Author + information
- Received January 18, 2006
- Revision received July 14, 2006
- Accepted July 17, 2006
- Published online November 21, 2006.
- Jonathan Chan, MB, BS, MRCP (UK),
- Lizelle Hanekom, MB, BS,
- Chiew Wong, MB, BS, FRACP,
- Rodel Leano, BSc,
- Goo-Yeong Cho, MD, PhD and
- Thomas H. Marwick, MB, BS, PhD, FACC⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Thomas Marwick, University of Queensland, Department of Medicine, Princess Alexandra Hospital, Ipswich Road, Brisbane, Qld 4102, Australia.
Objectives This study sought to differentiate the transmural extent of infarction (TME) by assessment of the short-axis and long-axis function of the left ventricle (LV) using 2-dimensional (2D) strain.
Background The differentiation of subendocardial infarction from transmural infarction has significant prognostic and clinical implications.
Methods Contrast-enhanced magnetic resonance imaging (CE-MRI) and dobutamine stress echocardiography (DBE) were performed in 80 patients (age 63 ± 10 years) with chronic ischemic LV dysfunction. Myocardial function was assessed in the short axis at the midventricular level using peak strain rate (SR) and strain (S) in circumferential and radial dimensions, and was assessed in the long axis using longitudinal SR and S. Wall motion analysis was performed during DBE to assess for contractile reserve.
Results Transmural infarct segments had lower circumferential S (−10.7 ± 6.3) and SR (−1.0 ± 0.4) than subendocardial infarcts (S: −15.4 ± 7.0, p < 0.0001; SR: −1.4 ± 0.8, p = 0.02) and normal myocardium (S: p < 0.0001; SR: p < 0.0001). Transmural and subendocardial infarct segments had similar radial S and SR. Subendocardial infarct segments showed significant reduction of longitudinal S (−13.2 ± 5.6) and SR (−0.91 ± 0.45) compared with normal myocardium (S: −17.8 ± 5.4, p < 0.0001; SR: −1.1 ± 0.41, p < 0.0001), but there were no significant differences between subendocardial and transmural infarct segments (p = 0.09). Wall motion analysis by DBE could not identify subendocardial infarction on CE-MRI (TME 1% to 50%: DBE scar 38%, DBE viable 38%, DBE ischemic 24%, p = NS).
Conclusions The combined assessment of long-axis and short-axis function using 2D strain may be used to identify TME.
Supported in part by a project grant (210217) from the National Health and Medical Research Council, Canberra, Australia.
- Received January 18, 2006.
- Revision received July 14, 2006.
- Accepted July 17, 2006.
- American College of Cardiology Foundation