Resolution of late potentials with improvement in left ventricular systolic function in patients with first acute myocardial infarction.
BACKGROUND
Ventricular late potentials predict subsequent arrhythmic events and sudden death in postinfarction patients. Late potentials are recorded in the infarcted area, but it should be pointed out that they probably represent micropotentials in the area of delayed conduction found among isolated areas of scar tissue and normal myocardium.


OBJECTIVE
The study was undertaken to investigate the relationship between chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, and late potentials in 38 patients with a first myocardial infarction.


METHODS
The patients were divided into two groups, one with (Group 1) and one without (Group 2) resolution of late potentials recorded by signal-averaged electrocardiogram at 6 months after onset of myocardial infarction. We investigated the clinical, echocardiographic, and signal-averaged electrocardiographic characteristics of Groups 1 and 2.


RESULTS
In the chronic phase of myocardial infarction, a higher incidence of patency of the infarct-related artery and an improvement of wall motion score were found in Group 1, and left ventricular ejection fraction was better preserved in Group 1 than in Group 2.


CONCLUSIONS
These results suggest that the resolution of late potentials was influenced by the improvement of left ventricular systolic function and patency of the infarct-related artery. We concluded that chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, might be the substrate that generated late potentials.
Masui
A
A
Second Department of Internal Medicine, Kansai Medical University, Osaka, Japan.
Tamura
K
K
Tarumi
N
N
Kamihata
H
H
Karakawa
M
M
Takehana
K
K
Sugiura
T
T
Iwasaka
T
T
Inada
M
M
D000200:Action Potentials / Q000502:physiology*; D001145:Arrhythmias, Cardiac / Q000175:diagnosis; D006328:Cardiac Catheterization; D015331:Cohort Studies; D017023:Coronary Angiography; D003645:Death, Sudden; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017682:Myocardial Stunning / Q000000981:diagnostic imaging / Q000503:physiopathology; D011237:Predictive Value of Tests; D013318:Stroke Volume; D013599:Systole / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*