Esmolol versus diltiazem in the treatment of postoperative atrial fibrillation/atrial flutter after open heart surgery.

BACKGROUND: Supraventricular tachyarrhythmias are common after open heart surgery. Possible causative factors for these arrhythmias include operative trauma, atrial ischemia, electrolyte imbalances, pericardial irritation, and excess catecholamines. Two agents commonly used to control ventricular rate in atrial fibrillation or atrial flutter (AF/AFL) are beta-blockers and calcium channel blockers. METHODS AND RESULTS: This randomized study was designed to compare the safety and efficacy of intravenous diltiazem versus intravenous esmolol in patients with postoperative AF/AFL after coronary bypass surgery and/or valve replacement surgery. A comparative cost analysis was also performed. Thirty patients received either esmolol (n = 15) or diltiazem (n = 15) for AF/AFL. During the first 6 hours of treatment, 66.6% of esmolol-treated patients converted to sinus rhythm compared with 13.3% of the diltiazem-treated patients (P <.05). At 24 hours, 66.6% of the diltiazem group converted to SR compared with 80% of the esmolol group (not significant). Drug-induced side effects, time to rate control (<90 beats/min), number of patients requiring cardioversion, and length of hospitalization were similar for the two groups. The drug cost/successfully treated patient for esmolol versus diltiazem was $254 versus $437 at 6 hours and $529 versus $262 at 24 hours. CONCLUSIONS: Although this is a small study, it suggests that esmolol is more effective in converting patients to normal sinus rhythm than diltiazem during the initial dosing period. No differences in conversion rates were observed between the two groups after 24 hours. Additional studies are needed to confirm whether esmolol is the initial drug of choice in patients with postoperative AF/AFL after coronary bypass surgery.

Lung herniation secondary to minimally invasive direct coronary artery bypass grafting.

Lung herniation after thoracotomy is rare. We report a 66-year-old man who presented with this complication after undergoing attempted minimally invasive direct coronary artery bypass grafting. The defect was repaired with a composite of Marlex mesh and methyl methacrylate.

Appropriate timing of elective coronary artery bypass graft surgery following acute myocardial infarction.

BACKGROUND: The appropriate timing of elective coronary artery bypass surgery (CABG) following acute myocardial infarction (AMI) remains uncertain. It is hypothesized that a waiting period allows the myocardium to recover prior to revascularization, thus decreasing morbidity and mortality. This study was designed to determine if a waiting strategy is justified following AMI in patients requiring elective CABG. METHODS: Between 1994 and 1996, 214 patients underwent isolated, nonrepeat, elective CABG. Three groups were evaluated: group I, control, 155 patients with no AMI; group 11, 39 patients with nontransmural AMI; and Group III, 20 patients with transmural AMI. Demographics, intraoperative, and postoperative variables were collected and compared among all groups. RESULTS: Groups were well-matched demographically: group I, patients waited an average of 2.3 days in hospital prior to operation; group II, an average of 4.2 days; and group III, an average of 5.2 days. Except for the use of inotropes, group I 34%, group 11 39%, and group III 70% (P = 0.007), and the intra-aortic balloon pump, group I 0%, group 11 8%, and group III 25% (P = 0.001). There were no differences in complications. Importantly, there was no difference in mortality or postoperative length of stay. The mortality in group I was 2.6%, in group 11 2.6%, and in group III 0%. The length of stay in groups I and II was 8.5 days, and in group III, 8.1 days. CONCLUSION: A waiting period of 3 to 5 days after a nontransmural AMI and 5 to 7 days after a transmural AMI can produce similar postoperative results to non-AMI patients undergoing CABG. Thus, a waiting strategy to allow the myocardium to recover is justified.

Detection of scalene lymph node metastases from lung cancer. Positron emission tomography.

Preliminary data indicate that positron emission tomography (PET) following injection of fluorodeoxyglucose F18 (FDG) is sensitive and specific for detecting malignant cells in chest tumors and mediastinal lymph nodes. We report a case of non-small cell lung cancer metastatic to clinically normal scalene lymph nodes that was correctly staged by FDG-PET.

Positron emission tomography of lung tumors and mediastinal lymph nodes using [18F]fluorodeoxyglucose. The Members of the PET-Lung Tumor Study Group.

Positron emission tomography detects increased glucose uptake in malignant tissue using the glucose analogue [2-18F]fluoro-2-deoxy-D-glucose. We reviewed the scans obtained in 62 patients with lung tumors. All had undergone computed tomography and had tissue-based diagnoses: 22 had adenocarcinomas, 12 had squamous cell carcinomas, 13 had other malignancies, 1 had organizing pneumonia, 1 had a hamartoma, and 13 had granulomas. Positron emission tomography with [2-18F]fluoro-2-deoxy-D-glucose identified 44 of 47 malignancies. Two of three false-negative findings were tumors that were 1 cm2 or less and the other was a bronchioloalveolar carcinoma. All three false-positive findings were granulomas. The sensitivity and specificity of the technique were 93.6% and 80%, respectively, and the positive and negative predictive values were 93.6% and 80%, respectively. The differential uptake ratio was determined in all 62 patients. The mean differential uptake ratio (+/- the standard error of the mean) for malignant tumors was 6.4 +/- 0.56 and that for benign tumors was 1.14 +/- 0.26 (p < 0.0001, t test). Twenty-five of the patients had N2 lymph nodes evaluated pathologically. Positron emission tomography with [2-18F]fluoro-2-deoxy-D-glucose identified negative N2 nodes in 19 of 22 patients (86%) with negative nodes and positive N2 nodes in 2 of 3 patients (66%) with positive nodes, including one instance missed by computed tomography.(ABSTRACT TRUNCATED AT 250 WORDS)

Simple method for cardioplegia retrieval in patients with chronic renal failure.

A case in which a retrograde cardioplegia catheter was inserted into the coronary sinus for retrieval of antegrade cardioplegia in a patient with chronic renal failure is described. Potassium levels were maintained within normal limits throughout the procedure.

Percutaneous cardiopulmonary support in cardiac arrest.

Of 11 patients who underwent emergency resuscitation from cardiac arrest using a system of percutaneous cardiopulmonary support (CPS), two (18%) were long-term survivors. Percutaneous cardiopulmonary support was instituted without complication in all patients, with flows ranging from 1.8 to 5.5 L/min; the average duration of support was 304.3 min. All four patients who underwent emergency surgery (two coronary revascularization, one mitral valve revascularization, one mitral valve replacement with coronary revascularization, and one primary left ventricular assist device insertion) died. One patient died while on CPS secondary to irreversible ventricular arrhythmias after a successful percutaneous transluminal coronary angioplasty (PTCA). Six patients were weaned from the support system, three of whom had undergone PTCA while on CPS. The two survivors were the youngest patients (33 and 24 years). One of them had severe hypothyroidism as the cause of cardiac arrest, and the second was a hypothermia patient who was in ventricular fibrillation for 2 hr before establishing CPS. In comparing survivors (two) to nonsurvivors (nine), a significant difference (p = 0.034) in age was found, with survivors being younger. There was also a difference in incidence of atherosclerotic cardiovascular disease (p = 0.018), with survivors having none. There was no difference in the time to CPS (p = 0.905) or time on CPS (p = 0.156). Cardiopulmonary support can be instituted, resulting in excellent stabilization in patients with cardiac arrest. Survivors tended to be young and not have atherosclerotic cardiovascular disease (ASCVD) as their primary diagnosis. Neither length of cardiac arrest before CPS nor time on support correlated with a poor outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Pericardial window: mechanisms of efficacy.

Although the term implies a persistent communication through which fluid might drain, how a pericardial window works is not clear. We believe that the mechanism of success is not window but rather fusion of the epicardium to the pericardium with obliteration of the potential space. To evaluate this, we studied 28 patients, all of whom underwent a subxiphoid pericardial window procedure with tube drainage maintained until output was minimal. There were no operative deaths, and 26 patients (92.9%) obtained permanent relief. Postoperative echocardiograms demonstrated thickening of the pericardium/epicardium and obliteration of the pericardial space. Autopsy performed on 4 patients who died of their underlying malignancy confirmed this fusion, which begins as an inflammatory process. A subxiphoid pericardial window relieves effusions with a low operative mortality and good long-term success (92.9%, 26 of 28). This success is dependent on the inflammatory fusion of the epicardium to pericardium and not maintenance of a window. Tube decompression should be maintained until fluid output is minimal to allow apposition and fusion of the two surfaces.

Pericardial cells for graft seeding: isolation, culture and identification.

The purpose of this study was to determine the feasibility of using the pericardium as a source of endothelial cells. Nineteen pieces of fresh pericardium were obtained from nine mongrel dogs. Cells were prepared by collagenase digestion of the pericardium for 24 minutes followed by centrifugation. The cells were divided into three groups: The supernatant subjected to no further steps, Group I (N = 6); filtration through a 15 micron porous mesh, Group II (N = 6); and Percoll gradient separation with medium 199, Group III (N = 7). The cells obtained were cultured for seven days in tissue culture media. Yield (cells x 10(5)/gram fresh tissue) was determined with Methods I, II, and III, producing 32.4 +/- 25.9 (SD), 0.96 +/- 0.6 and 0.57 +/- 0.5, respectively (I vs II or III, p less than 0.01). Fibroblast contamination determined by phase contrast light microscopy was demonstrated in 6/6 cultures with Method I, 3/6 with II and 1/7 for III (I vs III, p less than 0.01). An assay for endothelial cells (Factor VIII) was positive in 2/6 cultures with Method I, 5/6 with II and 7/7 for III (I vs III, p less than 0.01). The pericardium is a suitable organ for procurement of endothelial cells. Though reducing yield, filtration and Percoll gradient separation allows for isolation of a relatively pure culture of endothelial cells.

Seeding with endothelial cells derived from the microvessels of the omentum and from the jugular vein: a comparative study.

Segments of an experimental polytetrafluoroethylene graft (9 cm long, 6 mm I.D.) of high porosity were implanted in 25 dogs as aortic interposition grafts. Nine grafts were seeded with a mean of 7 x 10(5) viable endothelial cells (ECs) derived from the jugular vein (group A) and eight were seeded with a mean of 7 x 10(5) viable ECs derived from the microvessels of the omentum (group B). Eight grafts were not seeded and they served as controls (group C). Animals were put to death 5 weeks after graft implantation. The thrombus-free area was measured at 81% +/- 10% in group A, 65% +/- 22% in group B, and 25% +/- 13% in group C (p less than 0.05, group A vs group B; p less than 0.05, group B vs group C). The thickness of the subendothelial layer was 151 +/- 60 microns in group A, 280 +/- 60 microns in group B, and 100 +/- 75 microns in group C (p less than 0.001, group B vs groups A and C). The production of 6-keto-PGF1 alpha in the presence of sodium arachidonate was higher in seeded grafts (p less than 0.05). Omentally derived microvessel ECs can be seeded in vascular grafts; refinements in the technique of EC procurement are required to minimize contamination and to obtain ECs with more effective biologic activity.