Abstract 10288: Revealing the Full Meaning of Lead aVR ST Changes in ST Elevation Myocardial Infarction
Background: For acute ST elevation myocardial infarction (AMI), we previously found higher mortality with dichotomously defined aVR ST elevation. As aVR is neither an anterior nor an inferior lead, the relationship between aVR ST level and mortality is unknown and may differ according to the infarct location.
Methods: Lead aVR ST level was measured to the nearest 0.5mm on randomization and 60-minutes ECGs in 15,315 patients with normal conduction from the HERO-2 trial, with 30-day mortality as the end-point.
Results: Deeper baseline aVR ST depression (0mm, 0.5 mm, 1 mm, ≥1.5 mm) was associated with higher mortality for anterior AMI (9.8%, 13.2%, 12.8%, 16.8% respectively, trend P value <0.0001), but not for inferior AMI (6.3%, 5.6%, 6.4%, 7.2% respectively, trend P value 0.336). Resolution of aVR ST depression 60 minutes after fibrinolysis was associated with lower mortality, particularly with anterior AMI. There was a U shape relationship between mortality and baseline aVR ST level for anterior but not inferior AMI. Multivariable analysis using a neutral ST reference level showed that for anterior but not inferior AMI, aVR ST depression was associated with higher 30-day mortality. The risk was significantly increased by 42% unadjusted, 29% adjusted to ST changes in other leads, 49% further adjusted to age and prior infarctions, and 41% adjusted to all factors. In contrast, aVR ST elevation ≥1 mm was associated with higher 30-day mortality for inferior AMI but not anterior AMI.
Conclusions: Lead aVR ST depression confers a worse prognosis for anterior but not inferior AMI, while aVR ST elevation conferring a worse prognosis for inferior but not anterior AMI. The uniquely oriented lead aVR provides unique information during ST elevation AMI and its independent prognostic effect is over and above the ST changes in the other 11standard ECG leads..
- © 2010 by American Heart Association, Inc.