Purpose: To evaluate, in patients with chest pain, the diagnostic value of ST elevation (STE) in lead aVR during stress testing prior to (99m) Tc-sestamibi scanning correlating ischaemic territory with angiographic findings.
Methods: Consecutive patients attending for (99m) Tc-sestamibi myocardial perfusion imaging (MPI) completed a treadmill protocol. Peak exercise ECGs were coded. STE >or=0.05 mV in lead aVR was considered significant. Gated perfusion images and findings at angiography were assessed.
Results: STE in lead aVR occurred in 25% (138/557) of the patients. More patients with STE in aVR had a reversible defect on imaging compared with those who had no STE in aVR (41%, 56/138 vs 27%, 114/419, p=0.003). Defects indicating a left anterior descending artery (LAD) culprit lesion were more common in the STE in aVR group (20%, 27/138 vs 9%, 39/419, p=0.001). There was a trend towards coronary artery stenosis (>70%) in a double vessel distribution involving the LAD in those patients who had STE in aVR compared with those who did not (22%, 8/37 vs 5%, 4/77, p=0.06). Logistic regression analysis demonstrated that STE in aVR (OR 1.36, p=0.233) is not an independent predictor of inducible abnormality when adjusted for STD >0.1 mV (OR 1.69, p=0.026). However, using anterior wall defect as an end-point, STE in aVR (OR 2.77, p=0.008) was a predictor even after adjustment for STD (OR 1.43, p=0.281).
Conclusion: STE in lead aVR during exercise does not diagnose more inducible abnormalities than STD alone. However, unlike STD, which is not predictive of a territory of ischaemia, STE in aVR may indicate an anterior wall defect.