Does chronic ST segment elevation following Q wave myocardial infarction exclude tissue viability?
OBJECTIVE
Electrocardiographic (ECG) ST segment elevation lasting 2 or more weeks following Q wave myocardial infarction has been associated with 'ventricular aneurysm' and absence of tissue viability. Regional systolic dysfunction may reflect either viable myocardium or scar. Positron emission-tomographic (PET) imaging can distinguish viable from nonviable tissue. We hypothesized that patients with chronic ST segment elevation after Q wave infarction might demonstrate salvageable myocardium in the infarct region.


METHODS
The ECGs of 1,229 sequential patients undergoing PET scans for viability assessment were reviewed by an electrocardiographer to identify individuals with chronic anteroseptal Q wave infarctions with persistent ST segment elevation exceeding 1 mV. Patients with QRS duration longer than 0.14 ms or rhythm other than sinus were excluded. Viability was considered present if either a reversible stress-induced perfusion defect (ischemia) or a resting perfusion-metabolism mismatch (hibernation) was identified.


RESULTS
Anteroseptal ECG Q wave infarction was identified in 132 subjects (74% male, age 61 +/- 12 years). Chronic ST segment elevation was present in 84 subjects (64%) and absent in 48. Baseline clinical characteristics and left ventricular systolic function were similar in both groups. 63% of those with and 56% of those without chronic ST elevation had viable myocardium. No relationship was noted between chronic ST segment elevation and the presence or absence of myocardial viability.


CONCLUSIONS
Chronic ST segment elevation after anteroseptal Q wave myocardial infarction does not exclude myocardial viability in the 'infarct zone'. Evaluation of residual tissue viability is indicated to assess the benefit of revascularization in patients with Q wave infarction and chronic ST segment elevation.
Saber
Walid
W
Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, Ohio 44053, USA. wdsaber@yahoo.com
Nishime
Erna Obenza
EO
Brunken
Richard C
RC
Apperson-Hansen
Carolyn
C
Mills
Roger M
RM
D000368:Aged; D004562:Electrocardiography; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D017682:Myocardial Stunning / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D019275:Radiopharmaceuticals; D012307:Risk Factors; D014022:Tissue Survival; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18