TY - JOUR
T1 - Analysis of Postsystolic Myocardial Thickening Work in Selective Myocardial Layers During Progressive Myocardial Ischemia
AU - Wang, Jianwen
AU - Urheim, Stig
AU - Korinek, Josef
AU - Abraham, Theodore P.
AU - McMahon, Eileen M.
AU - Belohlavek, Marek
N1 - Funding Information:
Supported by the American Heart Association Established Investigator Award 0245016N and in parts by the National Institutes of Health Grant HL 68573. Additional funding and technical support was provided by Siemens Medical Solutions.
PY - 2006/9
Y1 - 2006/9
N2 - Background: Myocardial function is transmurally heterogeneous. Postsystolic work may functionally reflect ischemic but viable myocardium. We calculated systolic and postsystolic regional myocardial work index (RMWi) in subendocardial and subepicardial layers of myocardium supplied by a slowly occluding coronary artery. Methods: Progressive stenosis of the left anterior descending coronary artery lasting 11 ± 5 days (end point) was induced in 10 dogs, and pressure-strain loops were obtained from subendocardial and subepicardial layers of apical and middle anterior segments by intracardiac ultrasound. Results: At baseline, the RMWi was significantly higher (P < .05) in the subendocardial layer. At the end point, there was no significant change in the RMWi in ischemic myocardium; however, the postsystolic RMWi was higher (P < .05) in the subendocardial layer and accompanied a decrease in subendocardial myocardial blood flow, although viability was largely maintained. Conclusion: A significant subendocardial postsystolic RMWi at rest suggests an impending ischemic injury in coronary artery disease when segmental function is still preserved.
AB - Background: Myocardial function is transmurally heterogeneous. Postsystolic work may functionally reflect ischemic but viable myocardium. We calculated systolic and postsystolic regional myocardial work index (RMWi) in subendocardial and subepicardial layers of myocardium supplied by a slowly occluding coronary artery. Methods: Progressive stenosis of the left anterior descending coronary artery lasting 11 ± 5 days (end point) was induced in 10 dogs, and pressure-strain loops were obtained from subendocardial and subepicardial layers of apical and middle anterior segments by intracardiac ultrasound. Results: At baseline, the RMWi was significantly higher (P < .05) in the subendocardial layer. At the end point, there was no significant change in the RMWi in ischemic myocardium; however, the postsystolic RMWi was higher (P < .05) in the subendocardial layer and accompanied a decrease in subendocardial myocardial blood flow, although viability was largely maintained. Conclusion: A significant subendocardial postsystolic RMWi at rest suggests an impending ischemic injury in coronary artery disease when segmental function is still preserved.
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U2 - 10.1016/j.echo.2006.04.023
DO - 10.1016/j.echo.2006.04.023
M3 - Article
C2 - 16950464
AN - SCOPUS:33748041128
SN - 0894-7317
VL - 19
SP - 1102
EP - 1111
JO - Journal of the American Society of Echocardiography
JF - Journal of the American Society of Echocardiography
IS - 9
ER -