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.


OBJECTIVE
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.


CONCLUSIONS
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.
Jeon
Hui-Kyung
HK
Department of Cardiology, The Methodist Hospital, Houston, Texas, USA.
Shah
Gopi A
GA
Diwan
Abhinav
A
Cwajg
Jucylea M
JM
Park
Tae-Ho
TH
McCulloch
Marti L
ML
Zoghbi
William A
WA
D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000503:physiopathology; D004280:Dobutamine; D004452:Echocardiography; D025401:Echocardiography, Stress; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017682:Myocardial Stunning / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D014022:Tissue Survival / Q000502:physiology*
D013794:Thallium Radioisotopes; D004280:Dobutamine