The Journal of thoracic and cardiovascular surgery
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J. Thorac. Cardiovasc. Surg. · Mar 1992
Intermediate-term survival and functional results after arterial repair for transposition of the great arteries.
An assessment of late morbidity and mortality is essential before arterial repair can be considered truly corrective for patients with transposition of the great arteries. We describe the early and intermediate-term results in 126 patients who underwent arterial repair. Operation was performed at a median age of 6 days, with 76 patients operated on within the first 7 days of life. ⋯ All patients are in sinus rhythm, and none requires antiarrhythmic medications. These data suggest that pulmonary artery reconstruction with a single pantaloon patch may be associated with a decreased requirement for reoperation. Intermediate-term survival and functional results are excellent after arterial repair for transposition of the great arteries.
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J. Thorac. Cardiovasc. Surg. · Mar 1992
The effect of temperature on cerebral metabolism and blood flow in adults during cardiopulmonary bypass.
The effect of temperature on cerebral blood flow and metabolism was studied in 41 adult patients scheduled for operations requiring cardiopulmonary bypass. Plasma levels of midazolam and fentanyl were kept constant by a pharmacokinetic model-driven infusion system. Cerebral blood flow was measured by xenon 133 clearance (initial slope index) methods. ⋯ The temperature coefficient was then computed as the ratio of cerebral metabolic rate of oxygen consumption at 37 degrees C to that at 27 degrees C. The median temperature coefficient for man on nonpulsatile cardiopulmonary bypass is 2.8. Thus reducing the temperature from 37 degrees to 27 degrees C reduces cerebral metabolic rate of oxygen consumption by 64%.
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J. Thorac. Cardiovasc. Surg. · Mar 1992
Mechanical enhancement and myocardial oxygen saving by synchronized dynamic left ventricular compression.
Dynamic cardiomyoplasty with synchronously paced skeletal muscle grafts has recently been developed to augment the performance of impaired myocardium. This method has been reported effective to improve patients' general status and some hemodynamic parameters. It is unknown, however, how a systolic dynamic cardiac compression, as in dynamic cardiomyoplasty, affects left ventricular energetics. ⋯ When end-systolic pressure was matched with the pre-dynamic cardiac compression control level by decreasing end-diastolic volume at a constant stroke volume so that external mechanical work under dynamic cardiac compression returned to the control level, both pressure-volume area and myocardial oxygen consumption significantly decreased. In contrast to a marked increase in myocardial oxygen consumption for a given increase in external mechanical work by either volume loading or dobutamine, dynamic cardiac compression did not increase myocardial oxygen consumption for the same increase in external mechanical work. Thus dynamic cardiac compression augments left ventricular pump function without increasing myocardial oxygen demand or compromising coronary blood flow.
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J. Thorac. Cardiovasc. Surg. · Mar 1992
Effect of sodium aspartate on the recovery of the rat heart from long-term hypothermic storage.
We have investigated the reported ability of aspartate to enhance greatly the cardioprotective properties of the St. Thomas' Hospital cardioplegic solution after prolonged hypothermic storage. Rat hearts (n = 8 per group) were excised and subjected to immediate arrest with St. ⋯ In still further studies, hearts (n = 8 per group) were perfused in the working mode at either high (greater than 80 ml/min) or low (less than 50 ml/min) left atrial filling rates. Under these conditions, if functional recovery was expressed as a percentage of preischemic function, artifactually high recoveries could be obtained in the low-filling-rate group. In conclusion, assessment of the protective properties of organic additives to cardioplegic solutions requires careful consideration of (1) the consequences of coincident changes in ionic composition and (2) the characteristics of the model used for assessment.
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J. Thorac. Cardiovasc. Surg. · Feb 1992
Randomized Controlled Trial Clinical TrialCerebrovascular and cerebral metabolic effects of alterations in perfusion flow rate during hypothermic cardiopulmonary bypass in man.
Recent experimental and clinical investigations provide conflicting evidence regarding the effects of changes in the systemic flow rate from the pump oxygenator on cerebral blood flow and the cerebral metabolic rate of oxygen consumption. However, the results of existing clinical studies are difficult to interpret because of the confounding effects of differences in management of arterial carbon dioxide tension and use of anesthetic and vasoactive agents during cardiopulmonary bypass. To clarify the relationship among perfusion flow rate, cerebral blood flow, and cerebral metabolic rate of oxygen consumption in man during hypothermic cardiopulmonary bypass, we varied perfusion flow rate in random order to either 1.75 or 2.25 L.min-1.m-2 and studied cerebral blood flow (measured by clearance of xenon 133) and cerebral metabolic rate of oxygen consumption (estimated as the product of cerebral blood flow and the cerebral arteriovenous oxygen content difference) in patients managed with both the alpha-stat (group 1) and the pH-stat (group 2) methods of pH and arterial carbon dioxide tension adjustment. ⋯ In each patient other variables known to exert effects on cerebral blood flow and cerebral metabolic rate of oxygen consumption, including temperature, arterial carbon dioxide tension, arterial oxygen tension, mean arterial pressure, and hematocrit, were maintained constant between measurements. In both groups, mean arterial pressure at both pump flow rates was similar because of spontaneous reciprocal alterations in systemic vascular resistance, that is, as perfusion flow rate declined, systemic vascular resistance increased; as perfusion flow rate increased, systemic vascular resistance declined. Under these tightly controlled conditions, pump flow variation per se exerted no effect on cerebral blood flow or cerebral metabolic rate of oxygen consumption in either group.