Latissimus dorsi cardiomyoplasty. Perioperative management and postoperative evolution.

Twelve men aged 45 to 69 years, NYHA class 3 or 4 with low isotopic ejection fraction (18 +/- 7 percent), underwent cardiomyoplasty. Eight required cardiopulmonary bypass to treat an associated cardiac lesion. Preoperatively, all patients needed inotropic support with dobutamine and half of them vasodilators, increasing cardiac index by nearly 100 percent. The SvO2 remained over 67 percent during the different stages of the surgical procedure. The mean operating time was 438 +/- 75 min. None of the patients required intra-aortic balloon counterpulsation. Inotropic and vasodilator support was continued in the ICU and appeared especially important during weaning from mechanical ventilation. The average stay in ICU was 6.8 +/- 4.0 days. Three patients died of cardiac failure respectively 8, 11 and 15 months after CMP. One patient underwent transplantation. The eight other surviving patients showed clinical improvement from the third month, but objective criteria for hemodynamic improvement were noted only after one year. Cardiomyoplasty can be an alternative treatment for selected cases of cardiomyopathy.

Immunization by bovine thrombin used with fibrin glue during cardiovascular operations. Development of thrombin and factor V inhibitors.

Brief case histories of three patients aged 58, 38, and 44 years are reported. All underwent cardiovascular operations. Subsequently hemostasis test abnormalities developed between the seventh and eighth postoperative days after exposure to bovine thrombin used with fibrin glue. These were characterized by an increased activated partial thromboplastin time (64 to 147 seconds), prothrombin time (19 to 24 seconds), bovine thrombin time (> 120 seconds) and a markedly reduced factor V level (< 10% in two patients and 16% in the third patient). A patient plasma dilution of 1 in 200 with a normal plasma pool was necessary to correct bovine thrombin time. No fast-acting or progressive inhibitor against factor V could be detected by coagulation tests, and fresh frozen plasma perfusion had no effect. Plasmapheresis was performed preventatively to avoid bleeding, and factor V levels stabilized at around 50% after two to four exchanges. Immunologic studies showed that the inhibitors were directed not only against bovine factors but also against human ones. Therefore factor V decrease could have been the result of rapid clearance from the circulation of complexes formed with a nonneutralizing inhibitor that is not detected by clotting tests. These antibodies were purified by standard methods and immunoaffinity. Fast immunization could be explained by a prior sensitization to bovine thrombin exposure during previous operations. It is suggested that bovine thrombin used with fibrin glue contains small amounts of factor V and may be responsible for these abnormalities. This is in agreement with previous literature reports. However, these described neutralizing factor V inhibitors, which were easily detected.

Clinical use of ganciclovir during renal failure and continuous hemodialysis.

OBJECTIVE: Data is scarce concerning ganciclovir, used in CMV-related diseases in transplant patient with renal failure, especially when dialysis is necessary. DESIGN: Prospective trial. SETTING: Intensive care unit in a university hospital, and pharmacy laboratory. PATIENTS: pharmacokinetics were obtained in 3 patients undergoing continuous veno-venous hemodialysis (CVVHD) (PAN 69). INTERVENTIONS: HPLC measurements of plasmatic and ultrafiltrated ganciclovir were determined at 17 times intervals after a 5 mg/kg every 48 h dosage. RESULTS: Peak and trough concentrations were respectively 16.1 +/- 2.4 and 5.5 +/- 0.5 mg/l, sieving coefficient 0.75-0.95, and volume of distribution at steady state 0.64 +/- 0.09 l/kg, half life (beta phase) 18.6 +/- 1.8 h. No direct toxicity, or CMV-related death occurred. CONCLUSION: Plasma concentrations were higher than the ID 90. A dosage of 5 mg/kg/48 h of ganciclovir could be used during CVVHD, and ideally adjusted to monitoring of plasma drug levels.

Evolution of right ventricular performance after CABG.

34 patients scheduled for coronary artery bypass graft (CABG) surgery were studied during postoperative period. Right ventricular performance was specially performed with use of cardiac output computer REF-1 Edwards Lab., before Anaesthesia (T1) and at 6 investigation times after surgery during and after mechanical ventilation. The sixth first postoperative hours were marked by a decrease of cardiac index (2.56 +/- 0.4 to 2.41 +/- 0.41.mn-1.m2) and right Ventricular Ejection Fraction (RVEF) (0.48 +/- 0.07 to 0.37 +/- 0.09). The second period was the weaning period with a further drop of RVEF (0.43 +/- 0.1 to 0.36 +/- 0.07) without change in cardiac index (2.80 +/- 0.51.mn-1.m2, suggesting a ventricular post-operative and weaning depression, as previously described for the left ventricle. In addition, postoperative tachycardia (Heart rate = 59 +/- 9 at T1 to 95 +/- 14 at T7) may contribute to myocardial ischemia.

Glucose and insulin supply before cardiopulmonary bypass in cardiac surgery: a double-blind study.

A double-blind study versus placebo was carried out to evaluate the effects of a 500-mL infusion of 30% glucose containing 300 units of ordinary insulin and 5 g of potassium chloride administered at a rate of 1.66 mL.kg-1.h-1 for 1 hour before cardiopulmonary bypass. The hemodynamic parameters measured before and after administration of the solution, after cardiopulmonary bypass, after administration of protamine, and 3 hours after leaving the operating room showed the beneficial effect of the glucose-insulin-potassium infusion on cardiac index (+23.6% after protamine infusion) and left (+16.3% 3 hours postoperatively) and right (+47.3% after cardiopulmonary bypass) ventricular workload index with a decrease in systemic vascular resistance. For patients with a cardiac index of less than 2.5 L.min-1.m-2 before administration of the glucose-insulin-potassium solution, the beneficial effect on the cardiac index was further increased 3 hours postoperatively (+33%). During the postoperative period, the requirements in inotropic drugs and disturbances of rhythm were not significantly different between the two groups, although they were twofold lower in patients receiving glucose-insulin-potassium. Laboratory tests showed that postoperative hypoglycemia was more common in the glucose-insulin-potassium group but had no detrimental effects; it no longer occurs since we began administering the glucose infusion at 15 g/h over 8 hours. The data reflect the beneficial effect associated with the action of glucose-insulin-potassium on myocardial protection during heart operations and were confirmed by the hemodynamic results. This argues in favor of the routine use of this technique, especially in patients with poor ventricular function.

[Current role of intra-aortic diastolic balloon counterpulsation in heart surgery]. / Place actuelle de la contrepulsion diastolique par ballonnet intra-aortique en chirurgie cardiaque.

Intra-aortic balloon counterpulsation (IABP) is a relatively non-invasive method of circulating assistance, easy to use and which has benefitted from a number of technological improvements in recent years. This retrospective study over 4 years was undertaken to analyse the results of IABP and to determine its role in therapeutic arsenal against cardiac failure. Sixty five patients, 57 coronary and 8 valvular cases, with an average age of 61 +/- 10 years were included. The indications of IABP were: a bridge to transplantation (3 cases), complications of coronary angioplasty (4 cases), and low cardiac output after cardiopulmonary bypass (58 cases), where IABP was curative in 85% of cases and prophylactic in 15% of cases (patients with risk factors of low output state after CPB). Beforehand, 65% of patients had poor left ventricular function (LVEF < 40% and/or CI < 2.2 l/mn/m2). An Aries Medical M700 console was used. The percutaneous femoral approach was feasible in 87% of cases. The results were: improvement with discharge from intensive care unit in 60% of cases, transient improvement in 7% of cases, no improvement in 15% of cases and cardiac transplantation in 8% of cases. The outcome was worse when the preoperative LV function was poor and when high dose inotropic agents had to be used. Survival was 100% in those patients in whom IABP was a prophylactic measure. The average duration of IABP was 72 hours, survival being significantly lower in those in whom IABP was continued for over 3 days. The complications (12.7%) were thromboembolic.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparison of the hemodynamic effects of dobutamine and enoximone in the treatment of low cardiac output after valvular surgery]. / Comparaison des effets hémodynamiques de la dobutamine et de l'énoximone dans le traitement du bas débit cardiaque après chirurgie valvulaire.

Forty patients developed low cardiac output states after surgery for mitral valve disease or with associated cardiac disease and were randomly allocated to two treatment groups, one group to receive Dobutamine (D) and the other Enoximone (E), a phosphodiesterase inhibitor. Haemodynamic assessment covered a 24 hour period but treatment was continued for as long as was necessary. An improvement was observed from the 15th minute of treatment. At the second hour, the cardiac index had increased by 55% in Group E and by 59% in Group D whilst the heart rate increased by only 12% in Group E compared to 30% in Group D. The right and left heart filling pressures decreased by 25 to 27% in the 2 groups. The systemic arterial resistances fell by 36 to 37% without any significant changes in systemic or pulmonary arterial pressures. No significant difference was demonstrated in the haemodynamic responses to Dobutamine and Enoximone in this study. The duration of treatment was significantly shorter in Group E than in Group D (59 +/- 22 hrs vs 86 +/- 49 hrs) as was the patient's stay in the intensive care unit (92 +/- 37 hrs vs 155 +/- 129 hrs). The duration of assisted ventilation was the same in the two groups. These results suggest that Enoximone is as effective as Dobutamine in the treatment of low cardiac output after mitral valve surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

[Arrhythmia in patients with low cardiac output after valvular surgery. Randomized, double-blind comparative study of dobutamine versus enoximone]. / Arythmies chez les patients en bas débit cardiaque après chirurgie valvulaire. Etude randomisée, aveugle et comparative dobutamine versus énoximone.

Forty patients with low cardiac output (cardiac index less than 2.2 l/mn/m2 and pulmonary wedge pressure greater than 15 mmHg) after valvular surgery were randomised into two groups. Patients in Group 1 were given 5 to 10 micrograms/Kg/mn of Dobutamine (D) and those In Group 2 a bolus of Enoximone (E) 1 mg/kg followed by an intravenous infusion of 5 to 10 micrograms/Kg/mn. Holter ECG monitoring over 42.65 +/- 6.02 hrs (24-48 hours) was obtained and interpreted blindly in 37/40 patients (19 Group D and 18 Group E). The results were analysed by the t and X2 tests. A p value of less than .05 was considered statistically significant. The two groups were comparable. No deaths occurred during the protocol period. The total duration of inotropic therapy (86 +/- 49 hours) and the period spent in the intensive care unit (155 +/- 129 hours) were longer in Group D than in Group E (60 +/- 23 hrs and 92 +/- 37 hrs, respectively; p less than .05). Antiarrhythmic therapy was used more often in Group D (4 patients) than in group E (1 patient) (p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

[Indications for inotropic agents in cardiac surgery]. / Indications des agents inotropes en chirurgie cardiaque.

Inotropic drugs are widely used before, during and after cardiac surgery. Besides the old well known inotropic drugs, new sympathomimetic drugs and phosphodiesterase inhibitors are available. They can be used alone or in combination. The choice of drug is difficult to make and depends, for one part, on the side-effects of each drug. Before surgery, they are required for patients who present with cardiogenic shock while waiting for emergency repair of their lesion. During surgery, inotropic drugs are used before, during and after using cardiopulmonary bypass. After surgery, they are used to treat low cardiac output states. A decision algorithm is suggested, but it is modified by personal clinical experience, aetiological patterns and pharmacological data. Therapeutic doses must be adjusted according to haemodynamic data. Physiological controls are required, such as venous return and heart rate. Mechanical assistance devices must not be forgotten, especially after myocardial reperfusion and weaning from extracorporeal circulation.

[Hemodynamic effects of amrinone in low cardiac output after mitral valve replacement]. / Effets hémodynamiques de l'amrinone dans le bas débit cardiaque après remplacement valvulaire mitral.

The efficacy of amrinone was assessed in the treatment of low cardiac output states occurring within 24 h after mitral valve replacement in an open prospective trial. It included 7 women and 5 men, aged 58 +/- 10 years. Four patients had also had simultaneous aortic valve replacement. Patients entered in the study if their cardiac index (CI) remained less than 2.2 l.min-1.m-2 after pulmonary wedged pressure (Ppw) had been increased to at least 15 mmHg, the patient having a temperature greater than 36 degrees C. Amrinone was given so as to increase Cl by at least 30% and to decrease Ppw by at least 30%. Patients were given a mean of 1.5 mg.kg-1 amrinone during the first hour, followed by a constant rate infusion of 9 +/- 3 micrograms.kg-1.min-1 over at least 24 h. The usual haemodynamic parameters were measured and calculated before giving amrinone, and after 1, 3, 6, 24, and 48 h. After 1 h of treatment, systolic arterial pressure, cardiac index, systolic index and left ventricular stroke work increased by 22, 42, 23, and 47% respectively, whilst Ppw decreased by 27% (p less than 0.01). Heart rate rose and systemic vascular resistance decreased but not significantly. Right atrial pressure, right ventricular stroke work, pulmonary artery pressure and pulmonary vascular resistance did not change. These effects were all maintained throughout the 48 h infusion. Amrinone had to be replaced by another agent (a beta-agonist) in 3 cases because of arrhythmia, lack of efficacy or thrombocytopaenia. In this setting, amrinone increased left ventricular performance with little effect on the right ventricle.

[Inhaled nitric oxide in anesthesia and intensive care]. / Monoxyde d'azote inhalé en anesthésie-réanimation.

The role of endothelium in vascular relaxation is linked to the existence of endothelium derived relaxing factors (EDRF) known since 1980. In 1987, nitric oxide (NO) was identified as one of these factors. NO acts in many physiologic and pathophysiologic events. Atmospheric NO is a pollutant. Inhaled NO allows selective pulmonary vasodilation and is used to treat pulmonary artery hypertension (PAH). As inhaled NO is inactivated immediately in the blood by linking to haemoglobin, systemic vasodilation does not occur and right ventricular coronary perfusion pressure does not decrease. This is particularly important in the treatment of right ventricular failure due to PAH following cardiothoracic surgery. In patients with an acute respiratory distress syndrome (ARDS), inhaled NO improves the perfusion of adequately ventilated pulmonary territories. Very low concentrations of NO, such as two parts per million, decrease intrapulmonary venous admixture and may reverse hypoxaemia. However its long term benefits in ARDS must be assessed more accurately with multicentre controlled studies. Inhaled NO also improves refractory hypoxaemia in neonates. Its bronchodilatory effect, demonstrated experimentally, does not occur in acute obstructive bronchopulmonatory disease. The toxicity of NO, and overall of its oxidated derivative NO2 requires precise conditions of administration and close monitoring of inhaled fractions. In that case, the risk of NO toxicity seems very low when compared to its therapeutic benefits in selected patients.

[Vascular effects of nicergoline]. / Effets vasculaires de la nicergoline.

The vascular effects of nicergoline, a post-synaptic alpha receptor antagonist, were studied using a total haemodilution non pulsatile normothermic cardiopulmonary bypass with a bubble oxygenator during cardiac surgery. Anaesthesia was induced with fentanyl 30 micrograms.kg-1 and diazepam 0.25 mg.kg-1 and maintained with incremental doses of fentanyl. All the patients were intubated using pancuronium bromide (0.1 mg.kg-1) and artificially ventilated (FIO2 = 1). Nine patients randomly selected received 10 ml of saline (group 1) and 11 other 5 mg nicergoline (group 2) into the venous line of the extracorporeal circuit. Pump flow remained constant during 10 min. Arteriolar resistance was assessed by mean arterial pressure recording and venous capacitance by the level of venous reservoir. Statistical analysis was carried out using analysis of variance and the Newman-Keuls test. In group 1, arteriolar resistance increased by 17.0 +/- 21.8% at 10 min (not significant), whereas in group 2 it decreased by 22.8 +/- 8.1% at 2 min (p less than 0.05) and then increased slowly. It then remained 18% lower than in group 1 at 10 min. In group 1, venous capacitance decreased regularly by 1 ml.kg-1.min-1 during 10 min (-10.0 +/- 6.2 ml.kg-1 at 10 min), whereas in group 2 it decreased up to the 6th min (-4.2 +/- 3.3 ml.kg-1) and then remained stable, with a 5.4 ml.kg-1 difference with group 1 at 10 min (p less than 0.05). Therefore, nicergoline seemed to cause venoconstriction during cardiopulmonary bypass, possibly through a baroreflex mechanism.

[Vascular effects of ketamine during anesthesia with diazepam and fentanyl]. / Effets vasculaires de la kétamine en présence d'une anesthésie par diazépam et fentanyl.

Twenty-six adults undergoing elective cardiac surgery were anaesthetized with diazepam and fentanyl (induction with 200 micrograms.kg-1 and 30 micrograms.kg-1 respectively, maintenance with incremental doses). Normothermic constant perfusion output cardiopulmonary bypass was carried out with a membrane oxygenator, haemodilution with Ringer's lactate solution, and cardioplegia with St. Thomas's Hospital solution. The patients were randomly assigned to two groups. They were given either 2 mg.kg-1 of ketamine (group 1) or placebo (5 ml of normal saline) (group 2) via the venous line of the oxygenator. The non pulsatile flow was then kept at a steady rate of 2.41 x min-1.m-2, and no other infusion or treatment was started during the study period (ten minutes). The mean arterial pressure and blood reservoir level were measured every min during this period. The systemic vascular resistances did not change significantly in either group, but remained 27% lower in the ketamine group than in the placebo group (p less than 0.01). The blood reservoir level was 37% higher in the ketamine group (p less than 0.01), suggesting a decreased venous capacitance. It is therefore concluded that ketamine leads to venous constriction, and probably arterial dilation, during fentanyl-diazepam anaesthesia and normothermic cardiopulmonary bypass. The venous effects of ketamine could explain why it is usually well tolerated in hypovolaemic states.

[Right ventricular assistance using a centrifugal pump after heart transplantation]. / Assistance ventriculaire droite par pompe centrifuge après transplantation cardiaque.

A case of right ventricular assistance required after emergency heart transplantation is reported. The patient was a 62 year-old man with terminal congestive heart failure due to ischaemic cardiomyopathy. Preoperatively, this patient had a cardiac index of 1.93 1.min-1.m-2, moderate pulmonary hypertension (mean Ppa: 34 mmHg) and pulmonary arteriolar resistances at 440 dyn.s.cm-5; clinical examination revealed pulmonary oedema, cardiac liver and oliguria with renal failure. Cardio-pulmonary bypass lasted 145 min, including 50 min of assistance after graft reperfusion. Despite postoperative dopamine and dobutamine treatment, oliguria and central venous pressure increased, and higher doses of catecholamines (adrenaline, noradrenaline) and pulmonary intraarterial prostaglandin E1 infusions were required. Despite these agents and haemofiltration, mechanical assistance was needed and a centrifugal pump set up. Diuresis and haemodynamic parameters improved. The patient was weaned from this assistance after 102 h. A satisfactory haemodynamic status was then maintained, but still required 1.4 micrograms.kg-1.min-1 noradrenaline and 0.02 microgram.kg-1.min-1 prostaglandin E1. Six days later, the patient was weaned from the ventilator, but he rapidly developed fatal aspergillus septicaemia. This case demonstrates that temporary mechanical assistance can be useful for treating right ventricular failure occurring after transplantation.

[Whole body and thoracic impedance changes induced by cardiopulmonary bypass]. / Modifications de l'impédance corporelle totale et thoracique induites par la circulation extracorporelle.

Impedance is defined as resistance to alternating electrical current. It is inversely proportional to the volume of tissues traversed by the current. Cardiopulmonary bypass, as used in cardiac surgery, results in extravascular fluid overload manifested by a decrease in whole body and thoracic impedance. This non-invasive method has been used in 18 adult patients before, and in the days immediately following cardiopulmonary bypass for non-mitral cardiac surgery. Right and left thoracic impedances were reduced by 32 and 37 percent respectively during the first postoperative hour and returned to preoperative values after the second postoperative day. Whole body impedance was reduced by 14 percent in the first post-operative day, and this was accompanied by 17 percent and 16 percent decreases in the PaO2/PAO2 and PaO2/FIO2 ratios respectively. There was no correlation between impedance and these ratios which reflect pulmonary gases exchanges. Impedance appears to be a simple method to evaluate whole body and thoracic water contents, thereby providing guidance in post-cardiac surgery management.

[Antibiotic prophylaxis in heart surgery]. / Antibioprophylaxie en chirurgie cardiaque.

Cardiac surgery enters mainly into the class I of Altemeier ("clean surgery"). However, many factors may explain an intraoperative contamination: surgery of long duration, extra-corporeal circulation, aspiration of blood and air, immunodepression...). In fact, the infectious risk decreases from about 25% with placebo to 5% with prophylactic antibiotics. The staphylococcal infections are the most frequent (mediastinitis, endocarditis, parietal infections...). Cephalosporins, particularly of second-generation type (cefamandole, cefuroxime), perform better than antistaphylococcal penicillins. The combination with an amino-side may be used when Gram negative bacilli infection prevalence is high. Vancomycin is efficient but hypotension and renal impairment have been reported. Therefore, vancomycin is used in patients allergic to cephalosporins, when a high prevalence of methicillin-resistant Staphylococcus or enterococci infections is reported, or when the patient has recently received broad-spectrum antimicrobial therapy. The antibiotic doses must take into account the haemodilution due to extracorporeal circulation and the necessity to obtain sufficient serum concentrations throughout surgery. A prophylaxis of more than 48 hours is not associated with an improved outcome. In cardiac transplantation a prophylaxis is essential, but is still questioned during the insertion of pace-markers. In any case, the antibiotic prophylaxis must take into account the bacterial prevalence of each institution.

[Peroperative ultrafiltration in complete repair of ventricular septal defect in infants]. / Ultrafiltration peropératoire lors de la correction complète de communication interventriculaire du nourrisson.

Ventricular septal defect in infants induces peroperative fluid overload (particularly extravascular lung water overload) which causes some morbidity after surgical closure of the defect. Thirty infants undergoing the conventional complete correction procedure were retrospectively compared with 32 infants operated upon using ultrafiltration at the end of the cardiopulmonary bypass. There was no difference between the two groups in biological data, haemodynamic parameters and either morbidity or mortality. Nevertheless, a clinical impression of smooth follow-up in patients with ultrafiltration encourages to carry out a prospective and randomized study.

[Vascular effects of urapidil administrated during extracorporeal circulation]. / Effets vasculaires de l'urapidil administré en cours de circulation extracorporelle.

Urapidil exerts a combined central sympathetic and peripheral alpha-1 adrenergic receptor inhibition. Urapidil induces arterial vasodilation but its effects on venous capacitance are more difficult to assess. During cardiopulmonary bypass with constant perfusion index (2.4 l.min-1 x m-2) total peripheral resistance varies similarly as to arterial pressure and, as the apparatus venous reservoir is filled continuously by simple gravity from the right atrium, a decrease in venous blood reservoir level reflects an increased venous capacitance. Twenty-six patients undergoing cardiac surgery were anaesthetized with fentanyl and midazolam and randomly assigned to one of two groups. During normothermic cardiopulmonary bypass, group 1 was administered i.v. urapidil 12.5 mg and group 2 a placebo. In group 1, arterial pressure decreased by 33 +/- 14% (mean +/- SD) at the second minute while total peripheral resistance decreased from 1,384 +/- 255 to 927 +/- 193 dyn.s.cm-5. Then this two parameters regained group 2 values after the eighth minute. Reservoir blood level was lower in group 1 than in group 2 from the second to the eight minute (p < 0.05) with maximum effect at 7 minutes. It is concluded that urapidil exerts arterial and venous dilation. Its arterial effects seem greater during normothermic cardiopulmonary bypass than in normal conditions and its maximum venous effects seem to occur after its maximum arterial effects. The short duration of action may be due to the small dose administered.

[CK-MB isoenzyme in the diagnosis of myocardial infarction after myocardial revascularization surgery]. / Isoenzyme CK-MB dans le diagnostic d'infarctus myocardique après chirurgie de revascularisation myocardique.

The usefulness of measuring serum MB creatine kinase activity (CK-MB) for the diagnosis of per- and postoperative myocardial infarction (MI) was assessed in 104 patients undergoing coronary artery bypass grafts. In each patient, 15 samples were taken during the week which followed the surgical procedure. New Q waves were considered to be a criteria of MI. 19 patients developed new Q waves (MI group), whereas 57 had no significant ECG changes (control group); 13 showed only ST changes, whilst 15 had unassessable recordings. In the MI group, CK-MB was greater than in the control group, both at the first peak (8 to 10 h after induction of anaesthesia) and at the greater peak (13 to 21 h after induction) (p less than 0.05). Significant differences were also seen between both groups between 8 and 32 h after induction, but there was also a large overlap. An area under the curve (AUC) greater than 50,000 IU.l-1.min-1 had a positive predictive value of 0.64, and an AUC less than 50,000 IU.l-1.min-1 a negative predictive value of 0.89 if all the groups of patients were taken into account. An AUC greater than 65,000 IU.l-1.min-1 was always seen in MI patients, but only 25% of MI patients had a value greater than this threshold. There were no significant differences between the patient groups in the first peak time, nor in the CK-MB/total CK ratio. CK-MB appeared therefore as a less reliable criterium of per- and postoperative MI during coronary artery bypass operations than previously reported, especially when intermediate values are found.

[Plasma concentrations of diltiazem and its metabolites in coronary surgery: relation with preoperative treatment]. / Concentrations plasmatiques du diltiazem et de ses métabolites en chirugie coronarienne: relation avec le traitement préopératoire.

Preoperative oral administration of calcium channel blocking agents has been found ineffective to prevent perioperative myocardial ischaemia. Our hypothesis was that low plasma concentrations may account for this inefficiency. Twenty-three male patients, scheduled for surgical myocardial revascularisation, were administered their usual anti-anginal treatment, including 180 to 360 mg of diltiazem since more than one week. The usual dosage was given at 8.00 p.m. on the day before surgery. On the morning of surgery, after withdrawal of a first blood sample, 60 mg of diltiazem were administered per month before the induction of anaesthesia. The anaesthesia was obtained with fentanyl, midazolam or flunitrazepam, pancuronium and isoflurane as required. The cardiopulmonary bypass (CPB) was associated with total haemodilution with Ringer's Lactate and a membrane oxygenator. A second blood sample was withdrawn after CPB. Plasma concentrations of diltiazem and its two active metabolites, N-monodemethyldiltiazem (MA) and desacetyldiltiazem (M1), were assessed by HPLC. Plasma diltiazem concentrations decreased from 78 +/- 66 (mean +/- SD) to 51 +/- 42 micrograms.l-1 (p < 0.05) with wide individual variations. These concentrations were under therapeutic levels in 18 out of 23 patients before (p < 0.05) with wide individual variations. These concentrations were under therapeutic levels in 18 out of 23 patients before induction and in 22 patients after CPB. The metabolite/diltiazem ratios remained constant. A dosage-plasma concentration relationship was observed preoperatively with diltiazem and MA. It is concluded that plasma concentrations of diltiazem should be optimized preoperatively in order to prevent myocardial ischaemia.