Exercise-induced T-wave normalization predicts recovery of regional contractile function after anterior myocardial infarction.
OBJECTIVE
We investigated the ability of T-wave pseudonormalization and ST-segment elevation, which are demonstrated in infarct-related leads during submaximal exercise testing, to predict late recovery of contractile function.


METHODS
We studied 88 consecutive patients (73 males, mean age 59 +/- 8 years) with anterior infarction, persistent T-wave inversion and a documented lesion of the proximal segment of the left anterior 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. Submaximal (75% of maximal predicted heart rate) exercise testing was performed in 80 patients 2 weeks after myocardial infarction following discontinuation of treatment.


RESULTS
During exercise testing, 59 of the 88 patients showing negative T-waves on the resting electrocardiogram exhibited pseudonormalization (group A) in at least three adjacent precordial leads, whilst 29 (group B) did not. Patients of group A more frequently 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 concomitant presence of ST-segment elevation and T-wave normalization showed the highest positive predictive value for left ventricular function recovery (100%).


CONCLUSIONS
T-wave normalization induced by submaximal 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 contractile function.
Pizzetti
G
G
Department of Cardiology, Istituto Scientifico H.S.Raffaele, Milano, Italy.
Montorfano
M
M
Belotti
G
G
Margonato
A
A
Ballarotto
C
C
Chierchia
S L
SL
D000368:Aged; D017023:Coronary Angiography; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014463:Ultrasonography