Author + information
- Received November 21, 2011
- Revision received February 3, 2012
- Accepted February 14, 2012
- Published online October 1, 2012.
- Anca Florian, MD⁎,
- Massimo Slavich, MD⁎,
- Pier Giorgio Masci, MD†,
- Stefan Janssens, MD, PhD‡ and
- Jan Bogaert, MD, PhD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Jan Bogaert, Department of Radiology, UZ Leuven, Herestraat 49, B-3000 Leuven, Belgium
Objectives The aim of this study was to evaluate the evolution in Q-wave expression during the first 5 years after a primary, successfully reperfused ST-segment elevation myocardial infarction (MI), using cardiac magnetic resonance (CMR) for infarct location, and to depict changes in infarct size and left ventricular remodeling over time.
Background In the absence of QRS confounders, abnormal Q waves are usually diagnostic of myocardial necrosis. It is hypothesized that Q-wave regression after MI could be related to smaller infarct sizes. Late gadolinium enhancement accurately depicts MI of any age.
Methods Forty-six MI patients underwent electrocardiography and CMR at 1 week (baseline), 4 months, 1 year, and 5 years post-infarction. Conventional CMR parameters were analyzed, and infarct presence, location, and size were assessed using late gadolinium enhancement CMR. Infarct locations were anterior or nonanterior (inferior and/or lateral), using late gadolinium enhancement CMR as a reference. For each time point, patients were classified as having a diagnostic/nondiagnostic electrocardiogram (ECG) using the European Society of Cardiology/American College of Cardiology Foundation/American Heart Association/World Heart Federation consensus criteria for previous Q-wave infarct.
Results At baseline, 11 patients (23%) did not meet the criteria for Q-wave MI. Non–Q-wave infarcts were significantly smaller than Q-wave infarcts (p < 0.0001). All anterior Q-wave infarcts (n = 17) were correctly localized, whereas in 7 of 19 nonanterior Q-wave infarcts, the location or extent of the infarct was misjudged by electrocardiography. At 4-month/1-year follow-up, in 10 patients (3 anterior/7 nonanterior), the ECG became nondiagnostic. The ECG remained nondiagnostic at 5-year follow-up. A cutoff infarct size of 6.2% at 1 year yielded a sensitivity of 89% and a specificity of 74% to predict the presence or absence of Q waves.
Conclusions The incidence of nondiagnostic ECGs for previous MI using the current European Society of Cardiology/American College of Cardiology Foundation/American Heart Association/World Heart Federation criteria is substantial and increases with time post-infarction from 23% immediately post-infarction to 44% at 5-year follow-up.
This study was funded in part by a grant from Research Foundation Flanders (G.0613.09). All authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Florian and Slavich contributed equally to this paper.
- Received November 21, 2011.
- Revision received February 3, 2012.
- Accepted February 14, 2012.
- American College of Cardiology Foundation