title: Upwardly concave ST segment morphology is common in acute left anterior descending coronary occlusion.
abstract: ST elevation (STE) in anterior precordial leads, in association with upwardly convex morphology (M) or straightM, is associated with anterior acute myocardial infarction (aAMI). Upwardly concaveM is characteristic of pseudoinfarction patterns such as early repolarization. A retrospective review was done of diagnostic electrocardiograms (EKG) of consecutive patients presenting to our Emergency Department (ED) who underwent emergent primary percutaneous intervention (PCI) and had proven left anterior descending (LAD) occlusion. If all leads from V2-V6 were upwardly concave, the EKG was classified as concaveM. If one lead was convex, the EKG had convexM. If no leads were convex and at least one was straight, it had straightM. Non-concaveM was defined as either convexM or straightM. Borderline STE was defined if the EKG did not have 2 consecutive leads with >or= 2 mm of STE. "Subtle," as opposed to "diagnostic," morphology was defined as concaveM without terminal QRS distortion. Data were analyzed with descriptive statistics. There were 37 patients identified who met the inclusion criteria and whose records were available for review. ConcaveM was found in 16 of 37 (43%), 4 with terminal QRS distortion. Measurements resulted in a classification of borderline STE in 15 of 37 (41%) (9 of whom had subtle morphology) for Rater 1 and 12 of 37 (32%) (7 of whom had subtle morphology) for Rater 2, while 19% to 24% had both "subtle" morphology and borderline ST elevation. ConcaveM, as compared with convexM or terminal QRS distortion, was associated with a shorter duration of symptoms (p < 0.05). It is concluded that concave morphology cannot be used to exclude STEMI with LAD occlusion. Many patients with LAD occlusion have borderline ST elevation with subtle morphology. Concave morphology is associated with a shorter duration of symptoms.
authors.affiliation: Department of Emergency Medicine, Hennepin County Medical Center and University of Minnesota School of Medicine, Minneapolis, Minnesota, USA.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D012189:Retrospective Studies