The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Sep 1996
Protective effects of dimethyl amiloride against postischemic myocardial dysfunction in rabbit hearts: phosphorus 31-nuclear magnetic resonance measurements of intracellular pH and cellular energy.
The effects of 5-(N,N-dimethyl)amiloride, a potent and specific Na(+)-H+ exchange inhibitor, were investigated in isolated perfused rabbit hearts subjected to ischemia and reperfusion. Phosphorus 31-nuclear magnetic resonance spectroscopy was used to monitor intracellular pH, creatine phosphate, beta-adenosine triphosphate, and inorganic phosphate. After cardioplegic arrest with St. ⋯ The creatine phosphate resynthesis and inorganic phosphate reduction during reperfusion were also unaffected. These findings suggest that Na(+)-H+ exchange plays an important role not only during reperfusion but also during ischemia for the development of postischemic cardiac dysfunction most likely by inducing primary Na+ and secondary Ca2+ overload. Specific Na(+)-H+ exchange inhibitors like dimethyl amiloride would have a potential therapeutic profile in cardiac surgery, especially if added before ischemia.
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Repair of anterior leaflet prolapse: chordal transfer is superior to chordal shortening.
Several techniques are currently used to repair anterior leaflets with elongated or ruptured chordae. To evaluate the efficacy of these techniques, we analyzed the case histories of 108 patients operated on from 1989 through 1992 with degenerative mitral valve disease and prolapse of the anterior leaflet. The mean age was 59 +/- 15 years (range 18 to 87 years) and 74 (69%) were male. ⋯ We conclude that chordal transfer is superior to chordal shortening, providing a more predictable correction of mitral regurgitation and a lower incidence of reoperation. Reoperations after chordal shortening are a result of rupture of the previously shortened chordae.
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialBiocompatibility of heparin-coated extracorporeal bypass circuits: a randomized, masked clinical trial.
Cardiopulmonary bypass circuits cause morbidity during cardiac operations. Plasma proteins and cellular components are stimulated by contact with the cardiopulmonary bypass circuit and can cause bleeding and postperfusion syndrome. This is especially true in patients undergoing reoperative cardiac procedures, which carries a higher risk of postoperative bleeding and prolonged ventilation compared with primary cardiac surgical procedures. ⋯ Both groups had similar heparin and protamine administration, blood transfusions, postoperative alveolar-arterial oxygen gradient, time to extubation, length of intensive care unit stay, and overall morbidity and mortality. Clinical outcome and blood loss did not differ between the groups. We conclude that heparin-coated cardiopulmonary bypass circuits did not improve biochemical or clinical markers of biocompatibility in a reoperative patient population.
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialLow-dose and high-dose aprotinin improve hemostasis in coronary operations.
Prophylactic aprotinin therapy has become a popular method to reduce bleeding associated with cardiac operations. Today essentially two dose regimens are used, a high-dose regimen with administration throughout the complete operative procedure and a low-dose regimen with administration only during bypass. In unblinded studies both regimens were found to be equally effective. ⋯ The observation that low-dose aprotinin significantly improved hemostasis but did not inhibit hyperfibrinolysis supports our previous finding that low-dose aprotinin mainly protects platelet adhesive function. The better result obtained with high-dose aprotinin may indicate the contribution of hyperfibrinolysis to bleeding after cardiopulmonary bypass. Because high-dose aprotinin is administered outside the period of full heparinization and might therefore increase the risk of thromboembolic complications, we propose a modification of the low-dose schedule to increase aprotinin levels sufficient for plasmin inhibition before release of the aortic crossclamp.
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J. Thorac. Cardiovasc. Surg. · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialLeukocyte depletion results in improved lung function and reduced inflammatory response after cardiac surgery.
Leukocyte depletion during cardiopulmonary bypass has been demonstrated in animal experiments to improve pulmonary function. Conflicting results have been reported, however, with clinical depletion by arterial line filter of leukocytes at the beginning of cardiopulmonary bypass. In this study, we examined whether leukocyte depletion from the residual heart-lung machine blood at the end of cardiopulmonary bypass would improve lung function and reduce the postoperative inflammatory response. ⋯ After operation, pulmonary gas exchange function (arterial oxygen tension at a fraction of inspired oxygen of 0.4) was significantly higher in the leukocyte-depletion group 1 hour after arrival to the intensive care unit (p < 0.05) and after extubation (p < 0.05). There were no statistical differences between the two groups with respect to postoperative circulating platelet levels and blood loss, and no infections were observed during the whole period of hospitalization. These results suggest that leukocyte depletion of the residual heart-lung machine blood improves postoperative lung gas exchange function and is safe for patients who are expected to have a severe inflammatory response after heart operations.