Relationship between late potentials and myocardial viability assessed by dobutamine echocardiography in the early postinfarction period.
BACKGROUND
In the postmyocardial infarction period, late potentials (LPs) are a sensitive marker for the occurrence of sustained ventricular tachycardia and ventricular fibrillation. The relationship between positive signal-averaged electrocardiogram (SAECG) and myocardial viability remains controversial. The aim of the present study was to assess prospectively the possible relationship between LPs and myocardial viability detected by dobutamine stress echocardiography (DSE) in the early period after myocardial infarction (AMI), before hospital discharge.


METHODS
Ninety-nine patients with AMI were included prospectively in the study. The mean age was 58 +/- 11 years, 17 were women and 82 were men. All patients had SAEG and DSE, and 94 had coronary angiography before hospital discharge.


RESULTS
In the overall population, presence of viability was demonstrated in fewer patients with LPs [37 of 70 (52%)] than absence of viability [18 of 29 (62%)] but the difference did not reach statistical significance. In the subgroup of patients with left ventricular ejection fraction (LVEF) lower than 40%, at higher risk of arrhythmias, the presence of viability was associated with the absence of LPs: 80% of the patients without LPs had viability by DSE (P < 0.01) and only 35% of patients with LPs had viability by DSE (not significant).


CONCLUSIONS
In patients with an acute myocardial infarction and with low ejection fraction (<40%), the absence of LPs is related to the presence of viable myocardium as assessed by DSE early after the acute event. These data also suggest that myocardial viability is not the substrate for LPs in this population.
Cosyns
Bernard
B
Cardiology Department, Academisch Ziekenhuis, Vrije Universiteit Brussel, Belgium. cardiohbw@swing.be
Akseki
Elif
E
Van Camp
Guy
G
Schoors
Danny
D
Liebens
Isabelle
I
Plein
Danièle
D
Vandenbossche
Jean-Luc
JL
Franken
Philippe
P
D000318:Adrenergic beta-Agonists; D000368:Aged; D004280:Dobutamine; D025401:Echocardiography, Stress; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D018570:Risk Assessment; D013318:Stroke Volume
D000318:Adrenergic beta-Agonists; D004280:Dobutamine