Myocardial metabolism altered by ischemic preconditioning and enflurane in off-pump coronary artery surgery.

OBJECTIVE: During off-pump coronary artery bypass (OPCAB) surgery, the heart is subjected to ischemia and reperfusion. The authors hypothesized that the volatile anesthetics are as effective as ischemic preconditioning (IPC) in preserving myocardial function during off-pump cardiac surgery, and this effect is because of multiple mechanisms of action. Therefore, the effects of enflurane with its calcium inhibition and antioxidative properties were compared with mechanical IPC in preserving myocardial cellular markers. DESIGN: A prospective, randomized, controlled, and partly blinded study. SETTING: A tertiary care university hospital. PARTICIPANTS: Twenty-five patients undergoing elective single-graft OPCAB surgery. INTERVENTIONS: Patients were randomized into 3 groups: (1) control (n = 8), (2) a single 5-minute ischemia/reperfusion interval of IPC before coronary occlusion (n = 9), and (3) 1.6% enflurane anesthesia 15 minutes before and during graft attachment (n = 8). Arterial and coronary sinus venous blood were analyzed for biochemical indices of ischemia and hydroxyl radical generation. MEASUREMENTS AND MAIN RESULTS: Although the hemodynamic changes were small, myocardial lactate production in the control group increased by 120%, whereas in the enflurane group it decreased significantly (p < 0.01) compared with the control and IPC groups. Oxygen utilization in the control group was 44% higher (p < 0.03), and there was also a larger release of the hydroxyl radical-dependent adduct 2,3-dihydroxybenzoic acid (225% increase, p < 0.05) compared with both study groups. During reperfusion, initial anterior wall hypokinesis by TEE was observed, with slow recovery during reperfusion compared with early recovery in both study groups. CONCLUSIONS: Coronary occlusion during OPCAB surgery results in increased production of ischemia-related metabolic products. The application of methods such as IPC or volatile anesthesia appears to reduce the metabolic deficit, free-radical production, and physiologic changes.

Undifferentiated sarcoma of the pulmonary artery mimicking pulmonary thromboembolic disease.

Primary pulmonary artery sarcoma is an uncommon tumor. Mandelstamm in 1923 was the first to describe the disease in an autopsy. Since then, less than 200 cases were reported. The incidence is 0.001-0.03%, they are always highly malignant sarcoma, and women are involved twice as often as men. The presentation is often cough, dyspnea, and chest pain, and patients are usually diagnosed as suffering from pulmonary emboli, and primary tumor of the pulmonary artery is not usually considered in the differential diagnosis. The diagnosis of pulmonary artery sarcoma is made of the "clot" resected during pulmonary artery thrombendarterectomy. Our suggestion is that in patients with unilateral pulmonary artery occlusive disease, no evidence of positive hypercoagulability tests, and no history of thromboembolism, a high suspicion of pulmonary artery sarcoma should be kept in mind, and an angiographic-guided biopsy from the intra-arterial occlusive material should be considered. The treatment is surgery. The survival without operation is less than 2 months. Some patients were treated with adjuvant chemotherapy. We report on a woman with undifferentiated sarcoma of the pulmonary artery, mimicking chronic pulmonary artery emboli. This case illustrates the need to consider malignancy in the differential diagnosis of patients having pulmonary emboli.

Symptomatic myocardial bridging in a child without hypertrophic cardiomyopathy.

Myocardial bridging (MB) is a rare coronary anomaly in children that is typically associated with hypertrophic cardiomyopathy or left ventricular hypertrophy. Several reports, mainly in adults, have suggested an association between MB and sudden death or ischemia without other cardiac abnormalities. In this report, we describe an 11-year-old girl with syncope and manifestations of cardiac ischemia associated with MB of the middle segment of the left anterior descending artery. The coronary anomaly was not associated with left ventricular hypertrophy. Surgical unroofing of the affected coronary artery segment resulted in complete recovery. MB should be included in the differential diagnosis of children presenting with syncope and signs of ischemia even in the absence of ventricular hypertrophy.

Repair of anomalous pulmonary artery with interposition graft: midterm results.

Anomalous pulmonary artery arising from the aorta is a rare congenital anomaly. The midterm results of repair of this malformation by Gore-Tex graft interposition were examined in 5 patients: 3 with anomalous right pulmonary artery and 2 with anomalous left pulmonary artery from the ascending aorta. Echocardiography was adequate in 4 cases for diagnosis, planning the operation, and follow-up. Angiography was needed for diagnosis in one case where the echocardiographic findings were unclear. The mean follow-up period was 4 years. One patient with tracheoesophageal fistula and cardiac malformation died 2 months after the operation due to multi-organ failure. Three patients needed re-operation because of graft narrowing, and one was without problems 5.2 years postoperatively. In anomalous pulmonary artery from the ascending aorta, repair should be performed as early as possible to prevent pulmonary hypertensive changes. When the anomalous pulmonary artery cannot be anastomosed directly to the main pulmonary artery, an interposition graft can be placed safely without cardiopulmonary bypass. With appropriate follow-up, this can be a satisfactory solution, although it carries the risk of re-operation due to graft narrowing.

[Surgical intervention in infective endocarditis: indications and timing].

A major advance has occurred over recent decades in the treatment strategies for infective endocarditis (IE). A significant part of this progress is due to a clearer knowledge of IE insult patterns; especially those concerning valvular damage and resultant heart failure. Furthermore, the existence of IE unique vegetations ensuring a suitable platform for organism growth and partial antibiotic resistance, has led to an understanding of the limited capacity of antibiotics to treat IE. Accordingly, an increased emphasis on surgical intervention has emerged. Indeed, the last decades were characterized by increased attempts to explore the feasibility and efficacy of surgical approach in IE. The present review is a result of these attempts, summarizing the major indications for surgical intervention in IE, as was recently published by the American Heart Association. Generally, such intervention is warranted in IE complications including: hemodynamically significant valvular damage, paravalvular abscess, continuous infection despite optimal treatment, recurrent emboli and antibiotic-resistant organisms. Recognition of the prognostic influence of pre-treatment heart failure degree has led to the development of early surgical intervention, namely, surgical intervention during the active period of IE. Application of such early intervention has led to survival rates which are significantly higher than achieved by antibiotic treatment per se.

When should we discontinue antiarrhythmic therapy for atrial fibrillation after coronary artery bypass grafting? A prospective randomized study.

BACKGROUND: New-onset atrial fibrillation after coronary artery bypass grafting is common. Medical therapy includes various antiarrhythmic drugs to control heart rate and restore sinus rhythm. The purpose of this study was to determine the duration of antiarrhythmic therapy after discharge from the hospital. METHODS: One hundred twenty-nine patients in whom new atrial fibrillation after coronary artery bypass grafting developed and successfully reverted to sinus rhythm were prospectively randomized at dismissal to receive antiarrhythmic therapy for 1 week (group A; n = 44), 3 weeks (group B; n = 42), or 6 weeks (group C; n = 43). Patients were followed up for an additional 4 weeks after discontinuation of antiarrhythmic therapy for detection of recurrent atrial fibrillation. RESULTS: The incidence of new atrial fibrillation during the study period was 21.2% (256/1206). Among the 129 patients who consented to the study, conversion to sinus rhythm was accomplished with the following medications: amiodarone (group A, 82%; group B, 93%; group C, 88%; P = .29), digoxin (group A, 16%; group B, 7%; group C, 7%; P = .29), beta-blockers (group A, 27%; group B, 19%; group C, 14%; P = .30), calcium channel blockers (group A, 2%; group B, 2%; group C, 0%; P = .60), quinidine (group A, 2%; group B, 2%; group C, 7%; P = .44), and procainamide (group A, 4.5%; group B, 2%; group C, 0%; P = .37). Follow-up was completed in 128 patients (99.2%). There was no significant difference in the recurrence of atrial fibrillation among groups (0%, 2%, and 0% for groups A, B, and C, respectively). CONCLUSIONS: Patients with new atrial fibrillation after coronary artery bypass grafting, converted to normal sinus rhythm before hospital discharge, have a benign course. Antiarrhythmic therapy as short as 1 week may be appropriate in these patients.

The surgical approach to infective endocarditis: 10 year experience.

BACKGROUND: About 40% of patients with infective endocarditis will require surgical treatment. The guidelines for such treatment were formulated by the American College of Cardiology and American Heart Association in 1998. OBJECTIVES: To examine our experience with surgical treatment of infective endocarditis in light of these guidelines. METHODS: Surgery was performed in 59 patients with infective endocarditis between 1990 and 1999. The patients' mean age was 48 years (range 13-80). The indications for surgery were hemodynamic instability, uncontrolled infection, and peripheral embolic events. The surgical treatment was based on elimination of infection foci and correction of the hemodynamic derangement. These objectives were met with valve replacement in the majority of patients. Whenever conservative surgery was possible, resection of vegetation and subsequent valve repair were performed and the native valve was preserved. RESULTS: Six patients (10%) died perioperatively from overwhelming sepsis (n = 3), low cardiac output (n = 2) and multiogran failure (n = 1). The mean hospital stay was 15.6 days. Of 59 patients, 47 (80%) underwent valve replacement and in 11 (19%) the surgical treatment was based on valve repair. After 1 year of follow-up there was no re-infection. CONCLUSION: The new guidelines for surgical treatment of infective endocarditis allow better selection of patients and timing of surgery for this aggressive disease, which consequently decreases the mortality rate. Valve repair is feasible and is preferred whenever possible. According to the new guidelines, patients with neurologic deficit in our series would not have been operated upon, potentially decreasing the operative mortality to 7%.

Cardiac surgery in octogenarians--a better prognosis in coronary artery disease.

BACKGROUND: Cardiac surgery is being performed with increasing frequency in patients aged 80 years and older. OBJECTIVES: To examine the long and short-term results of surgery in this age group. METHODS: We retrospectively investigated 202 consecutive patients aged 80 years or older who underwent cardiac surgery between 1991 and 1999, Ninety-six operations (48%) were urgent. RESULTS: The study group comprised 140 men (69%) and 62 women (31%) with a mean age of 82.1 years (range 80-89). Preoperatively, 120 patients (59%) had unstable angina, 37 (18%) had left main coronary artery disease, 22 (11%) had renal failure, 17 (8.5%) had a history of stroke and 13 (6.5%) had previous cardiac surgery. Hospital mortality for the whole group was 7.4%. Postoperative complications included: re-exploration for bleeding in 15 (7.4%), stroke in 8 (4%), sternal wound infection in 3 (1.5%), low cardiac output in 17 (8.4%), new Q wave myocardial infarction in 5 (2.5%), renal failure in 17 (8.5%), and atrial fibrillation in 71 (35%). The actuarial survival for patients discharged from the hospital was 66% at 5 years and 46% at 8 years. The type of surgical procedure was significantly associated with increased early mortality (coronary artery bypass grafting only in 2.9%, CABG + valve in 16.1%, valve only in 16.7%; P = 0.01). Significant predictors (P < 0.05) for late mortality included type of surgical procedure, congestive heart failure, and postoperative low cardiac output. CONCLUSIONS: When appropriately applied in selected octogenarians, cardiac surgery can be performed with acceptable mortality and good long-term results.

Incidental finding of myeloproliferative disorders during sternotomy.

We report 2 cases of myeloproliferative disorders discovered incidentally at the time of routine coronary bypass surgery. Suspicion of abnormal bone marrow tissue upon performing sternotomy and subsequent sampling for frozen section made the diagnosis. The surgical plan was changed, and partial revascularization without cardiopulmonary bypass was performed.