Lack of Pathologic Q Waves: A Specific Marker of Viability in Myocardial Hibernation

Background The present study evaluates the lack of Q waves on the electrocardiogram (ECG) in the prediction of myocardial viability compared with dobutamine stress echocardiography (DSE) and rest‐redistribution thallium‐201 (Tl‐201) scintigraphy. Hypothesis The lack of pathologic Q waves (NoQ) may be a readily available and specific marker for the presence of viability. Methods Sixty four patients with stable coronary artery disease (CAD) and ventricular dysfunction underwent rest ECG, DSE, and Tl‐201 scintigraphy before revascularization, and a repeat rest 2‐Dimensional (2‐D) echocardiogram more than 3 mo later. Results Total viability at baseline (% of total segments) was higher in the NoQ group by Tl‐201 scintigraphy (87 ± 19% versus 70 ± 20%, p = 0.008) and by DSE (81 ± 20% versus 65 ± 24%, p = 0.013). As expected, the sensitivity of NoQ waves was low in predicting recovery of function (23%), and inferior to Tl‐201 (82%) and DSE (84%) (p<0.08). However, specificity of NoQ waves for predicting recovery of global function was high (72%); higher than Tl‐201 (50%) and DSE (45%). Positive predictive values were comparable among all modalities. Results were similar if the data were analyzed regionally for viability. Conclusion Lack of pathologic Q waves is a specific and readily available marker of myocardial viability in patients with chronic CAD, which should alert the clinician for myocardial hibernation. Copyright © 2008 Wiley Periodicals, Inc.