Superior action of magnesium-lidocaine-1-aspartate cardioplegia to glucose-insulin-potassium cardioplegia in experimental myocardial protection

del Nido cardioplegia in adult cardiac surgery - scopes and concerns

The convenience offered by a single-dose cardioplegia strategy is the avoidance of interruption of the flow of surgery and, more importantly, a significant reduction in the cross-clamp time. del Nido cardioplegia is an extracellular cardioplegic solution which serves these purposes and has been used successfully in pediatric cardiac surgery. The subsequent extrapolation of its use in adult cardiac surgery has returned encouraging results, as evidenced by recent literature. The use of del Nido cardioplegia in adults has been reported to shorten the cross-clamp time, cardiopulmonary bypass time and overall operating time. Intraoperative peak glucose value and insulin requirement have also been reported to be lower with del Nido cardioplegia, which can have prognostic significance. There have been reports of lesser incidence of atrial fibrillation and the number of defibrillations required with use of this technique. However, some unique concerns still remain. The lack of prospective randomized trials, the trend of elevation in CKMB (as reported by one study) and the need for a protocol-based approach to its use in adults are to be given due consideration while adopting its use in adults. This review attempts to have an overview on del Nido cardioplegia, its advantages, the recent studies comparing it with conventional cardioplegia techniques and the potential areas of concern with its use in adult cardiac surgery.

Surgical treatment of cardiac involvement in Takayasu arteritis

Cardiac involvement is a serious disorder in Takayasu arteritis. Surgical treatment of aortic root and coronary artery lesions due to Takayasu arteritis has many potential difficulties due to its inflammatory nature. We operated on 15 patients with cardiac involvement stemming from Takayasu arteritis. These patients are classified into 3 groups depending on the clinical diagnosis and surgical procedures employed: coronary artery involvement alone--coronary artery bypass grafting (CABG), three patients (group A), aortic regurgitation with intact coronary artery--Aortic valve replacement or modified Bentall's operation, eight patients (group B), and aortic regurgitation with coronary artery involvement g aortic valve replacement or modified Bentall's operation with CABG, (4 patients) (group C). CABG was performed using saphenous vein graft. For aortic valve replacement or replacement of both the aortic valve and ascending aorta, a prosthetic valve or composite graft with Teflon felt flange was fabricated during surgery and treated with fibrin glue before insertion. A double fixation method with reinforcement by a Teflon felt strip was employed for proximal anastomosis of the flanged prosthesis. A button-shaped coronary ostium was directly anastomosed to the composite graft. There was no operative or hospital mortality. One patient died of brain abscess at 6 months after surgery and another patient with CABG required a second operation due to graft failure. Steroid therapy is recommended in cases diagnosed as being in an active stage until the inflammatory signs disappear.

The significant role of membrane stabilization in hypothermic cardioplegic cardiac preservation in a canine experimental model

Isolated mongrel hearts were preserved for 6 h at 5 degrees C followed by normothermic reperfusion for 2 h. The dogs were divided into three groups; K+-cardioplegic solution alone, group C, n = 7; K+-cardioplegic solution with lidocaine 200 mg/l, group L, n = 7; and K+-cardioplegic solution with betamethasone 250 mg/l and lidocaine 200 mg/l, group B + L, n = 7. Ventricular fibrillation occurred early during reperfusion in all dogs in group C, in one of seven in group L, and in two of seven dogs in group B + L. The serum MB fraction of creatinine kinase (MB-CK), mitochondrial aspartate aminotransferase (m-AAT) and calcium overload were suppressed to a greater extent in both groups L and B + L during reperfusion compared to group C. Myocardial ATP, total adenine nucleotide, and creatine phosphate did not differ between the three groups at the end of reperfusion. Myocardial ADP and AMP declined significantly during reperfusion in group C, however, they remained unchanged in group B + L and increased in group L which showed significantly higher levels compared to group C. Left ventricular functional recovery during reperfusion was consistently better in both group L and B + L compared to group C. These results suggested that membrane stabilization prevents myocardial damage from hypothermia and cardioplegia and provides better myocardial viability and functional recovery in donor heart preservation.

Effect of aprotinin to improve myocardial viability in myocardial preservation followed by reperfusion

Isolated canine hearts were preserved at 4 degrees C with multi-dose cardioplegic solution every hour for 6 hours. Reperfusion was observed for 2 hours under cross-circulation without cardiotonic drugs. The aprotinin group (n = 8), which received cardioplegic solution with added aprotinin (150 KIU/mL), was compared with the control group (n = 6). The increase in tissue adenosine triphosphate and total adenine nucleotide content during reperfusion was significant in the aprotinin group; there was no change in the control group, and the levels at the end of reperfusion tended to be higher in the aprotinin group than in the control group. Tissue adenosine diphosphate levels remained unchanged in both groups. Tissue adenosine monophosphate levels declined during reperfusion in both groups and were slightly lower in the control group. Tissue levels of cyclic adenosine monophosphate remained unchanged in the aprotinin group whereas they increased during ischemia and declined significantly during reperfusion in the control group. Tissue levels of cyclic guanosine monophosphate declined during reperfusion in both groups without difference. Creatine phosphate levels recovered in both groups without difference. Serum cyclic guanosine monophosphate concentration tended to be lower in the aprotinin group than in the control group. Serum creatine kinase-MB level increased slightly during reperfusion in both groups without difference. N-acetyl-beta-D-glucosaminidase levels were significantly suppressed during reperfusion in the aprotinin group as compared with the control group. These results suggest that aprotinin is effective in preserving adenine nucleotide and adenosine triphosphate levels and in stabilizing tissue cyclic adenosine monophosphate levels in prolonged hypothermic cardioplegic preservation followed by reperfusion.

Metabolic effect of glucose, insulin and potassium cardioplegia

Glucose-insulin-potassium (GIK) solution is widely used as a cardioplegic infusate for myocardial protection during aortic cross-clamping, to obtain rapid diastolic arrest and preservation of energy stores. Nine male patients with aorto-coronary bypass grafting procedure were studied with regard to the metabolic influence of GIK cardioplegia. Hyperglycemia was induced by the infusion of GIK solution for one week after surgery. The serum level of non-esterified fatty acid was high for one week while the triglyceride level was maintained at a high level only in the early post-operative period. Insulin, glucagon and growth hormone which influence carbohydrate and lipid metabolism were also elevated for one week after infusion of GIK solution. We conclude that the derangement of carbohydrate and lipid metabolism which is provoked by the use of GIK cardioplegia normalizes within two weeks after operation.