Reduction of systolic and diastolic dysfunction by retrograde coronary sinus perfusion during off-pump coronary surgery.
OBJECTIVE
We evaluated the protective effects of retrograde coronary sinus perfusion to offset potential systolic and diastolic dysfunction (myocardial stunning) after temporary regional ischemia needed for off-pump coronary artery bypass grafting.


METHODS
Twenty Yorkshire-Duroc pigs (31.8 +/- 3.9 kg) underwent 15 minutes of mid-left anterior descending coronary artery ischemia in the beating heart. In 8 pigs, no protective measures were used. In 12 pigs, an aorta-coronary sinus shunt (with conventional cannulas) allowed retrograde perfusion during temporary ischemia; in 6 of these pigs, no leakage to the right atrium was ensured. Regional endocardial contraction was measured with sonomicrometer crystals. Systolic dysfunction (impaired regional shortening), diastolic dysfunction (contraction extending into early diastole), and coronary sinus nitric oxide and endothelin-1 levels were recorded.


RESULTS
Before ischemia, contraction did not extend into the diastolic interval. During ischemia, paradoxic bulging occurred in all hearts except in the occlusive coronary sinus shunt group (16% +/- 6% of baseline, P <.01). Sixty minutes after ischemia, systolic segment shortening recovered 36% +/- 24% without retrograde perfusion versus 56% +/- 20% and 61% +/- 14% with coronary sinus shunting (P <.05). Diastolic dysfunction (as percentage of diastolic time in contraction) was 38% +/- 16% in the nontreated group versus 22% +/- 22% and 9% +/- 9% (P <.05) after shunting and occlusive shunting, respectively. This correlated with a left ventricular end-diastolic pressure increase of 4 mm Hg in the ischemic group versus no change in the retrograde perfusion groups. Nitric oxide decreased 15% without shunting and increased 8% after occlusive coronary sinus shunting (P <.05).


CONCLUSIONS
Retrograde coronary sinus perfusion during simulated off-pump coronary revascularization diminishes systolic and diastolic dysfunction. An aortic-coronary sinus shunt is a rapid, recognized approach that can improve myocardial muscle and endothelial safety during off-pump coronary artery bypass grafting.
Castellá
Manuel
M
Department of Surgery, University of California, Los Angeles School of Medicine, 90095, USA.
Buckberg
Gerald D
GD
D000818:Animals; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000378:metabolism / Q000503:physiopathology* / Q000601:surgery*; D003326:Coronary Circulation / Q000502:physiology; D003402:Creatine Kinase / Q000378:metabolism; D052279:Creatine Kinase, MB Form; D004195:Disease Models, Animal; D019332:Endothelin-1 / Q000378:metabolism; D005260:Female; D015918:Infusion Pumps, Implantable; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology*; D015425:Myocardial Reperfusion; D009569:Nitric Oxide / Q000378:metabolism; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*; D013318:Stroke Volume / Q000502:physiology; D013552:Swine; D014693:Ventricular Fibrillation / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology
D015415:Biomarkers; D019332:Endothelin-1; D007527:Isoenzymes; D009569:Nitric Oxide; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form