Time course of recovery from frostbitten phrenics after coronary artery bypass graft surgery

Bilateral diaphragmatic paralysis developed in a patient after coronary artery bypass graft surgery during which cold cardioplegia was used. The patient's progress and eventual recovery over an 18-month period is described, with particular reference to chest wall motion and respiratory pressure measurements.     

Prognostic significance of nonsustained ventricular tachycardia identified postoperatively after coronary artery bypass surgery in patients with left ventricular dysfunction

INTRODUCTION: Nonsustained ventricular tachycardia (NSVT) occurs frequently in the postoperative period (< or = 30 days) after coronary artery bypass graft (CABG) surgery, a setting where many factors may play a role in its genesis. The prognosis of NSVT in this setting in patients with left ventricular (LV) dysfunction is unknown. This study was designed to assess its significance. METHODS AND RESULTS: We compared the outcome of untreated patients enrolled in the Multicenter Unsustained Tachycardia Trial with coronary artery disease (CAD), LV dysfunction, and NSVT identified postoperatively after CABG (n = 228; mean age 67 years, 84% males) versus nonpostoperative settings (n = 1,302; mean age 66 years, 85% males). Sustained monomorphic ventricular tachycardia was induced in 27% and 33% (P = 0.046) of patients with postoperative and nonpostoperative NSVT, respectively. The 2- and 5-year rates of arrhythmic events were 6% and 16%, respectively, in postoperative patients versus 15% and 29% in nonpostoperative patients (unadjusted P = 0.0020, adjusted P = 0.0082). The 2- and 5-year overall mortality rates were 15% and 36%, respectively, for postoperative patients versus 24% and 47% for nonpostoperative patients (unadjusted P = 0.0005, adjusted P = 0.027). Patients whose NSVT was identified early (<10 days) versus late (10-30 days) after CABG had significantly lower 2- (13% vs 23%) and 5-year (30% vs 52%) mortality rates (unadjusted P = 0.024, adjusted P = 0.018). CONCLUSION: In this population of patients with CAD and LV dysfunction, the occurrence of postoperative NSVT, especially within 10 days after CABG, portends a far better outcome than when it occurs in nonpostoperative settings. This suggests that in a such setting, NSVT represents a less specific risk factor for future events and should be considered when assigning risk and treatment of similar patients.     

Cardiovascular time course after digoxin administration in left ventricular dysfunction after coronary artery bypass grafting

Intravenous digoxin, 1 mg, was administered over 8 hours to 10 cardiac patients with left ventricular (LV) dysfunction after coronary artery bypass grafting. The cardiovascular effects of digoxin were monitored over 20 hours by indwelling pulmonary artery and radial artery lines and were compared with those of a control group of 10 patients who had normal postoperative LV function. Digoxin administration produced an increased cardiac index and mean arterial blood pressure within 2 hours. Within 4 hours after digoxin administration pulmonary artery wedge pressure in patients receiving digoxin was significantly lower than in control patients. At 16 hours there was a significant increase in both the LV stroke work and LV stroke work index in patients receiving digoxin vs control patients. Two patients receiving digoxin and 3 control patients had changes in cardiac rhythm during the study. Thus, digoxin can be safely administered to postoperative patients with LV dysfunction and is an acceptable inotropic agent.     

Coronary artery bypass surgery in patients with severe left ventricular dysfunction

Objective: The role of coronary artery bypass grafting (CABG) in patients with severe left ventricular dysfunction was evaluated. Methods: Two hundred and twelve patients (152 men, 60 women; age 35 to 82, mean 55) with ejection fraction (EF) of less than 30% underwent CABG between January 1996 and February 2001 by a single surgeon (SA). They compromised of 12% of 1759 patients operated on in this period. EF ranged from 17% to 30% (mean 25%). Preoperatively 68% had congestive heart failure and 72% had severe angina (CCS 3 or 4). A left main lesion was found in 26% of the cases. The mean number of grafts was 3.18 per patient. The left internal mammary artery (LIMA) was used on 107 patients (50.4%). Preoperative intraaortic balloon pump (IABP) was used on 32 patients (15%). Endarterectomy was performed on 53 patients (25%). The patients were followed for up to 58 months (mean 28.7). Results: Twelve patients died in hospital (5.6%). Survival was 94%, 87%, 80% and 73% at 1, 2, 3 and 4 years respectively. Among the preoperative variables survival was negatively affected by chronic renal failure, older age, congestive heart failure, elevated pulmonary artery pressure and recent myocardial infarction, by means of multivariate analysis. Preoperative IABP support improved the operative mortality significantly (P=0.002). Use of LIMA did not have any influence on survival. Conclusion: CABG on patients with poor left ventricular function: (1) Can be performed with an acceptable mortality. (2) Mid term results are encouraging. (3) Preoperative IABP support improves the chance of survival.     

Gender differences in recovery after coronary artery bypass graft surgery

This study examined the effect of gender on symptom evaluation, symptom response, and physical functioning following coronary artery bypass graft surgery. Symptom evaluation and symptom response were measured at baseline and 2, 4, and 6 weeks and 3 months following surgery, and physical functioning was measured at baseline, 6 weeks, and 3 months. The sample included 46 men and 19 women randomly assigned to the routine care group of a larger study examining symptom management intervention influence on recovery outcomes in elderly coronary artery bypass graft patients. No significant differences were found in symptom evaluation, symptom response, or physical functioning by gender over time. Women reported consistently higher symptom evaluation scores for shortness of breath, fatigue, depression, sleep disturbance, swelling, and anxiety and lower mean physical and vitality subscale scores than men at every time point. Gender-specific symptom management strategies should be developed and tested to address the differences in the reporting of symptoms by men and women.     

Preservation of left ventricular function during coronary artery bypass graft surgery

Effects of hypothermic potassium cardioplegia on left ventricular performance and myocardial damage were assessed in 35 patients undergoing coronary artery bypass surgery. Hemodynamic data and enzymatic evidence of left ventricular ischemic damage were examined and compared in the immediate postoperative period. Left ventricular stroke work index showed a significant depression during the first hour with gradual recovery and a significant increase after 24 h. Myocardial specific isoenzyme creatine kinase (CK-MB) showed a very good nonlinear relationship with stroke work index within the whole range, whereas lactate dehydrogenase isoenzyme (LDH-I) had no relationship with the stroke work index. There was a high incidence of transient postoperative arrhythmias and electrical activity took a long time to stabilize. Left ventricular ultrastructure was generally well preserved. The results of this study demonstrate adequate structural and functional preservation of left ventricle by hypothermic potassium cardioplegia.     

Can patients with severe left ventricular dysfunction be treated by coronary artery bypass surgery?]

Forty three men and 3 women, with an average age of 59 years (13 to 78 years) underwent aorto-coronary bypass surgery despite severe left ventricular dysfunction (ejection fraction < 35%); 96% of the patients had previous infarction; 60% (N = 28) had unstable angina, 52% (N = 24) had had pulmonary oedema or an episode of congestive cardiac failure. The average ejection fraction was 29 +/- 4%, range 17 to 35%. Thirteen patients had ventricular aneurysms, 4 had grade 3 or 4 mitral regurgitation. The coronary lesions were usually multivessel left main coronary (6), triple vessel disease (27), double vessel disease (12), single vessel disease (1). The average number of bypass grafts per patient was 2.3. The average aorting clamping time was 63 minutes (range 26 to 133 minutes). There were 4 mitral valve replacements, 4 resections of ventricular aneurysms and 1 double procedure (aneurysmectomy and valve replacement). The operative mortality was 2.1% (1 death). During an average follow-up period of 27 months (range 3 to 90 months), there were: 2 recurrent infarctions, 13 episodes of cardiac failure and 8 cardiac deaths (cardiac failure: 5, sudden death: 2, recurrent infarction: 1). Two patients underwent cardiac transplantation. The regression of angina (90% of operated patients were asymptomatic) and the low operative risk, justify aortocoronary bypass surgery despite left ventricular dysfunction in patients with severe symptoms (unstable angina, chronic, invalidating angina). The medium-term results indicate a high risk of cardiac failure which is partially responsible for the secondary mortality rate of 17% at 2 years.     

Usefulness of the ejection fraction response to dobutamine infusion in predicting functional recovery after coronary artery bypass grafting in patients with left ventricular dysfunction

Quantification of dysfunctional but viable myocardium has high prognostic value for improvement of left ventricular (LV) function after coronary artery bypass grafting (CABG). Dobutamine stress echocardiography (DSE) can assess viable myocardium by segmental wall motion changes during stress. However, analysis of wall motion is subjective with only moderate interinstitutional agreement (70%) and frequently overestimates functional improvement after CABG. In contrast, calculation of ejection fraction (EF) is less subjective and allows a more precise quantification of global contractile reserve. The aim of the study was to compare the prognostic value of EF response and segmental wall motion changes during DSE for the prediction of LV functional recovery after CABG. Forty patients underwent DSE before CABG. EF responses were assessed at rest, low-dose dobutamine, and at peak stress using the biplane disk method. Wall motion was scored using a 16-segment 5-point model. Resting radionuclide ventriculography (RNV-LVEF), performed before and 8 ± 2 months after CABG, was used as an independent reference. Five patients were excluded because of perioperative infarction or poor echo images. In 11 of 35 patients, RNV-LVEF recovered >5%. Improvement in EF during dobutamine infusion predicted RNV-LVEF recovery after CABG significantly better than segmental wall motion changes (72% vs 53%, p = 0.03). A biphasic EF response (i.e., improvement in ≥10% at low dose and subsequent worsening at peak stress) had the highest predictive value (80%) for late functional recovery. In conclusion, EF response to dobutamine infusion was superior to segmental wall motion changes in predicting RNV-LVEF recovery after CABG.     

Structural and functional changes of the myocardium after coronary artery bypass surgery in patients with postinfarction left ventricular remodeling

In patients with left ventricular end diastolic dimensions >5--< or =5.5 cm myocardial revascularization was associated with significant decreases of diastolic and systolic left ventricular dimensions in immediate postoperative period. This adaptational phenomenon was called passive reducing left ventricular remodeling. In patients with left ventricular end diastolic dimensions <5 and >5.5 cm revascularization was associated with dilation of the left ventricle. Restoration of myocardial blood supply produced overall positive effect on left ventricular functional capacity in patients with various severity of its postinfarction remodeling. Pathways of realization of this positive effect could be different.     

冠心病伴重度心功能不全患者非体外循环冠状动脉旁路移植术22例临床分析

目的:分析心功能不全冠心病患者行非体外循环冠状动脉搭桥(OPCABG)的临床资料,总结围术期规律,提出治疗方法。方法:回顾性分析2008年1月至2012年6月,同一术式手术的22例射血分数(EF)<30%的冠心病患者行OPCABG的资料(组1)。同时随机选择同数目的 EF在30%～40%(组2),>40%(组3)的患者的资料作对比。结果:所有患者均痊愈出院。组1与组3比较,在院术前调整天数,室壁瘤手术例数,IABP使用例数及时间,ICU停留时间,使用强心药种类,术后住院天数和住院费用,差异均有统计学意义(P<0.05)。组2、组3术后住院天数,住院费用差异无统计学意义(P>0.05)。结论:心功能不全患者行OPCABG风险大,手术费用高,所占医疗资源多,应慎重选择病例。此类患者通过合理方式的再血管化,积极的围术期处理,亦可得到良好的治疗效果。     

Off-pump coronary artery bypass grafting in left ventricular dysfunction

Between August 2004 and May 2006, 124 patients undergoing coronary artery bypass grafting with ejection fractions 相似文献   

Usefulness of the ejection fraction response to dobutamine infusion in predicting functional recovery after coronary artery bypass grafting in patients with left ventricular dysfunction

Quantification of dysfunctional but viable myocardium has high prognostic value for improvement of left ventricular (LV) function after coronary artery bypass grafting (CABG). Dobutamine stress echocardiography (DSE) can assess viable myocardium by segmental wall motion changes during stress. However, analysis of wall motion is subjective with only moderate interinstitutional agreement (70%) and frequently overestimates functional improvement after CABG. In contrast, calculation of ejection fraction (EF) is less subjective and allows a more precise quantification of global contractile reserve. The aim of the study was to compare the prognostic value of EF response and segmental wall motion changes during DSE for the prediction of LV functional recovery after CABG. Forty patients underwent DSE before CABG. EF responses were assessed at rest, low-dose dobutamine, and at peak stress using the biplane disk method. Wall motion was scored using a 16-segment 5-point model. Resting radionuclide ventriculography (RNV-LVEF), performed before and 8 ± 2 months after CABG, was used as an independent reference. Five patients were excluded because of perioperative infarction or poor echo images. In 11 of 35 patients, RNV-LVEF recovered >5%. Improvement in EF during dobutamine infusion predicted RNV-LVEF recovery after CABG significantly better than segmental wall motion changes (72% vs 53%, p = 0.03). A biphasic EF response (i.e., improvement in ≥10% at low dose and subsequent worsening at peak stress) had the highest predictive value (80%) for late functional recovery. In conclusion, EF response to dobutamine infusion was superior to segmental wall motion changes in predicting RNV-LVEF recovery after CABG.     

Independence of left ventricular pressure-volume ratio from preload in man early after coronary artery bypass graft surgery

The response of the maximum value of the left ventricular pressure-volume ratio to preload augmentation by blood or plasma expanders was studied in 11 patients during the first 24 hr after coronary artery bypass graft surgery. Increasing the mean left atrial pressure from 10 to 15 and 20 mm Hg resulted in no change in the maximum pressure-volume ratio in the group as a whole. In certain individual patients, however, the maximum pressure-volume ratio changed with volume infusion, and these changes were accompanied by simultaneous changes in afterload. The observed changes in pressure-volume ratio were in the same direction as the changes in afterload (systolic pressure), suggesting a dependence of maximum pressure-volume ratio on afterload. These results show that the maximum pressure-volume ratio is independent of preload in the first 24 hr after coronary artery bypass graft surgery with the pericardium open; thus the maximum pressure-volume ratio is a useful index of postoperative left ventricular function when afterload is unchanged. However, because this ratio (a single-point assessment of the pressure-volume relationship) may not be a good estimate of Emax, we recommend a more complete determination of the locus of the "upper left corners" of the pressure-volume loops for measurement of Emax to provide a more accurate indicator of the myocardial contractile state.     

Prognosis of patients with frequent premature ventricular complexes and nonsustained ventricular tachycardia after coronary artery bypass graft surgery

Background: Previous studies in small groups of predominantly nongeriatic patients showed that complè ventricular arrhythmias occurring after coronary artery graft (CABG) surgery are of no prognostic significance. The purpose of this study was to compare the prognosis of patients with and without advanced grade ventricular arrhythmias (AGVA) after CABG in a large group of patients. [In this paper, AGVA is used as an abridged definition of frequent premature ventricular complexes (PVCs) and nonsustained ventricular tachycardia (NSVT) which represent advanced grade ventricular arrhythmias.] Methods: Twenty-four hour ambulatory electrocardiographic (ECG) monitoring was performed 3 days after CABG in 185 consecutive patients with and 185 closely matched control patients without AGVA. Of 185 patients with AGVA, 77 had frequent PVCs, 45 had NSVT, and 63 patients had both. The average age of both groups was 65 ± 9.7 years. Patients were followed for 34 ± 10 months, and in 30 patients ambulatory monitoring was repeated at the end of the follow-up. Results: Fifteen AGVA and nine control patients died. In each group seven deaths were noncardiac. Six nonsudden and two sudden cardiac deaths (SCD) occurred in the AGVA group at 2-36 months after CABG and two nonsudden cardiac deaths in the control group at 3 and 35 months after CABG (p = 0.053). Both SCDs occurred 33 months after CABG after new events known to predispose to SCD. In 18 of 30 patients AGVÀ was no longer present when ambulatory ECG monitoring was repeated 36 ± 11 months after CABG. Conclusions: AGVA after CABG was not a marker of an early sudden cardiac death. In 60% of patients not treated with antiarrhythmic drugs, AGVA was no longer present late after operation.     

Acute ischemic syndromes following coronary artery bypass graft surgery

Coronary artery bypass graft (CABG) surgery, performed for the control of angina pectoris, leads to postoperative relief from symptoms in most patients. Amelioration of ischemia and improvement in exercise capacity after CABG are well documented. However, patients currently undergoing CABG are more complex than in the past—they are older and are maintained on medical therapy for longer periods. A large number of these patients have had one or more previous myocardial revascularization procedures. The postoperative period would appear to be a time of vulnerability for coronary events. However, previous investigators have focused on the pre- and intraoperative aspects of peri-CABG ischemia. Outcome data suggest that the postoperative interval is at least equally important as a determinant of short- and long-term morbidity and mortality. We discuss the epidemiology, etiology, pathophysiology, and treatment of ischemic syndromes in the postoperative period after CABG. In addition, we review recent data from a series of 14 patients, observed at our institution, who underwent cardiac catheterization and, in some cases, angioplasty of the culprit vessel in the immediate postoperative period.     

Delayed recovery of severely "stunned" myocardium with the support of a left ventricular assist device after coronary artery bypass graft surgery

A 53 year old man underwent repeat coronary artery bypass graft surgery after presenting with unstable angina. Because of intraoperative ischemia, the patient developed profound left ventricular dysfunction requiring placement of a left ventricular assist device and intraaortic balloon pump and catecholamine infusion. Serial radionuclide ventriculograms documented delayed recovery of the severely stunned myocardium with mechanical and pharmacologic support.