magnitude of exer- cise induced ST segment depression and indices of myocardial oxygen requirement'; we also indicated that the slope of this relation varied between patients, but since we had no angiographic data we could only speculate on the factors influencing this slope. In later studies we have shown that this relation could be modified by several therapeutic interventions.24