Cardiopulmonary bypass (CPB) standard heparin and protamine therapy is a relatively satisfactory part of conventional CPB practice. However, some problems are known to result from both heparin and protamine sulphate administration. These include: allergic reaction and thrombocytopenia due to heparin, and anaphylactoid reactions, negative inotropic effects, pulmonary oedema and pulmonary hypertension due to protamine administration. Low molecular weight heparin (LMWH) should theoretically be superior decreasing the adverse effects of standard heparin. In addition, it should not require the use of protamine for heparin neutralization. These potential benefits of LMWH encourage the experimental evaluation of the use of LMWH during open-heart surgery before preliminary clinical applications.

In an attempt to assess their respective values for purposes of drug monitoring, plasma, red blood cell, atrial, and ventricular concentrations of amiodarone and N-desethylamiodarone (NDA) were measured, in 50 surgical patients, after a single oral dose (30 mg/kg); hemodynamic changes were assessed also. Amiodarone concentration was lower in red blood cells than in plasma and in myocardium. A relationship was found between the red blood cell concentration and plasma or myocardial concentrations of amiodarone (r = 0.79 and r = 0.68, p < 0.00001). Hemodynamic studies were available in 17 treated patients and 13 control subjects before and at the time of surgery. In control subjects, hemodynamics did not change with time and general anesthesia. Oral amiodarone decreased the cardiac index (p < 0.05) and heart rate (p < 0.001) index. The increase in capillary wedge pressure was related to amiodarone or NDA plasma, myocardial, and red blood cell concentrations (for amiodarone: r = 0.61, p = 0.006; r = 0.69, p < 0.001; and r = 0.53, p = 0.02, respectively). We concluded that oral amiodarone impairs hemodynamics and that measurement of the amiodarone plasma concentration rather than the red blood cell concentration is the easiest method of monitoring the drug. However, establishment of the clinical utility of drug monitoring during chronic administration of amiodarone needs further investigation.

The effects of the oxygen-carrier fluorocarbons on myocardial infarct size were assessed in non-exchange-transfused dogs subjected either to a 3-hour occlusion of the left anterior descending coronary artery (LAD) followed by 2 hours of reperfusion (protocol I) or to a 5-hour permanent LAD occlusion (protocol II). Fluorocarbon administration was begun 30 minutes after LAD occlusion and was continued over the entire period of ischemia. After 5 hours, the hearts were excised and areas of necrosis were visualized by triphenyl tetrazolium chloride staining while risk regions were assessed by radiolabeled microspheres injected after coronary occlusion just before the onset of therapy, and further, in protocol I, by thallium-201 perfusion imaging performed at the end of fluorocarbon administration.

Une étude du complément hémolytique total et des fractions C3, C4 et C3 pro-activateur (facteur B) a été effectuée chez 10 malades subissant un pontage aorto-coronarien sous circulation extra-corporelle. Il existe chez tous les malades une diminution significative du taux sanguin du CH50, C 3 et facteur B dès la cinquième minute de la circulation extra-corporelle, pérsistant durant toute l'intervention. Par ailleurs, nous avons constaté une neutropénie initiale et un effet de Shunt intrapulmonaire significatif 24 heures après l'intervention. Nous suggérons que l'activation du complément, essentiellement par la voie alterne, pourrait contribuer à créer une leucoagglutination dans les capillaires pulmonaires à l'origine d'un œdème pulmonaire de type lésionnel.

The complement system (CH50, C3, C4, C3 PA) was monitored during extra-corporeal circulation in 10 patients with ischemic-heart disease. Mean concentrations of CH50, C3, C4, and C3 PA significantly decreased as early as 5 minutes after initiation of the extra-corporeal circulation and decrement remain steady all over the surgical procedure. Transient neutropenia occurred early during the procedure. A significant hypoxemia was present only 24 hours after surgery. We suggest that a complement mediated leukostasis might occur with sequestration in the lungs and contribute to endothelial cell damage with pulmonary edema known as the "post-pump syndrome".

Pre-operative radionuclide angiography, a non-invasive technique for evaluating ventricular function, was performed on 34 consecutive patients undergoing aortobifemoral bypass grafting for abdominal aortic occlusive disease, to determine whether pre-existing coronary artery disease causes significant modification of cardiac function. Patients were divided into two groups according to medical history. Group I had 23 patients with no symptoms of coronary artery disease and Group II had 11 patients, six with previous myocardial infarction and five with angina pectoris. There was a significant difference in left ventricular ejection fraction and in cardiac output between these two groups. A flow-directed pulmonary artery catheter was inserted in eight patients in Group II who had an ejection fraction less than 50% and a nitroglycerin infusion was used in six cases to maintain pulmonary capillary wedge pressure below 20 mmHg. In the other patients, only central venous pressure was monitored. All patients had uneventful operative courses. It is concluded that left ventricular function is significantly altered in patients with symptoms of both abdominal aortic occlusive disease and coronary artery disease. By contrast, cardiac function is normal in patients free from symptoms of coronary artery disease, and central venous pressure monitoring seems sufficient in the management of these patients during aortobifemoral bypass grafting.

This investigation assesses whether the size of an acutely revascularized myocardial infarct (MI) could be reduced by altering the composition of the initial reperfusate. Nineteen open-chest dogs underwent 4-hour occlusion of the left anterior descending coronary artery and were then assigned to a treatment group: 12 dogs to selective intracoronary infusion of the modified reperfusate over 30 minutes before resumption of blood flow for 60 minutes and 7 to a control group (90 minutes of unmodified blood reperfusion). The modified reperfusate consisted of 500 ml of a fluorocarbon-oxygenated crystalloid solution (PO2 650 mm Hg; total O2 content 5.5 vol%) whose composition was adjusted by decreasing Ca++ (0.25 mM), increasing pH (7.60) and adding glucose (1.8 g/liter). Four hours after occlusion, technetium-99m-labeled microspheres were injected into the left atrium. After 90 minutes of reperfusion, the heart was removed and sliced transversely. Areas riot perfused by microspheres (areas at risk) were traced, planimetered and compared with the areas of necrosis after incubation in triphenyltetrazolium chloride. Areas were then converted into weights. In control dogs, the weight of necrotic myocardium was not significantly different from the weight at risk (5.0 ± 0.7 vs 7.0 ± 0.8 g, respectively [mean ± standard error of the mean]), whereas it was markedly reduced in treated dogs (5.9 ± 0.5 vs 9.4 ± 0.7 g, respectively, p < 0.001). The weight of salvaged myocardium was 3.4 ± 0.5 g in treated dogs vs 1.9 ± 0.4 g in the control group (p < 0.02). When the dogs were classified according to the amount of left ventricle at risk, the protective effects of the modified reperfusate were apparent mainly in the largest areas at risk (> 40% of the left ventricle). We conclude that a modified initial reperfusate can significantly reduce MI size, possibly by preventing some reperfusion-related damage in the reversibly injured myocardial areas, and fluorocarbons are effective in oxygenating such crystalloid reperfusion solutions that might enhance the beneficial effects of intracoronary fibrinolysis.

A case of coronary artery spasm during a non-cardiac surgical procedure is presented. Two paroxysmal episodes of ST segment elevation in lead 11 and aVF without changes in V5 developed during general anaesthesia. These changes were not preceded by increases in heart rate or arterial pressure. The second episode was associated with a ventricular bigeminal rhythm. This case demonstrates the importance of monitoring several leads in patients likely to develop peroperative spasm of the coronary arteries. Intravenous nitroglycerin was effective in treating the second episode of coronary artery spasm. However, this episode occurred in spite of nitroglycerin administered intravenously at a rate of 0.25 microgram/kg min.

Thrombose revelee par deux accidents emboliques cerebraux. Le remplacement valvulaire mitrale a ete entrepris en urgence sur les donnees de l'echocardiogramme et du radiocinema

During aortic valve surgery, cardioplegic solution is delivered through direct cannulation of both coronary ostia. Since this approach may cause an intimal injury leading to acute dissection or late ostial stenosis, we have evaluated retrograde coronary sinus perfusion (RCSP) as a means of delivering cardioplegia in 12 patients undergoing aortic valve replacement. The retroperfusion of the cardioplegic solution was performed with a balloon-tipped catheter inserted into the coronary sinus through the right atrium. The perfusion pressure averaged 40 mm Hg. Twelve patients undergoing antegrade coronary perfusion served as controls. Both groups were matched for preoperative and intraoperative data. The postoperative evaluation focused on hemodynamic status, as evidenced by serial measurements of right-sided pressures and cardiac output at 1, 6, 12, 18, and 24 hours after operation. The stroke volume index and the left ventricular and right ventricular systolic stroke work indexes were then calculated. There was no statistically significant difference between the two groups. We conclude that RCSP is a simple, safe, and effective means of cardioplegic protection during aortic valve surgery.

Aorto-left ventricular discontinuity may result from destruction of the aortic ring in aortic valve endocarditis, making solid implantation of a valvular prosthesis difficult. We believe the best technique to be the insertion of a valved Dacron tube from a noninfected area of the left ventricle to the ascending aorta distal to the coronary ostia, the coronary arteries being reimplanted in the tube. This technique implies a relatively dilated aortic ring and the integrity of the supra-annular aortic wall. When these conditions are not fulfilled, the problem has to be solved by supra coronary implantation of an aortic prosthesis with double aorto-coronary bypass grafts. Valved tubes from the left ventricular apex to the abdominal aorta is complex major surgery, the indications for which should be limited to the most mutilating forms of endocarditis causing such severe annular and periannular lesions that the two preceding techniques are impossible. Despite the advances in surgical technique, operative mortality remains high, a problem that could undoubtedly be reduced by early surgery before the association of hemodynamic and infectious complications lead to severe cardiac failure and widespread local lesions.