EXERCISE-INDUCED T-WAVE NORMALIZATION PREDICTS RECOVERY OF REGIONAL CONTRACTILE FUNCTION AFTER ANTERIOR MYOCARDIAL-INFARCTION

Aims We investigated the ability of T-wave pseudonormalization and ST- segment elevation, which are demonstrated in infarct-related leads dur ing submaximal exercise testing, to predict late recovery of contracti le function. Methods We studied 88 consecutive patients (73 males, mea n age 59+/-8 years) with anterior infarction, persistent T-wave invers ion and a documented lesion of the proximal segment of the left anteri or descending coronary artery. They all underwent 2D-echocardiography on admission, 4 weeks as well as 6 months after myocardial infarction to evaluate the dysfunction score and the ejection fraction. Submaxima l (75% of maximal predicted heart rate) exercise testing was performed in 80 patients 2 weeks after myocardial infarction following disconti nuation of treatment. Results During exercise testing, 59 of the 88 pa tients showing negative T-waves on the resting electrocardiogram exhib ited pseudonormalization (group A) in at least three adjacent precordi al leads, whilst 29 (group B) did not. Patients of group A more freque ntly exhibited an early creatine kinase peak (41% vs 24%, P<0.05) and residual angiographic perfusion (97% vs 69%, P<0.05). The dysfunction score did not change in group B (from 19+/-7 to 22+/-4), but decreased in group A (from 18+/-4 to 11+/-6, P<0.05). The ejection fraction was similar in the two groups on admission (group A: 48+/-7%, group B: 45 +/-10%), but was significantly different at 4-week (52+/-99 vs 42+/-11 %, P<0.05) and 6-month follow-up (58+/-9 vs 44+/-10%, P<0.01). The con comitant presence of ST-segment elevation and T-wave normalization sho wed the highest positive predictive value for left ventricular functio n recovery (100%). Conclusions T-wave normalization induced by submaxi mal exercise test is frequently associated with residual perfusion to the infarct area and predicts progressive improvement in regional wall motion, especially if associated with ST-segment elevation. Therefore , these electrocardiographic findings may be used as easily obtainable markers of residual viability that predict late recovery in contracti le function.