Do electrocardiographic changes with adenosine myocardial perfusion imaging predict ischaemia in patients with left ventricular hypertrophy?

BACKGROUND: Electrocardiographic (ECG) changes during adenosine myocardial perfusion imaging (MPI) correlate with severe coronary artery disease and the presence of collaterals. However, the significance of these changes during adenosine MPI in patients with left ventricular hypertrophy (LVH) on baseline electrocardiogram is less well understood. OBJECTIVE: To evaluate whether ECG changes on adenosine MPI predict ischaemia in patients with LVH. METHODS: We reviewed retrospectively 454 consecutive patients who had undergone adenosine MPI at our institution. The baseline electrocardiogram was reviewed to determine whether or not LVH was present. All patients were administered adenosine at 140 microg x kg x min for a total of 6 min and Tc-sestamibi was injected at 3 min into the protocol. None of the patients underwent any form of exercise during the stress test. RESULTS: Of the 146 patients with LVH, 10 had stress ECG changes suggestive of ischaemia and 40 had evidence of ischaemia on MPI. Similarly, of the 308 patients without LVH, 43 had stress ECG changes suggestive of ischaemia and 68 had ischaemia on MPI. The sensitivity and specificity of stress ECG changes in predicting ischaemia on perfusion in patients with LVH were 12.5% and 95.3%, respectively, with a positive predictive value of 50% and a negative predictive value of 74.3%. CONCLUSION: ECG changes suggestive of ischaemia in patients with LVH are very specific for ischaemia on MPI, and their significance is similar to that in patients without LVH.