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Diastolic synchronized retroperfusion versus reperfusion: effects on regional left ventricular function and
Insights
Diastolic retroperfusion of the coronary sinus improved blood flow and heart muscle function in ischemic zones during coronary artery occlusion. This method offers potential as circulatory support for jeopardized myocardium.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Myocardial Ischemia Research
Background:
- Coronary artery occlusion leads to myocardial ischemia, impairing heart muscle function and blood flow.
- Effective reperfusion strategies are crucial for salvaging ischemic myocardium.
Purpose of the Study:
- To investigate the effects of diastolic synchronized retroperfusion of the coronary sinus on regional myocardial contractility and blood flow.
- To compare retroperfusion with standard coronary artery occlusion and anterograde reperfusion.
Main Methods:
- Open-chest dog model subjected to 180 minutes of coronary artery occlusion.
- Diastolic retroperfusion of the coronary sinus with arterial blood for 170 minutes.
- Assessment of regional myocardial blood flow (microspheres) and contractility (ultrasonic crystals).
Main Results:
- Retroperfusion significantly improved transmural blood flow in moderately and severely ischemic zones, with favorable endocardial redistribution.
- Regional contractility improved in moderately ischemic zones, and paradoxical bulging was reduced in severely ischemic zones.
- Functional and hemodynamic improvements were intermediate between anterograde reperfusion and sustained occlusion.
Conclusions:
- Diastolic retroperfusion of the coronary sinus demonstrates beneficial effects on regional perfusion and function in ischemic myocardium.
- Retroperfusion may serve as a valuable medical circulatory support strategy for jeopardized heart muscle during coronary occlusion.
Abstract:
The effects of 170 minutes of diastolic synchronized retroperfusion of the coronary sinus with arterial blood during 180 minutes of coronary artery occlusion on regional myocardial contractility (ultrasonic crystals) and blood flow (microspheres) were investigated in open-chest dogs. These effects were compared with those of 180 minutes of coronary occlusion and those of 170 minutes of anterograde reperfusion after 10 minutes of coronary occlusion in separate groups of dogs. Retroperfusion was able to almost restore transmural blood flow in the moderately ischemic zones and to increase it back to 47% of its preocclusion value in the severely ischemic zones with, in both zones, a favorable redistribution of flow toward the endocardium. Simultaneously, retroperfusion significantly improved segment length shortening in the moderately ischemic zones and significantly reduced the extent of paradoxical bulging in the severely ischemic zones. These partial recoveries in regional contractility and blood flow during retroperfusion were intermediate between those induced by 170 minutes of anterograde reperfusion and those of 180 minutes of coronary artery occlusion. Thus, in the presence of coronary artery occlusion, retroperfusion appears to exert a beneficial effect by improving both regional perfusion and function in the ischemic zones and may be proposed as a medical circulatory support to the jeopardized myocardium.