Effectiveness of bi-atrial pacing for reducing atrial fibrillation after coronary artery bypass graft surgery.

Atrial fibrillation (AF) is common after cardiac surgery and adds significant cost and morbidity. The use of prophylactic pacing strategies to prevent post-operative AF has been controversial. We previously performed a pilot study which suggested that the combination of beta-blockers and bi-atrial pacing (BAP) may reduce AF after cardiac surgery. We prospectively randomized 118 patients to continuous BAP for up to 96 hours post-operatively versus standard therapy. All patients were treated with beta-blockers as tolerated. Patients were paced in the AAI mode at a rate of 100 pulses per minute. The primary endpoint of the study was the occurrence of sustained AF (>10 minutes). There was a significant reduction in the incidence of AF in the BAP group among patients undergoing coronary artery bypass graft surgery with or without aortic valve replacement (35 % vs. 19 % AF; OR=0.38, 95 % CI 0.15, 0.93; p <0.05). Including patients undergoing isolated aortic valve surgery (n=7), there remained a strong trend toward a reduction of AF with pacing (no atrial pacing [NAP] vs. BAP; 35 % vs. 21 % AF; OR=0.48, 95 % CI 0.21, 1.11; p=0.08). Patients age 70 or greater benefited most from pacing (NAP vs. BAP; 55 vs. 25 % AF; p<0.05), while those less than 70 years of age did not (17 vs. 18 % p=NS). There was a significant reduction in the amount of time spent in the intensive care unit among patients receiving BAP (50+/-40 vs. 37+/-25 h; p<0.05).BAP together with beta-blockade after coronary artery bypass graft surgery reduces the incidence of post-operative atrial AF. Elderly patients (age 70 or greater) appear to benefit most, and may be a group to whom this therapy should be targeted.

Scanning electron microscopic analysis of endoscopic versus open vein harvesting techniques.

BACKGROUND: Endoscopic vein harvesting techniques are increasingly used for obtaining conduit for coronary artery bypass surgery. Although they offer advantages in healing over the conventional open technique, concern has been raised regarding the potential for trauma to the vein in the form of intimal disruption which would theoretically predispose to early graft thrombosis and/or development of stenoses. Unfortunately no long term data is yet available for determining if conduits harvested in this fashion are prone to such events. METHODS: We have examined vein segments harvested by both endoscopic and open techniques for evidence of intimal injury (either visible disruption of the intima and/or presence of thrombus) using scanning electron microscopy (SEM). Those harvesting the vein were unaware which patients were in the study, and both the SEM technician and cardiac pathologist who evaluated the scans were blinded to the technique used for harvesting. For each vein segment examined, views were obtained of four different sections and were analyzed at magnifications ranging from 10 yen to 100 yen. RESULTS: Both thrombus formation and visible intimal disruption were identified quite rarely, and overall were not linked significantly to the type of harvesting technique used. CONCLUSIONS: These results suggest that endoscopic vein harvesting techniques do not subject the conduits to more trauma than open techniques and therefore may not predispose to the development of earlier stenoses. This data will need to be confirmed by both other methods of identifying intimal injury and by long-term follow-up of conduit patency in both groups.

The use of smaller, more flexible chest drains following open heart surgery : an initial evaluation.

STUDY OBJECTIVES: To evaluate the safety and efficacy of smaller-caliber drains in patients undergoing open heart surgery. DESIGN: A retrospective analysis of the medical records and chest radiographs assembled data on total amount of drainage, number of days of drainage, length of postoperative stay, appearance of postoperative chest radiographs, and need for further drainage from either the pleural or pericardial spaces. SETTING: A large university-based teaching hospital, where > 800 open-heart procedures are performed yearly. PATIENTS AND INTERVENTIONS: A total of 202 patients underwent standard open heart surgery by one surgeon, and postoperative pleural and pericardial decompression was undertaken using small caliber, more flexible drains connected to bulb suction. RESULTS: Tubes were left in an average of 2.4 days, with a mean of 826.7 mL collected during that time. The average postoperative length of stay was 6.7 days (median, 5 days). At or before 6-week follow-up, chest radiographs revealed moderate or large effusions in 19 patients (9.4%) in a pleural space that had been drained postoperatively. Twelve patients (5.9%) required an additional postoperative procedure for pleural drainage (eight thoracenteses, four tube thoracostomies). Four patients (2.0%) required reexploration of the pericardium for tamponade. CONCLUSIONS: Use of smaller-caliber drains have been found at our institution to be an adequate means of decompression of the pleural and pericardial spaces following open heart surgery, with patients rarely having clinically significant pleural effusions at 6-week follow-up.

Off-pump versus on-pump coronary artery bypass surgery: a case-matched comparison of clinical outcomes and costs.

BACKGROUND: Results of off-pump coronary artery bypass (OPCAB) surgery have demonstrated trends toward fewer complications, faster recoveries and lower costs compared with on-pump coronary artery bypass (ONCAB) surgery. The validity of such comparisons, however, may be impacted by differences in preoperative risk factors between the two surgeries. METHODS: A total of 76 OPCAB surgery patients were case-matched (by age, sex and Society of Thoracic Surgeons' risk scores) with an equal number of patients who underwent ONCAB surgery by the same surgeon. Postoperative clinical parameters (time on mechanical ventilation, number of blood transfusions, peak cardiac enzyme levels and metabolic acidosis) and outcomes data (intensive care unit and overall in-hospital lengths of stay, perioperative myocardial infarction, atrial fibrillation, stroke, reoperation for bleeding and mortality) were analyzed, and the variable and total costs for each patient were calculated. RESULTS: OPCAB patients required less mechanical ventilation and fewer blood transfusions and had lower peak creatinine phosphokinase levels, as well as a reduced incidence of metabolic acidosis. There were trends toward both shorter intensive care unit and overall in-hospital lengths of stay for OPCAB patients. The average total cost for this group was 20.5% less than for ONCAB patients. There were no differences in rates of atrial fibrillation, myocardial infarction, reoperation for bleeding, stroke or mortality. CONCLUSIONS: By reducing the need for mechanical ventilation, transfusions and intensive care unit and overall in-hospital lengths of stay, OPCAB surgery decreases the use of limited and costly resources without increasing risks. These advantages do not appear to be related to patient selection.

Massachusetts Risk Management Survey (MaRMS) of teaching hospital physicians.

OBJECTIVE: To assess and compare the risk management knowledge of physicians from Massachusetts teaching hospitals. DESIGN: A survey. SETTING: Participating Massachusetts teaching hospitals. PARTICIPANTS: 639 of some 2,000 staff physicians of participant hospitals who were sent surveys. An additional 174 postgraduate year 1 (PGY1) and PGY3 house officers also completed the survey. MAIN OUTCOME MEASURES: Percent of questions answered correctly, and comparisons between staff physicians and house officers. RESULTS: Staff physicians scored higher (87%) than PGY1s and PGY3s combined (81%), P<0.001. Scores among staff physicians did not differ according to field of medicine, age, proportion of time spent in clinical practice, or years in practice. PGY3s did not score significantly higher than PGY1s (82% vs. 80%). Some 40% of physicians said they ordered more tests than necessary because of malpractice worries; they indicated 72% of their colleagues do so as well. Physicians in obstetrics-gynecology and emergency medicine were more likely to respond yes to this question than physicians in other fields of medicine (P<0.001), as were physicians who had been defendants in a malpractice suit (88 P=0.013). CONCLUSIONS: Surveyed staff physicians have an adequate risk management knowledge. Training directors should encourage house officers to attend risk management programs to improve their knowledge. Physicians might overestimate the amount spent on defense medicine based on their perceptions of other physicians.

Reduction of bleeding after heart operations through the prophylactic use of epsilon-aminocaproic acid.

UNLABELLED: Excessive postoperative bleeding after heart operations continues to be a source of morbidity. This prospective double-blind study evaluated epsilon-aminocaproic acid as an agent to reduce postoperative bleeding and investigated its mode of action. One hundred three patients were randomly assigned to receive either 30 gm epsilon-aminocaproic acid (51 patients) or an equivalent volume of placebo (52 patients). In a subset of these patients (14 epsilon-aminocaproic acid, 12 placebo), tests of platelet function and fibrinolysis were performed. RESULTS: By multivariate analysis, three factors were associated with decreased blood loss in the first 24 hours after operation: epsilon-aminocaproic acid versus placebo (647 ml versus 839 ml, p = 0.004), surgeon 1 versus all other surgeons (582 ml versus 978 ml, p = 0.002), and no intraaortic balloon versus intraaortic balloon pump use (664 ml versus 1410 ml, p = 0.02). No significant differences in platelet function could be demonstrated between the two groups. Inhibited fibrinolysis, as reflected by less depression of the euglobulin clot lysis and no rise in D-dimer levels, was significant in the epsilon-aminocaproic acid group compared with the placebo group. CONCLUSION: The intraoperative use of epsilon-aminocaproic acid reduces postoperative cardiac surgical bleeding.

Simultaneous repair of multiple traumatic aortic tears.

A 34-year-old man suffered simultaneous tears of his distal ascending and mid-descending thoracic aorta secondary to blunt trauma. Repairs of both injuries were performed via a median sternotomy approach followed by a left lateral thoracotomy using two separate methods of cardiopulmonary bypass.

Arrhythmias and conduction disturbances after coronary artery bypass graft surgery: epidemiology, management, and prognosis.

CABG is associated with many perioperative complications, including supraventricular and ventricular arrhythmias and conduction disturbances. Atrial fibrillation occurs in < or = 40% of patients after CABG and is especially common in older patients. Although it is often benign and self-limited, it can lead to complications such as stroke. Treatment consists primarily of control of the ventricular response rate; in some cases, antiarrhythmic drugs or electrical cardioversion are needed. Anticoagulation should be considered in appropriate cases of persistent (48 to 72 hours) atrial fibrillation after initial treatment. Prophylaxis, especially with beta-blocking agents, seems to be effective and should be considered in appropriate cases. Simple ventricular arrhythmias are common after CABG and do not affect the patient's prognosis; however, sustained VT/VF occur infrequently (< 2% of patients) and carry a high mortality rate. Treatment is aimed at correcting precipitating factors (e.g., myocardial ischemia). Electrophysiologically guided drug therapy and implantation of an ICD should be considered in appropriate cases for patients who survive the initial events. Transient minor conduction disturbances are common after CABG; in some patients persistent AV block and sinus node dysfunction develop and may require treatment with permanent pacemaker.

Ceruloplasmin and copper transport during the latter part of gestation in the rat.

We have examined the tissue uptake of 67Cu from ceruloplasmin versus albumin and transcuprein, after its intravenous administration to pregnant rats, in the last 4 days of gestation. 67Cu infused as in vivo-labeled ceruloplasmin remained on ceruloplasmin in the maternal circulation over the 4- to 6-hr time period examined, as determined by gel chromatography and immunoreactivity. That infused as in vitro-labeled serum was initially on transcuprein and albumin but soon also with new ceruloplasmin. On the basis of percent dose as well as total actual Cu transferred (taking into account the sizes of the two plasma Cu pools), ceruloplasmin was the preferred source of Cu for most tissues. Total uptake of Cu from ceruloplasmin was seven times greater than that from albumin and transcuprein for the placenta, whole fetus, and fetal liver. It was 2- to 6-fold greater for other tissues (except liver and kidney). When synthesis of maternal 67Cu-ceruloplasmin (from 67Cu administered on albumin and transcuprein) was inhibited with cycloheximide, uptake by nonhepatic tissues was reduced markedly. In the fetal circulation, entering 67Cu was initially associated with transcuprein and alpha-fetoprotein (or albumin), but then also appeared with ceruloplasmin. Specific receptors for ceruloplasmin were detected on membranes from the placenta as well as fetal liver; mRNA for ceruloplasmin was detected on the endoplasmic reticulum-bound polyribosomes of placenta/yolk sac, and of fetal and maternal liver. We conclude that Cu destined for the fetus is delivered mainly or exclusively by ceruloplasmin. It may enter via placental receptors, arriving in fetal plasma in ionic form, for later incorporation into fetal ceruloplasmin. The importance of ceruloplasmin as a source of plasma Cu for nonhepatic organs is also confirmed.

Exclusion of cervical spine injury: a prospective study.

Trauma room lateral cervical spine radiographs (LCSR) may improve the safety of intubation and transportation of multiply injured patients by providing earlier recognition of spinal vertebral injuries. We prospectively evaluated 60 consecutive trauma admissions to determine the impact of clearance of cervical spine radiographs on patient care. Fifty-three patients had no cervical spine injury (CSI). Intubations, emergency head CT scan, aortography, or urgent operation (less than 6 hours after admission) were required in the majority of patients and preceded complete cervical spine clearance in all but one instance. The median time for radiologic clearance of the cervical spine was 15 hours (range, 1.5 to 181). LCSR failed to identify three of the seven acute CSI (all three had C7 fractures). The spine-injured were managed with cervical collars and no new neurologic injury developed. We conclude that: 1) LCSRs do not appear to alter urgent management of multiply injured patients during resuscitation and transportation; 2) chest radiographs and emergency investigations should not be delayed by repeated LCSR in the trauma room as it may be difficult to fully exclude CSI in many trauma patients; 3) we support the current ATLS guidelines, which suggest that all patients should be presumed to have an unstable CSI until the presence of cervical injury has been excluded.