[Beneficial effects of ischemic preconditioning on myocardial no-reflow in a mini-swine model of acute myocardial infarction and reperfusion].

Abstract

OBJECTIVE:

To evaluate the effects of ischemic preconditioning (IPC) on myocardial no-reflow in a mini-swine model of acute myocardial infarction (AMI) and reperfusion.

METHODS:

Twenty-four mini-swines were randomized into 3 study groups: 8 in control, 8 in IPC and 8 in sham-operated. Animals in the former two groups were subjected to 3 hours of coronary occlusion followed by 1 hour of reperfusion. Data on hemodynamics and coronary blood flow volume (CBV) were collected, and the area of no-reflow (ANR) was evaluated with both myocardial contrast echocardiography (MCE) in vivo and pathological means. Necrosis area (NA) was measured with triphenyltetrazolium chloride (TTC) staining.

RESULTS:

In control group, left ventricular systolic pressure (LVSP), the maximum change rate of left ventricular pressure rise and fall (+/-dp/dtmax) and cardiac output (CO) significantly declined (P < 0.05, P < 0.01), while left ventricular end-diastolic pressure (LVEDP) significantly increased at the end of 3 hours of left anterior descending coronary artery occlusion (both P < 0.01), with +/-dp/dtmax further significantly declined (both P <0.05) at 1 hour of reperfusion. In IPC group, LVSP, +/-dp/dtmax, CO and LVEDP significantly recovered at 1 hour of reperfusion, compared with those in control group. In IPC group, the coronary ligation area was similar on both MCE in vivo and pathological evaluation (P > 0.05), and ANR was both also similarly as high as (16.4 +/- 2.24) % and (17.5 +/- 2.87) %, respectively, with final necrosis area (NA) reaching (78.4 +/- 3.62) %. In IPC group, ANR and final NA were significantly lower than those in control group (P < 0.05, P < 0.01). In the control group, coronary blood flow volumn immediately after release of 3 hours occlusion and at 1 hour of reperfusion were significantly lower than the baseline (both P < 0.01). In IPC group, coronary blood flow volumn were significantly higher than those in the control group (both P < 0.01).

CONCLUSION:

IPC is effective to prevent myocardial no-reflow, improve left ventricular function and decrease infarct area.

• Authors: Jing-Lin Zhao, Yue-Jin Yang, Shi-Jie You, Zhi-Cheng Jing, Yong-Jian Wu, Wei-Xian Yang, Liang Meng, Yi Tian, Ji-Lin Chen, Run-Lin Gao, Zai-Jia Chen
• Journal: Zhongguo yi xue ke xue yuan xue bao. Acta Academiae Medicinae Sinicae (Zhongguo Yi Xue Ke Xue Yuan Xue Bao) Vol. 27 Issue 4 Pg. 486-90 (Aug 2005) ISSN: 1000-503X [Print] China
• PMID: 16178445 (Publication Type: Journal Article)

Topics

• Animals
• Blood Flow Velocity
• Coronary Circulation (physiology)
• Echocardiography
• Hemodynamics
• Ischemic Preconditioning
• Myocardial Infarction (diagnostic imaging, physiopathology)
• Myocardial Reperfusion (methods)
• Myocardial Reperfusion Injury (diagnostic imaging, physiopathology, prevention & control)
• Random Allocation
• Swine
• Swine, Miniature