Postoperative arrhythmias and myocardial electrolytes in patients undergoing coronary artery bypass grafting

Electrolyte changes in right atrial and skeletal muscle pre- intra- and postoperatively, and their relationship to the development of postoperative atrial fibrillation or flutter were evaluated in 31 patients with coronary artery bypass grafting (CABG). Such postoperative arrhythmias occurred in 14 patients (45%). Before CABG the skeletal muscle potassium concentration was lower in these patients than in the others: median 261.4 (range 148.2-329.5) vs 298.6 (167.1-416.4) mumol/g dry weight, p = 0.017. The right atrial potassium concentration was normal, but sodium levels were higher in the patients with, than in those without postoperative arrhythmias: median 340.3 (263.7-454.9) vs 296.3 (203.9-355.0) mumol/g dry weight, p = 0.008, indicating disturbed transmembrane electrolyte transfer. During CABG the potassium levels fell and sodium increased in both right atrium and skeletal muscle, and on postoperative day 2 the potassium content in skeletal muscle was not yet restored. Magnesium levels showed no changes in right atrium or skeletal muscle, but serum magnesium declined postoperatively. As the observed electrolyte derangements may be important in the development of postoperative arrhythmias, concomitant potassium and magnesium supplement postoperatively may be beneficial in restoring cellular potassium concentration.     

Emergent coronary artery bypass grafting in patients with acute coronary syndrome

The incidence of emergent CABG in patients with acute coronary syndrome has been decreasing, because thrombolytic therapy and/or catheter intervention have proved to be done faster and more efficient. The present indication of CABG is mostly limited to patients with left main trunk lesion or severe triple vessel disease, whose PTCA is failed with persistent chest pain or unstable hemodynamic condition. The factors associated with an increased hospital mortality are ejection fraction < 30%, age > 70 years, presence of cardiogenic shock, and cardiac index < 1.5. The interval between operation and AMI is not a significant risk factor. The prognosis of the operative survivors is relatively good. The use of the internal thoracic artery graft does not influence on the early outcome as far as the preoperative hemodynamic condition is stable. To get better surgical results, improvements in intraoperative myocardial protection and in postoperative cardiac support are imperative.     

Diagnosis of perioperative myocardial infarction by cardiac troponin T following coronary artery bypass grafting

The determinations of cardiac troponin T provide the highest diagnostic efficiency for the detection of myocardial cell necrosis. To assess perioperative myocardial infarction, serum levels of cardiac troponin T were determined in 14 patients undergoing coronary artery bypass grafting (CABG). The patients were divided into two groups: group I (n = 9), those whose troponin T was less than 1.00 ng/ml on the first postoperative day; group II (n = 5), those whose troponin T was more than 1.00 ng/ml on the first postoperative day. Troponin T levels in group II patients were significantly higher than in group I from the second to the seventh postoperative day. Two patients in group II had specific changes on the electrocardiogram detecting perioperative myocardial infarction as a new Q wave and R wave reduction. These results suggest that troponin T is a valuable marker of perioperative myocardial infarction following CABG.     

Extensive endarterectomy of the left anterior descending coronary artery combined with coronary artery bypass grafting

BACKGROUND: Complete revascularization of a diffusely diseased left anterior descending (LAD) coronary artery can be accomplished by extensive endarterectomy in conjunction with coronary artery bypass grafting (CABG). The present study was designed to assess the safety of the procedure, and which techniques lead to the best short- and long-term results. METHODS: Between January 1990 and October 1994 106 patients underwent extensive open endarterectomy of the LAD coronary artery combined with CABG at our institution. This group constituted 4.9% of all patients undergoing CABG during this period. The mean age of those studied was 64.4 +/- 9.2 years and 92% were male. In 22 patients (21%) the procedure was a repeat CABG and 12% had had percutaneous transluminal coronary angioplasty prior to the operation. Ninety-one per cent of the patients were in Canadian Cardiovascular Society (CCS) angina class 3 or 4, 91% had three-vessel disease and 36% had unstable angina at the time of surgery. The mean preoperative left ventricular ejection fraction was 53.6 +/- 14.9% (range, 15-80%). The internal mammary artery (IMA) was used to bypass the LAD coronary artery in 40 patients (38%) and a saphenous vein graft (SVG) was used in 66 patients. In 25 of the IMA bypass group an additional venous patch was used (IMA+P). RESULTS: The overall mortality rate was 9.4% (10 patients), including seven immediate postoperative deaths. When the IMA was used as a conduit the mortality rate was only 5.0%. There were seven (6.6%) postoperative non-fatal myocardial infarctions. There was a low incidence of other postoperative complications, similar to that following CABG without endarterectomy performed during the same period. Multivariate analysis identified emergency operation, two-vessel endarterectomy and female sex as independent risk factors for mortality. Upon follow-up study of 94 hospital survivors (98%), at a mean of 26.5 months (range, 1-48 months), all endarterectomy patients were in CCS class 1 or 2. Seventy-eight patients (83%) had an excellent postoperative exercise tolerance and the left ventricular function was preserved. The 4-year survival rates were 88% and 96% and the cardiac event-free survival rates were 74% and 87% in the SVG and IMA groups respectively. CONCLUSIONS: Complete revascularization of the diffusely diseased LAD coronary artery can be accomplished by adjunctive open endarterectomy with a degree of operative risk (mortality 9% and incidence of non-fatal myocardial infarction 7%). The immediate and medium-term results are improved when the IMA is used as a conduit, with or without additional venous patch. Independent risk factors for mortality were two-vessel endarterectomy, female sex and emergency operation. The long-term results revealed an overall survival rate of 92% and a cardiac event-free survival rate of 79% at 4 years, as well as excellent functional results.     

Acute myocardial infarction in patients who have had coronary artery bypass surgery

BACKGROUND: Although acute myocardial infarction (AMI) and coronary artery bypass grafting (CABG) are frequently discussed, the issue of AMI in patients who have previously had CABG has not been addressed yet. METHODS: We critically reviewed data obtained from the medical literature on this subject since 1974. RESULTS: The overall incidence of AMI is about 10% during the first 3 years after CABG, though it occurs more frequently in older male patients. It seems that the infarct size is smaller and post-AMI ejection fraction is higher in patients who have had CABG than in those who have not. Although early mortality appears to be lower, on 5-year follow-up, more patients had AMI, angina, and revascularization procedures. CONCLUSIONS: The data abstracted indicate that AMI after CABG appears to be a well-delineated entity. Further studies are necessary to determine the optimal treatment for this population.     

Study on risk factors and late results of coronary artery bypass grafting for acute myocardial infarction

Study was made on the operative results, risk factors, and late results of coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) conducted at our hospital. The subjects of the present study were 70 cases of AMI who underwent CABG during a period of five years from January 1991 to December 1995. They were composed of 61 males and 9 females whose mean age was 61.9 years. LMT disease was observed in 13 cases and preoperative shock in 18 cases. The mean aortic cross-clamp time was 64 minutes with the mean extracorporeal circulation time being 134 minutes and the mean number of grafts being 2.5. The mean preoperative-postoperative peak creatine kinase was 4479 IU/L. The number of operative deaths was 14 with a mortality rate of 20%. When compared with elective cases of CABG conducted during the same period with a mortality rate of 2.7%, the operative result of AMI was poor. The mortality rate by risk factor was 40% for age of 70 years or more, 46.2% for complication of LMT disease, 52.9% for preoperative shock, 58.3% for preoperative C.I. of less than 2.0, 80% for postoperative C.I. of less than 2.0, 28.2% for conduct of postoperative circulatory support, and 42.1% for peak creatine kinase of 5000 IU/L or more. Aortic cross-clamp time and reperfusion time (interval from onset of AMI to aortic declamp) were found not to be risk factors. Late death accounted for 5 cases including one case of cardiac death due to suspected AMI. Survival rate excluding operative deaths and hospital deaths was 98% in one year and 83.9% in five years. When compared to non cardiacevent cases, the survival rate of positive cardiac event cases was significantly poor. The operative results of severe myocardial ischemia cases represented by cases of complication of LMT disease were poor and it is considered that improvement of intraoperative myocardial protection and aggressive use of postoperative circulatory support are necessary in the future. The survival cases of those who could endure surgery was comparatively satisfactory, but when cardiac event developed, prognosis was poor and thus more rigid follow-up is considered to be necessary.     

Emergency coronary artery bypass grafting after acute myocardial infarction. What influences early postoperative mortality?

Chicken gamma-enolase cDNA was cloned and its sequence and tissue-specific expression were analyzed. The cDNA, consisting of 2273 bp of nucleotides, was composed of 86 bp of the 5'-noncoding region, 1305 bp of an open reading frame encoding a protein of 434 amino acids and 882 bp of the 3'-noncoding region. The deduced amino acid sequence showed higher homology (more than 90%) to those of mammalian gamma-enolases than to those of chicken alpha- or beta-enolases. Northern blot analysis has revealed that the mRNA for gamma-enolase (2.3 kb) is expressed in the brain and, to much less but significant extents, in the pituitary and adrenal gland of the chicken.     

Enhanced lipid peroxidation in patients during coronary artery bypass grafting

Lipid peroxidation products were measured at various time intervals in 20 patients with coronary artery disease, who underwent coronary artery bypass graft (CABG) surgery. Post-operative blood lipid peroxides were found to be significantly higher (p < 0.001) than the preoperative value. Lipid peroxides raised to a peak value of 46.42 +/- 12.86 n mol/g Alb at 5 min of reperfusion when compared to the basal value and afterwards the level declined to 41.02 +/- 7.09 at 2 hrs and remained in that level even at 24 hrs of reperfusion. This increase implies an enhancement in free radical mediated oxidation of membrane lipids during bypass surgery and thus provides evidence for free radical generation during myocardial reperfusion.     

Maximal utilization of the left internal mammary artery for coronary bypass grafting

A technique is described for using the internal mammary artery to bypass the left anterior descending coronary artery and another adjacent coronary artery even when the alignment of the two vessels is not favorable for a conventional sequential graft. The distal end of the mammary artery is amputated and used to construct a Y graft to the anterior descending artery and to the secondary target vessel.     

Coronary angioplasty versus repeat coronary artery bypass grafting for patients with previous bypass surgery

OBJECTIVES: We attempted to determine the relative risks and benefits of percutaneous transluminal coronary angioplasty (PTCA) and repeat coronary artery bypass grafting (re-CABG) in patients with previous coronary bypass surgery (CABG). BACKGROUND: Due to an expanding population of patients with surgically treated coronary artery disease and the natural progression of atherosclerosis, an increasing number of patients with previous CABG require repeat revascularization procedures. Although there are randomized comparative data for CABG versus medical therapy and, more recently, versus PTCA, these studies have excluded patients with previous CABG. METHODS: We retrospectively analyzed data from 632 patients with previous CABG who required either elective re-CABG (n = 164) or PTCA (n = 468) at a single center during 1987 through 1988. The PTCA and re-CABG groups were similar with respect to gender (83% vs. 85% male), age > 70 years (21% vs. 23%), mean left ventricular ejection fraction (46% vs. 48%), presence of class III or IV angina (70% vs. 63%) and three-vessel coronary artery disease (77% vs. 74%). RESULTS: Complete revascularization was achieved in 38% of patients with PTCA and 92% of those with re-CABG (p < 0.0001). The in-hospital complication rates were significantly lower in the PTCA group: death (0.3% vs. 7.3%, p < 0.0001) and Q wave myocardial infarction (MI) (0.9% vs. 6.1%, p < 0.0001). Actuarial survival was equivalent at 1 year (PTCA 95% vs. re-CABG 91%) and 6 years (PTCA 74% vs. re-CABG 73%) of follow-up (p = 0.32). Both procedures resulted in equivalent event-free survival (freedom from dealth or Q wave MI) and relief of angina; however, the need for repeat percutaneous or surgical revascularization, or both, by 6 years was significantly higher in the PTCA group (PTCA 64% vs. re-CABG 8%, p < 0.0001). Multivariate analysis identified age > 70 years, left ventricular ejection fraction < 40%, unstable angina, number of diseased vessels and diabetes mellitus as independent correlates of mortality for the entire group. CONCLUSIONS: In this nonrandomized series of patients with previous CABG requiring revascularization, an initial stategy of either PTCA or re-CABG resulted in equivalent overall survival, event-free survival and relief of angina. PTCA offers lower procedural morbidity and mortality risks, although it is associated with less complete revascularization and a greater need for subsequent revascularization procedures.     

Effect of aspirin in coronary artery bypass grafting

OBJECTIVES: To evaluate the effect of aspirin (ASA) therapy on postoperative blood loss, transfusion requirements, reoperation for bleeding, duration of stay in the intensive care unit and in the hospital in a selected population undergoing a first coronary artery bypass grafting (CABG) surgery. DESIGN: Prospective observational study in consecutive patients during a 3-month period. SETTING: A teaching cardiothoracic center. PARTICIPANTS: Two hundred forty consecutive patients undergoing elective coronary artery bypass grafting surgery for the first time. INTERVENTIONS: Two hundred forty consecutive patients admitted for a first CABG the day before surgery were visited. patients with an abnormal routine coagulation screen or taking drugs that might have affected their coagulation mechanisms were prospectively excluded (n = 96). The date of the last dose of ASA was recorded in the 144 remaining patients, and data were acquired prospectively. MEASUREMENTS AND MAIN RESULTS: Total mediastinal blood drainage, blood products usage, reopening, and duration of intensive care unit and hospital stay were recorded. Patients were grouped by days free of ASA. There were no significant differences detected between groups. CONCLUSIONS: In patients undergoing a first CABG and with no known factors affecting their coagulation, ASA therapy did not appear to increase blood loss, reopening for bleeding, or blood products usage requirements during the hospital stay. ASA therapy did not influence the duration of stay in intensive care or in the hospital.     

Antiphospholipid antibody syndrome in a case with redo coronary artery bypass grafting under cardiopulmonary bypass

Until now 'c-series' polysialogangliosides were known to exist in human brain only during development and in some pathological conditions like Alzheimer's disease. Using thin-layer chromatography (TLC) and immunostaining with Q211 antibody (TLC-overlay technique) we have analysed 'c-series' gangliosides in four human cerebella (age 20, 47, 52 and 54 years). Four distinct ganglioside bands, most probably corresponding to GT1c, GQ1c, GP1c and GH1c were found to exist in the analysed brains, which is convincing demonstration of the existence of 'c-series' gangliosides in normal adult human brain. Immunohistochemical analysis was performed to locate polysialogangliosides in the analysed tissue. Q211 antibody was found to bind specifically to a single subpopulation of neurons in the molecular layer of adult cerebellum. According to their position and morphology these cells correspond to stellate neurons.     

Effects of prostacyclin on myocardial hemodynamics and metabolism after coronary artery bypass grafting

OBJECTIVE: To evaluate the impact on clinical behavior of a 3-day workshop designed to increase trainees' rates of smoking cessation counseling and reminders about Pap smears in routine consultations. DESIGN: Randomized control trial. SETTING: Accredited teaching practices of the Royal Australian College of General Practitioners' Training Program. SUBJECTS: Thirty-four trainees and 1,500 consecutive adult patients ages 16-65 years. METHOD: Trainees randomly allocated to the experimental group participated in a 3-day interactive workshop on disease prevention during their 13-week family medicine term. Audiotapes of consultations with adults conducted by trainees at the beginning and end of the rotation were analyzed blind to compare assessment of patients' smoking status and, for women, date of last Pap smear. A questionnaire mailed to each patient after the consultation also allowed identification of smokers and women overdue for a smear. Consultations with these patients at risk were analyzed for preventive counseling. Inter- and intrarater reliability was calculated for audiotape analysis. RESULTS: Preworkshop rates of questions about smoking were low, occurring in 22% of consultations. While trainees allocated to the experimental workshop were more likely to ask a routine question about smoking at the end of the term than those in the control group (P = 0.01), two-thirds of smokers remained undetected irrespective of trainee group and fewer than one in five were advised to stop smoking. Reminders about Pap smears did not change as a result of training and remained low in fewer than 20% of consultations. kappa values demonstrated high reliability of audiotape analysis. CONCLUSION: This direct measurement of clinical behavior revealed that low levels of preventive care provided by trainees are resistant to skills training without reinforcement in clinical practice. In view of the importance of prevention in routine consultations, we recommend continued evaluation of more intensive educational programs. Those withstanding rigorous evaluation could be considered for implementation in similar training contexts seeking to improve the frequency and quality of disease prevention in primary medical care.     

Coronary artery bypass grafting in cases with poor left ventricular function

From January 1987 through June 1992, 18 patients with poor left ventricular function (left ventricular ejection fraction [LVEF] less than 0.3) underwent elective isolated primary coronary artery bypass surgery. The mean age was 56.4 years (range, 46 to 72 years), and 15 were males and 3 were females. Mean pre-operative LVEF measured by ventriculography was 0.26 +/- 0.03 (range, 0.19 to 0.30). Sixteen patients (88.9%) had a prior myocardial infarction and 9 (50%) had a history of congestive heart failure. Complete revascularization was the goal for all patients, and the mean number of bypass grafts was 3.0 +/- 0.8 per patient. The left anterior descending coronary artery (LAD) was revascularized in all patients. There were no operative deaths. Post-operative LVEF improved significantly from 0.26 +/- 0.03 to 0.42 +/- 0.11 (p = 0.0002), and the regional left ventricular wall motion improved in the diaphragmatic and posterobasal regions (p < 0.01). The patency of the grafts was 93.9% in all, and 100% for LAD. The mean follow-up period was 77 months, and the overall actuarial survival rate was 88.9% at 10 years. During follow-up periods, two patients died of congestive heart failure (CHF), and two required three rehospitalizations because of CHF. The overall cardiac event free rate was 75.8% at 10 years. In patients with poor left ventricular function, surgical revascularization can be performed safely, but congestive heart failure sometimes occurs during follow-up periods and may be the cause of death. Therefore alternate forms of therapy such as cardiac transplantation and/or TMLR should be considered in selected patients.     

Preoperative predictors of cost in Medicare-age patients undergoing coronary artery bypass grafting

BACKGROUND: Identification of preoperative factors that contribute to the cost of coronary artery bypass grafting could aid in predicting the procedure's expense. In this study, 30 sociodemographic and clinical preoperative factors were examined with "survival analysis" techniques to determine characteristics related to total hospital cost. METHODS: Characteristics of all patients age 65 or older undergoing isolated coronary artery bypass grafting from July 1993 to April 1995 (n = 757) were recorded. Software was developed within the hospital's Transitions Systems, Inc, database to calculate the outcome variable of total cost. Nonparametric methods were used for the univariate analysis of the data, and the Cox proportional hazards model was used for the multivariable analysis, censoring 25 patients who died in the hospital. RESULTS: Median hospital cost from the day of the operation until discharge was $15,198. Median length of stay after the operation was 6 days. Multivariable analysis revealed that age, preoperative renal failure, history of cerebrovascular accident, low ejection fraction, and surgical urgency were independent predictors of total cost. CONCLUSIONS: This study, using an accurate representation of true hospital cost and a modeling technique that accounts for the confounding effect of in-hospital death on cost, provides a template for analysis of cost in other patient groups.     

Does arterial revascularization decrease the risk of infarction after coronary artery bypass grafting?

BACKGROUND: This study sought to determine whether extensive arterial grafting reduces the prevalence and consequences of infarct after coronary artery bypass grafting. METHODS: Post-primary coronary artery bypass grafting infarcts and time-related events thereafter were identified by 99.9% complete follow-up of 9,600 patients (1971 to 1992). The contribution of arterial grafting to freedom from infarct was assessed by multivariable hazard function analysis to adjust for other risk factors. RESULTS: Unadjusted 1-month and 10-year freedom from infarction was 97% and 86%. By multivariable analysis, arterial grafting lowered the prevalence of periprocedural (p = 0.005), intermediate term (p = 0.007 and 0.006), and late infarction (arterial grafting to the left anterior descending coronary artery, p = 0.0006). Unadjusted survival after first infarct after coronary artery bypass grafting was 74% and 52% at 1 and 10 years; arterial grafting improved 10-year survival from 48% to 59% (p = 0.002). An additional benefit or cost of extending arterial grafting (n = 1,727) beyond a single one could not be identified (p > 0.1). CONCLUSIONS: Arterial conduits, particularly to the left anterior descending coronary artery, should be used for coronary artery bypass grafting to reduce early and late myocardial infarction and its consequences. However, use of more than a single arterial graft appears to confer no additional benefit.     

Early results of combined carotid endarterectomy and coronary artery bypass grafting in patients with severe coronary and carotid artery disease

The management of patients with carotid artery disease who require coronary artery bypass grafting (CABG) remains controversial. Several published series from the USA (including one with prospective randomization) advocate a combined approach of carotid endarterectomy (CEA) followed immediately by coronary artery bypass surgery. However, experience of combined carotid endarterectomy and coronary bypass grafting has not been previously reported by a centre from the United Kingdom. Between 1986 and 1991 we performed this combined procedure on 18 patients who required myocardial revascularization and had co-existing severe (> 70%) carotid stenosis. Sixteen patients (89%) had angina and 11 patients (61%) had symptomatic carotid artery disease. The perioperative mortality was 5.5% and the ipsilateral perioperative stroke rate was 5.5%. These early results are encouraging and suggest that further evaluation of combined carotid endarterectomy and coronary artery bypass surgery is warranted.     

Fatal myocardial infarction in a young patient due to coronary arteritis

This paper has introduced a child management protocol which incorporates better facial seal of the relative analgesic nosepiece together with rubber dam control which effectively allows the operator to concentrate on the precise delivery of the restorative option. The benefits of immediate treatment must be weighed up against the potential psychological distress of not having benefited from the luxury of behavioural management intervention.