Atrial fibrillation after coronary artery bypass grafting without cardiopulmonary bypass.

OBJECTIVE: Atrial fibrillation is the most common complication after heart surgery. It rarely has a fatal outcome but causes patient instability, prolongs hospital stay, or even is the reason for perioperative infarction. Although conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass has excellent short-term and long-term results, the number of coronary operations on a beating heart without cardiopulmonary bypass is still growing. To reduce surgical trauma, off-pump coronary artery bypass grafting via sternotomy (OPCABG) or minimally invasive direct vision coronary artery bypass grafting (MIDCABG) via small thoracotomy are performed. The aim of this study was to estimate the frequency of atrial fibrillation in patients after myocardial revascularization without cardiopulmonary bypass. METHODS: A retrospective analysis of 48 patients undergoing myocardial revascularization without cardiopulmonary bypass was performed. Twenty-four patients underwent OPCABG and 24 were operated using the MIDCABG technique. The incidence of cardiac arrhythmias was analyzed since operation to the fourth postoperative day. Each patient had continuous ECG monitoring with option of arrhythmia analysis during ICU stay. After discharge from ICU 24-h ECG monitor studies were carried out. Surface 12-lead ECG was accomplished once a day, and additionally each time symptoms of cardiac arrhythmia occurred. Risk factors of atrial fibrillation were estimated. RESULTS: Atrial fibrillation occurred in 25% of patients after MIDCABG, in 29% after OPCABG, and in 18% after CABG with cardiopulmonary bypass. This difference has no statistical significance. Risk factors and incidence of postoperative complications were comparable in all groups. CONCLUSIONS: Atrial fibrillation is a common complication after procedures of myocardial revascularization, performed with or without cardiopulmonary bypass. The occurrence is not dependent on the type of operation.     

Atrial fibrillation after isolated coronary bypass surgery

Postoperative atrial fibrillation (Af) remains a significant source of morbidity after coronary artery bypass grafting (CABG). Prophylactic therapy with beta-adrenergic blockers or amiodarone hydrochloride is reported to reduce the incidence of Af. We studied the incidence of Af retrospectively and considered the risk factors for it. Ninety-three patients who underwent isolated CABG from April 2003 to March 2004 are included in this study. Postoperative Af was observed in 22 (25%) patients. Ten of them were operated on off-pump procedure, and 14 had any type of beta-adrenergic blockers preoperatively. The mean age of the group of postoperative Af is 69.7 +/- 9.2 years old (older than the non-Af group: 65.5 +/- 10 years old, p = 0.087). And the preoperative left atrial size was larger in the Af group than in the non-Af group (43.4 +/- 6.1 versus 40.6 +/- 5.4mm, p = 0.064) Major embolic complication occurred in only 1 (1.1%) patient of non-Af group. We observed postoperative Af in 25% of patients after CABG. Older age and larger left atrial size may relate to the incidence of Af, and appropriate anticoagulant therapy and medication of beta-blockers are important for the patients who have such risk factors.     

Atrial fibrillation after coronary artery bypass graft surgery is unrelated to cardiac abnormalities detected by transesophageal echocardiography.

Atrial fibrillation is a common complication of coronary artery bypass graft (CABG) surgery that is associated with adverse patient outcomes. We evaluated whether preexisting abnormalities of cardiac structure or function detected with transesophageal echocardiography (TEE) are prevalent in patients later developing atrial fibrillation after CABG surgery. TEE imaging was performed after induction of general anesthesia, but before primary CABG surgery, in 62 consecutive patients without cardiac valvular disease or preexisting atrial fibrillation. Measurements included left atrial diameter, left ventricular wall thickness, left ventricular end-systolic and end-diastolic dimensions and fractional area change. Pulsed-wave Doppler measurements of pulmonary venous and trans-mitral blood flow velocity were obtained. Continuous monitoring with telemetry electrocardiography for the development of atrial fibrillation was performed. Eighteen patients (29%) developed postoperative atrial fibrillation. There were no significant differences in left atrial or left ventricular TEE variables or pulsed-wave Doppler pulmonary venous flow measurements between patients with and without postoperative atrial fibrillation. After adjusting for age and duration of aortic cross-clamping, there were no differences in the transmitral Doppler diastolic filling variables between these same groups. These data suggest that atrial fibrillation commonly occurs after CABG surgery in the absence of atrial enlargement or Doppler-derived cardiac functional abnormalities. The data imply that the use of TEE immediately before surgery would be an insensitive means for routine identification of patients susceptible to this arrhythmia. Implications: Transesophageal echocardiography performed immediately before coronary artery bypass graft (CABG) surgery is not useful for prediction of susceptibility to develop atrial fibrillation postoperatively. Postoperative atrial fibrillation commonly occurs after CABG surgery in the absence of preoperative atrial enlargement or Doppler derived functional abnormalities.     

心肺转流心脏手术术后谵妄的预防

术后谵妄是手术后常见的神经系统并发症,表现为急性发作的注意力不集中、思维混乱和意识水平的改变等.心肺转流心脏手术患者的术后谵妄发生率明显高于其他类型手术,严重影响患者术后恢复和生存质量.尽管不能完全避免术后谵妄的发生,但有效的预防措施可以明显降低心肺转流心脏手术患者术后谵妄的发生率.本文章回顾近年来国内外术后谵妄的相关...     

Renal function changes after elective cardiac surgery with cardiopulmonary bypass

Cardiac surgery can either induce acute renal failure or improve GFR by improving the cardiac performance. In order to study renal function changes after elective cardiac surgery (CS) with cardiopulmonary bypass (CPBP), 21 patients undergoing valvular CS (VCS) or coronary artery bypass (CAB) were prospectively evaluated in three time periods: before, 24 hours after surgery and 48 hours after surgery. Patients were divided in 2 groups according to the GFR percent change in comparison to the baseline value found 24 hours after CS (deltaGFR24): Group 1, deltaGFR24 decrease higher than 20% (n = 11) and Group 2, deltaGFR24 decrease < or = 20% or deltaGFR24 increase (n = 10). In Group 1, 73% of the patients underwent VCS (p = 0.05 vs. Group 2) and all of them had previous VCS in sharp contrast with Group 2, where none of the patients had previous CS (p = 0.006). Patients in Group I required more volume replacement than Group 2 during the first 24 hours after CS: 2,699+/-704 mL versus 217+/-603 mL respectively, p = 0.019. Despite similar baseline GFR, Group 1 presented lower GFR 24 hours after CS when compared to Group 2 (39+/-5 versus 75+/-8 mL/(min x 1.73m2), p = 0.001) and a significantly different deltaGFR 48 hours after CS as compared to Group 2 (-21+/-11 versus +88+/-36%, p<0.01). Baseline sodium fractional excretion (FENa) in Group 1 was lower than in Group 2 (0.27+/-0.04 versus 0.70+/-0.12%, p = 0.01). No changes were observed after CS in urinary osmolality (Uosm) and urinary pH (UpH) in both groups. The deltaGFR24 showed positive correlation with baseline FENa (r = 0.44 p = 0.04) and negative correlation with volume balance during the first 24h after CS (r = -0.63, p = 0.007). More patients in Group 1 required nitroprusside than in Group 2 (66% vs. 14%, p = 0.04). Anesthesia time was shorter in Group 1 as compared to Group 2: 323+/-21 vs. 395+/-26 min, p = 0.04. No significant hemolysis occurred during CS in either group. There were no differences in age, gender, CPBP time, need for dopamine and/or dobutamine between the two groups. In conclusion, patients who presented GFR decrease after CS underwent VCS more frequently, had more prevalence of previous CS, presented lower baseline FENa, required more volume infusion and more nitroprusside use. On the other hand, no tubular dysfunction was detected in the early follow-up of CS. These results suggest that the observed renal function changes should be the result of an appropriated renal response to a low effective blood volume. In fact, a low baseline FENa anticipated a GFR decrease in these patients. Consistently, CAB patients that usually improve their cardiac output after surgery showed a clear GFR improvement.     

Anemia-associated acute kidney injury after cardiac surgery with cardiopulmonary bypass

Objective To investigate the incidence and to evaluate the risk factors of acute kidney injury (AKI) following cardiac surgery with cardiopulmonary bypass (CPB) at general hospitals. Methods A retrospective cohort database study was conducted, involving 233 patients who were scheduled to heart valve surgery or coronary artery bypass grafting (CABG) with CPB technique. Logistic regression was used to screen out the risk factors of AKI after the surgery. Results The study population, with an average age of 57±12 years (age 21 to 83) were investigated, there were 54(23.2%) diabetes patients, 105 (45.1%) hypertension patients, 21 (9%) chronic kidney disease (CKD) patients, and 51 (21.9%) anemia patients. Overall incidence of AKI was 32.2%. The Analysis Result indicates that preoperative CKD, anemia, hypoalbuminemia, left ventricular ejection fraction, intraoperative aortic block time, minimum mean arterial pressure, perioperative infection, and application of vancomycin are risk factors associated with postoperative AKI. Multiariable Logistic regression suggests that basic CKD (OR=9.498, P=0.001), anemia (OR=3.150, P=0.021), the LVEF before surgery (OR=1.733, P=0.045), intraoperative aortic block time (OR=2.227, P=0.026), and white blood cell (OR=3.357, P=0.032) were the independent risk factors of AKI. Conclusions AKI is a common complication following cardiac surgery with CPB. The patients with preoperative renal insufficiency, anemia, long intraoperative aortic block time and higher perioperative white blood cell count are subjected to a higher incidence of AKI. Alleviating patients’ anemia and reducing artery block of extracorporeal circulation time therefore might be potential means to mitigate the risks of AKI after cardiac surgery.     

Atrial fibrillation after cardiac surgery: pathophysiology and treatment

Atrial fibrillation (AF) occurs in 25% to 60% of patients after cardiac surgery. It is most consistently associated with advanced age and valvular heart operations. Despite improving knowledge of the pathophysiology of chronic AF, postoperative AF remains an obstinate clinical problem. It is associated with an increased risk of stroke, longer hospital stay, and higher hospital expenditure. Consequently, there has been great interest in strategies to prevent and treat this arrhythmia. Treatment for postoperative AF may require immediate electrical cardioversion for hemodynamically unstable patients. Heart rate control is useful in most patients, with anticoagulation considered after 48 hours. Antiarrhythmic therapy is often effective in restoring sinus rhythm but its use needs to be balanced against the patient's risk of proarrhythmic side effects such as torsade de pointes.     

High-dose cimetidine reduces proinflammatory reaction after cardiac surgery with cardiopulmonary bypass

Background. Cimetidine, which is usually used for gastric ulcer, enhances cellular immunity. The effect of cimetidine on perioperative proinflammatory response after cardiac surgery with cardiopulmonary bypass was investigated.

Methods. Elective coronary artery bypass graft cases in which CPB was performed were placed randomly in a cimetidine (C) group (n = 20) or a no-treatment (N) group (n = 20). The time course of plasma levels of neutrophil elastase, interleukin (IL)-6 and IL-8, leukocyte counts, lymphocyte recovery ratio, C-reactive protein, creatine-kinase-MB, and oxygenation index were analyzed.

Results. The plasma levels of neutrophil elastase and IL-8 were inhibited in the C groups at 2 hours after CPB termination. In a comparison of the two groups, the C group demonstrated higher lymphocyte recovery ratio and lower C-reactive protein on postoperative day 5 and shorter intubation time. No intergroup differences were observed in IL-6, leukocyte counts, creatine-kinase-MB levels, or oxygenation index.

Conclusions. Cimetidine may reduce surgical stress and augment the immune system after cardiac surgery with cardiopulmonary bypass.     

The systemic inflammatory response after cardiac surgery with cardiopulmonary bypass in children

Paediatric cardiac surgery often requires cardiopulmonary bypass (CPB) during the surgical intervention. CPB is known to elicit a systemic inflammatory response with activation of the complement and coagulation systems, stimulation of cytokine production, cellular entrapment in organs, neutrophil activation with degranulation, platelet activation, and endothelial dysfunction. These changes are associated with a risk of postoperative organ dysfunction and increased morbidity and mortality in the postoperative period. Clinical studies have concentrated on measurement of inflammatory markers and mediators in peripheral blood, where the systemic inflammatory response in the paediatric cardiac patient seems to be different from the adult case. Looking at the organ level, experimental studies have the advantage of providing information contributing to a better understanding of the pathological events that may lead to the deteriorated organ function. This review focuses on the systemic inflammatory response after cardiac surgery with CPB in children and experimental CPB models.     

体外循环下心脏手术肺保护策略

背景 肺损伤是心脏手术体外循环(cardiopulmonary bypass,CPB)的主要并发症之一,肺保护一直是临床、实验研究热点.目的 为CPB下心脏手术肺保护提供参考.内容 就近年来心脏手术CPB期间通气策略和麻醉药物、CPB设备和技术、肺动脉灌注技术、药物干预对肺保护作用的进展进行综述.趋向 CPB下心脏手术...     

Peripheral blood monocyte activation during coronary artery bypass grafting with or without cardiopulmonary bypass

Objective. The aim of this prospective, randomized study was to investigate the impact of coronary artery bypass grafting (CABG) on peripheral monocytes and to evaluate the additional effect of cardiopulmonary bypass (CPB).

Design. Twenty patients admitted for elective CABG were randomized to either on-pump (ONCAB, n=9) or off-pump (OFFCAB, n=11) surgery and blood samples were drawn before, during and 24 h after the operation. The total number of monocytes and the proportion of the more mature CD16⁺/CD14⁺ monocytes were measured. Expression of activation markers (CD11b, CD35 and CD62L) and oxidative burst were determined using flow cytometry on both resting and in vitro stimulated cells. Serum concentrations of soluble CD14 and monocytes/macrophage chemotactic protein 1 (MCP-1) were analysed.

Results. During surgery there was a selective decrease in the proportion of CD16⁺/CD14⁺ monocytes compared to total monocytes. These had returned to preoperative values 24 h after surgery while the total number of monocytes had increased more than 100%. Intracellular production of oxygen free radical H₂O₂ was increased in the ONCAB group during surgery compared to OFFCAB. Monocyte expression and in vitro mobilization of complement receptors, CD11b and CD35, were similar in both study groups during and after surgery as was the expression of CD62L. Serum levels of MCP-1 decreased during surgery as did soluble CD14, both with increased levels again the day after surgery.

Conclusion. It is concluded that the circulating monocyte population is activated during and as a consequence of CABG. There were few apparent additional effects of CPB found in this study. In this setting the inflammation caused by the surgery procedure per se probably surpasses the impact of the CPB on circulating blood monocytes.     

Peripheral blood monocyte activation during coronary artery bypass grafting with or without cardiopulmonary bypass

OBJECTIVE: The aim of this prospective, randomized study was to investigate the impact of coronary artery bypass grafting (CABG) on peripheral monocytes and to evaluate the additional effect of cardiopulmonary bypass (CPB). DESIGN: Twenty patients admitted for elective CABG were randomized to either on-pump (ONCAB, n = 9) or off-pump (OFFCAB, n = 11) surgery and blood samples were drawn before, during and 24 h after the operation. The total number of monocytes and the proportion of the more mature CD16+/CD14+ monocytes were measured. Expression of activation markers (CD11b, CD35 and CD62L) and oxidative burst were determined using flow cytometry on both resting and in vitro stimulated cells. Serum concentrations of soluble CD14 and monocytes/macrophage chemotactic protein 1 (MCP-1) were analysed. RESULTS: During surgery there was a selective decrease in the proportion of CD16+/CD14+ monocytes compared to total monocytes. These had returned to preoperative values 24 h after surgery while the total number of monocytes had increased more than 100%. Intracellular production of oxygen free radical H2O2 was increased in the ONCAB group during surgery compared to OFFCAB. Monocyte expression and in vitro mobilization of complement receptors, CD11b and CD35, were similar in both study groups during and after surgery as was the expression of CD62L. Serum levels of MCP-1 decreased during surgery as did soluble CD14, both with increased levels again the day after surgery. CONCLUSION: It is concluded that the circulating monocyte population is activated during and as a consequence of CABG. There were few apparent additional effects of CPB found in this study. In this setting the inflammation caused by the surgery procedure per se probably surpasses the impact of the CPB on circulating blood monocytes.     

Two unusual complications associated with cardiopulmonary bypass for pediatric cardiac surgery detected by transesophageal echocardiography after decannulation

We describe two rare cases of complications associated with cannulation for cardiopulmonary bypass during pediatric cardiac surgery detected by transesophageal echocardiography (TEE). The first patient (a 20-month-old boy, 11 kg) was scheduled for complete repair of an atrial septal defect and partial anomalous pulmonary venous connection. After decannulation of the superior vena cava, a mosaic jet was observed by means of TEE. The second patient (an 11-month-old boy, 6.4 kg), with a double outlet right ventricle, was scheduled for a hemi-Fontan procedure. After decannulation of the ascending aorta, high blood flow velocity of 4 m·s⁻¹ was detected by TEE. Intraoperative TEE was useful for early detection of complications associated with cardiopulmonary bypass cannulation during pediatric cardiac surgery.