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Does the presence of Q waves on ECG indicate myocardial scar on cardiac MRI?

  • Gurjit Singh
  • Leonidas Tzogias
  • Mario Njeim
  • Milan V Pantelic
  • Khalid Nour
  • Mouaz H Al-Mallah
Open Access
Poster presentation
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Keywords

Cardiac Magnetic Resonance Anterior Segment Cardiac Magnetic Resonance Imaging Clinical Reason Myocardial Necrosis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Background

Pathologic Q waves are the classic ECG sign of myocardial infarction. Prior studies have shown cardiac MRI is a more sensitive tool to detect myocardial necrosis. However, it is unclear whether pathologic Q waves on ECG always correlate with ischemic pattern of delayed enhancement. We tested the hypothesis that Q waves always indicate the presence of myocardial scaring on contrast enhanced cardiac Magnetic resonance imaging.

Methods

We included 41 (25% females) consecutive patients with pathologic Q waves on ECG who underwent contrast enhanced cardiac MRI (1.5 T) for various clinical reasons. Imaging protocols included cine SSFP sequence and post double dose contrast delayed imaging. Q waves were considered pathologic if the total Q wave voltage is more than one third of the QR voltage. Left ventricular myocardial scar was evaluated qualitatively using the AHA recommended 17 segment model by 2 readers who were blinded to the clinical and ECG data.

Results

A total of 29/41 (69%) patients had evidence of myocardial scar in coronary pattern, 18 (44%) of which were transmural. The presence of a Q only pattern (absence of R or S waves) did not improve the accuracy of ECG in identifying myocardial delayed enhancement on MRI. However, Q waves only modestly localized the scar. Anterior Q waves (64%) have the best correlation with the presence of scar in the anterior segments with lateral and inferior being 41% and 40% respectively. In addition, the Q only pattern did not improve the localizing accuracy of ECG.

Conclusion

The presence of pathologic Q waves on ECG is not always associated with the presence of prior myocardial infarction on cardiac MRI. In addition, Q waves appear to modestly correlate with the location of the prior MI. Further studies should evaluate the potential causes of pathologic Q waves in patients without prior myocardial infarction.

Copyright information

© Singh et al; licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd.

Authors and Affiliations

  • Gurjit Singh
    • 1
  • Leonidas Tzogias
    • 1
  • Mario Njeim
    • 1
  • Milan V Pantelic
    • 1
  • Khalid Nour
    • 1
  • Mouaz H Al-Mallah
    • 1
  1. 1.Henry Ford HospitalDetroitUSA

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