Lack of pathologic Q waves: a specific marker of viability in myocardial hibernation

Clin Cardiol. 2008 Aug;31(8):372-7. doi: 10.1002/clc.20244.

Abstract

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.

MeSH terms

  • Coronary Angiography
  • Coronary Artery Disease / physiopathology
  • Dobutamine
  • Echocardiography
  • Echocardiography, Stress
  • Electrocardiography*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Stunning / diagnostic imaging
  • Myocardial Stunning / physiopathology*
  • Radionuclide Imaging
  • Sensitivity and Specificity
  • Thallium Radioisotopes
  • Tissue Survival / physiology*

Substances

  • Thallium Radioisotopes
  • Dobutamine