Significance of New, Isolated T-wave Inversion in Multiple Electrocardiogram Leads with Regadenoson Injection in Patients with Normal Myocardial Perfusion Imaging: An Observational Report of 5 Consecutive Cases

INTRODUCTION: The pharmacologic (regadenoson) stress myocardial perfusion imaging (MPI) is used widely in patients who cannot exercise for detecting coronary artery disease (CAD). The interpretation of these studies depends primarily on the imaging results because the sensitivity of electrocardiograms (ECG) in this setting is poor. Prior study showed that effects of regadenoson on ST-segment occurred infrequently and had low sensitivity for detecting CAD. The significance of T-wave inversion in multiple ECG leads without ST-segment depression with regadenoson injection in patients with normal MPI is described and reported. METHODS: ECGs were reviewed retrospectively in 64 patients who had regadenoson MPI and coronary angiography for evaluation of CAD from June 1, 2016 to August 31, 2018. Five cases were identified with new, isolated T-wave inversion in multiple ECG leads. RESULTS: All five cases had new and isolated T-wave inversion in multiple leads without ST segment depression with regadenoson injection and normal MPI. At coronary angiography, three of the five cases showed obstructive coronary artery disease who received coronary percutaneous intervention. One case had nonobstructive coronary artery disease and one had a normal coronary artery. CONCLUSIONS: Despite nonspecific ST-T changes on baseline ECGs and normal MPI in all patients, three of five cases had obstructive CAD by coronary angiography. New, isolated T-wave inversion in multiple ECG leads with regadenoson injection were observed in our patients with normal MPI. These ECG findings may be associated with false negative MPI. Therefore, careful observation and scrutiny of all ECG changes, especially new, isolated T-wave inversion in multiple ECG leads during regadenoson MPI is advisable to identify potential obstructive CAD despite normal MPI findings.