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Abstract
A controlled study was undertaken to evaluate the relationship between myocardial
oxygen consumption (MO2) and epicardial S-T segment improvement in an ischemic heart preparation during left
ventricular (LV) bypass. Twelve mongrel dogs were prepared with left ventricular-aortic
bypass, coronary sinus cannulation, and a multiple point epicardial electrocardiographic
technique. The left anterior descending coronary artery was ligated low (Group I)
or high (Group 77) after baseline studies. After ischemic baseline studies, increasing
degrees of LV bypass were performed at a constant mean aortic ;Vessure and heart rate.
The final infarct size was determined by the nitroblue tetrazolium staining technique.
Group 1—a significant reduction in the average (![Math Eq]()
) segment elevation occurred during 50 to 59 percent of LV bypass during which MO2 was reduced 10.9 percent from controls. A maximum ![Math Eq]()
reduction of 75 percent occurred during LV decompression during which MO2 was reduced 52.8 percent from controls. The final infarct size for Group I was 9.8
± 0.9 Gm. per 100 Gm. of LV. Group II—a significant reduction in ![Math Eq]()
segment elevation occurred only after 90 to 99 percent LV bypass was achieved during
which MO2 was reduced 28.1 percent from controls. LV decompression produced a maximum ![Math Eq]()
reduction of 63 percent during which MO2 was reduced 50.2 percent from controls. The final infarct size for Group II was 21.1
± 0.4 Gm. per 100 Gm. of LV. This study indicates that larger degrees of bypass are
required to decrease the ischemic areas encountered in larger infarctions. LV decompression
is most beneficial in reducing ischemic myocardium surrounding large infarctions.
) segment elevation occurred during 50 to 59 percent of LV bypass during which MO2 was reduced 10.9 percent from controls. A maximum 
reduction of 75 percent occurred during LV decompression during which MO2 was reduced 52.8 percent from controls. The final infarct size for Group I was 9.8
± 0.9 Gm. per 100 Gm. of LV. Group II—a significant reduction in 
segment elevation occurred only after 90 to 99 percent LV bypass was achieved during
which MO2 was reduced 28.1 percent from controls. LV decompression produced a maximum 
reduction of 63 percent during which MO2 was reduced 50.2 percent from controls. The final infarct size for Group II was 21.1
± 0.4 Gm. per 100 Gm. of LV. This study indicates that larger degrees of bypass are
required to decrease the ischemic areas encountered in larger infarctions. LV decompression
is most beneficial in reducing ischemic myocardium surrounding large infarctions.To read this article in full you will need to make a payment
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References
- Effects of a selective bypass of the left ventricle.Circulation. 1963; 27: 835
- Modification of infarct size.Circulation. 1971; 43: 317
- Reduction in myocardial ischemia by left ventricular bypass after acute coronary artery occlusion.J. Thorac. Cardiovasc. Surg. 1974; 67: 829
- Reduction of the oxygen utilization of the heart by left heart bypass.Circ. Res. 1962; 10: 298
- Synergistic effects of Phenylephrine and counterpulsation in canine cardiogenic shock.Am. J. Physiol. 1973; 224: 1044
- Left heart bypass and myocardial oxygen uptake.in: Öogan F. Mechanical assistance of the circulation. Georg Thieme Verlag, Stuttgart1967: 96-102
- Comparison of intra-aortic balloon pumping and left ventricular decompression on myocardial ischemic injury after experimental coronary artery occlusion.Surg. Forum. 1971; 22: 149
- Reduction of experimental myocardial infarct size by corticosteroid administration.J. Clin. Invest. 1973; 52: 599
- Factors influencing infarct size following experimental coronary artery occlusion.Circulation. 1971; 43: 64
- Effects of intra-aortic balloon counter pulsation on the severity of myocardial ischemic injury following acute coronary occlusion.Circulation. 1972; 45: 1150
- Reduction by hyaluronidase of myocardial necrosis following coronary artery occlusions.Circulation. 1972; 46: 430
- Effect of glucose-insulin-potassium infusion on myocardial infarction following experimental coronary artery occlusion.Circulation. 1972; 45: 1160
- Microscopic identification of early myocardial infarct by alterations in dehydrogenase activity.Am. J. Pathol. 1963; 42: 379
- Myocardial changes associated with cardiogenic shock.N. Engl. J. Med. 1971; 235: 133
- Myocardial oxygen utilization during left heart bypass.Arch. Surg. 1974; 109: 635
- Hemodynamic and metabolic studies during two types of left ventricular bypass.Surg. Forum. 1972; 23: 176
- Modification of myocardial infarct volume: An experimental study in the dog.Arch. Surg. 1973; 107: 682
- Coronary artery occlusion in the conscious dog: Effects of alterations in heart rate and arterial pressure on the degree of myocardial ischemia.Circulation. 1972; 46: 323
- Effects of partial and of total heart-lung bypass on the heart.J. Appl. Physiol. 1959; 14: 458
- Coronary insufficiency, relations between hemodynamic, electrical and biochemical parameters.Circ. Res. 1966; 18: 178
- A simple technique for the production of chronic complete heart block in dogs.J. Appl. Physiol. 1968; 25: 631
Article info
Publication history
Accepted:
October 27,
1975
Footnotes
☆Supported in part by Public Health Service Research Grant 5-RO 1-HL 13426 and by the Jane B. Barsumian Trust Fund.
Identification
Copyright
© 1976 Published by Elsevier Inc.
