[Correlation between the ST/heart rate slope and the severity of coronary disease in inferior infarcts. A new criterion of positivity of the ergometric test].

We reviewed a group of 80 patients who had bicycle exercise stress testing and cardiac catheterization: 60 patients with known coronary artery disease (CAD) had a remote myocardial infarction, anterior, inferior, Q and no Q wave (post MI), 20 patients evaluated for suspected CAD resulted to have normal coronary arteries or lesions less than 50%. Patients were divided into three groups according to the extent of CAD. Group I with anatomically or functionally high risk CAD: left main (LM) stenosis greater than or equal to 50%, 3 vessels CAD greater than or equal to 70%, proximal left anterior descending stenosis (PLAD) greater than or equal to 90% with another vessel CAD; group II with one or two vessels CAD greater than or equal to 70%; group III with no or insignificant CAD. Linear regression analysis of the heart rate (HR)--related change in ST segment depression (ST/HR slope) was compared with six conventional electrocardiographic exercise test criteria to evaluate whether ST/HR slope can identify with improved accuracy group I. When all 80 patients are assessed together, ST/HR slope greater than or equal to 60 mm/beat/min 10(3) compared with standard electrocardiographic criteria failed to discriminate significantly between high-risk CAD (group I) and less extensive (group II) or insignificant CAD (group III). When only Q wave inferior post MI are considered, ST/HR slope greater than or equal to 60 mm/beat/min. 10(3) compared with ST segment depression greater than or equal to 1 mm identifies group I with 90% +/- 4 versus 75% +/- 6 overall predictive accuracy (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)