[Diagnostic and prognostic value of ST segment depression greater than or equal to 3 mm during exercise testing]

This study was undertaken to assess the diagnostic and prognostic value of ST depression equal to or more than 3 mm during exercise stress testing (EST). Out of 4050 EST performed over an 8 year period, 128 patients (3,2%) had this degree of ST depression. These changes were observed in leads V4 V6 in 92% of cases. Coronary angiography was performed in 56 patients: all had significant coronary artery disease (greater than 50% stenoses) with 50% three vessel, 30% two vessel and only 20% single vessel disease; all patients had at least one severe stenosis (greater than 75%) of a main coronary artery. The predictive value of EST was therefore 100% in the 56 patients undergoing coronary angiography. Angina or ventricular extrasystoles during EST or greater than 5 mm ST depression were predictive of multiple vessel disease. The following correlations were observed between EST and the extent of coronary artery disease: maximal heart rate and systolic pressure were lower, ischemic changes appeared sooner (less than 2 min) and lasted longer during the recovery phase (greater than 7 min) in patients with multiple vessel disease. The 5 year prognosis was studied in 58 patients; it was poor (death or infarction) in 31 cases (53%). The following factors were associated with a poor prognosis: low maximal heart rate and systolic blood pressure, early ischemic changes and frequent ventricular extrasystoles on EST; on the other hand, the development of anginal pain during EST was not of significant prognostic value in this series. ST depression greater than 3 mm on EST is rare.(ABSTRACT TRUNCATED AT 250 WORDS)