Related Experiment Video
Updated: Aug 14, 2026
Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion
Published on: December 10, 2020
Does intermittent coronary perfusion offer greater myocardial protection than continuous aortic cross-clamping?
Insights
Intermittent coronary perfusion offers no myocardial protection advantage over continuous aortic cross-clamping during cardiac surgery. Both methods resulted in similar metabolic and contractile function outcomes after ischemic arrest.
Area of Science:
- Cardiovascular Surgery
- Cardiac Anesthesia
- Myocardial Protection
Background:
- Debate exists regarding intermittent coronary perfusion versus continuous aortic cross-clamping for cardiac procedures.
- Myocardial protection strategies during ischemic arrest are critical for patient outcomes.
Purpose of the Study:
- To compare the myocardial protective effects of intermittent coronary perfusion against continuous aortic cross-clamping.
- To evaluate metabolic and contractile function of the myocardium under different ischemic arrest strategies.
Main Methods:
- Utilized an isovolumic ventricular balloon model and "stop-freeze" biopsy techniques in 46 dogs.
- Compared 60 minutes of continuous ischemic arrest with four 15-minute ischemic intervals followed by 5-minute reperfusions.
- Assessed myocardial contractility (LV dp/dt max, length-tension, force-velocity) and metabolism (adenine nucleotides, creatine phosphate, glycogen).
Main Results:
- No significant differences were observed in myocardial metabolic parameters or contractile function between the two groups.
- Creatine phosphate levels returned to normal, while adenosine triphosphate and glycogen showed only partial regeneration during reperfusion.
- Both techniques yielded comparable outcomes regarding myocardial preservation.
Conclusions:
- Five minutes of coronary reperfusion between ischemic episodes does not provide superior intraoperative myocardial protection compared to continuous aortic cross-clamping.
- Current strategies for managing ischemic arrest during cardiac surgery show similar efficacy in preserving myocardial function.
Abstract:
There has been considerable controversy concerning the relative merits of intermittent coronary perfusion vs. continuous aortic cross-clamping for cardiac procedures requiring ischemic arrest. Using the isovolumic ventricular balloon model and "stop-freeze" biopsy techniques, myocardial contractility (LV dp/dt max, length-tension, and force-velocity relationships) and metabolism (adenine nucleotides, creatine phosphate, and glycogen) were studied in 46 intact dogs supported by normothermic cardiopulmonary bypass and subjected to either 60 minutes of continuous ischemic arrest or to four 15-minute intervals of ischemia each followed by 5 minutes of reperfusion. Following ischemia the hearts were reperfused for 30 minutes and defibrillated after the first 10 minutes. There were no significant differences in either metabolic parameters or contractile function between the groups. Although partial regeneration of adenosine triphosphate and glycogen occurred during reperfusion, only creatine phosphate achieved normal values and the end result was no difference between the two techniques. These data indicate that 5 minutes of coronary reperfusion between consecutive episodes of ischemic arrest affords no greater intraoperative protection of the myocardium than does continuous aortic cross-clamping.
