Cardiac morphofunctional characteristics of transgenic rats with overexpression of the bradykinin B1 receptor in the endothelium.

Our aim was to evaluate whether endothelial overexpressing of the bradykinin B1 receptor could be associated with altered left ventricular and myocardial performance. Echocardiography and hemodynamic were employed to assess left ventricular morphology and function in Sprague Dawley transgenic rats overexpressing the endothelial bradykinin B1 receptor (Tie2B1 rats). The myocardial inotropism was evaluated on papillary muscles contracting in vitro. In Tie2B1 animals, an enlarged left ventricular cavity and lower fractional shortening coupled with a lower rate of pressure change values indicated depressed left ventricular performance. Papillary muscle mechanics revealed that both Tie2B1 and wild-type rat groups had the same contractile capacities under basal conditions; however, in transgenic animals, there was accentuated inotropism due to post-pause potentiation. Following treatment with the Arg(9)-BK agonist, Tie2B1 papillary muscles displayed a reduction in myocardial inotropism. Endothelial B1 receptor overexpression has expanded the LV cavity and worsened its function. There was an exacerbated response of papillary muscle in vitro to a prolonged resting pause, and the use of a B1 receptor agonist impairs myocardial inotropism.

Repair of traumatic rupture of the aortic valve.

Traumatic aortic valve rupture is a rare complication of nonpenetrating cardiac injury and can be caused by a tear or avulsion of the valve. The most common method of treatment has been valve replacement, although valve repair has been successful in a few cases of cusp tear or detachment. We report a case of aortic valve commissural avulsion in which a reparative technique was applied and the natural valve was preserved.

Giant left atrium as cause of left pulmonary artery obstruction.

A case of a giant left atrium with compression of the left pulmonary artery and left main bronchus is described. The surgical approach was through a left thoracotomy, and the correction included mitral valve replacement, reduction atrioplasty, and dissection and release of the left pulmonary artery.

Atrial blood cyst: a rare finding.

Blood cysts of the heart, benign cardiovascular tumors, are extremely rare in adults. Our literature search found fewer than 20 such cases that have been reported in the past 30 years, all of which involved either the cardiac valves or the left ventricle. This case report describes a 72-year-old man with a right atrial tumor that was found to be a simple blood cyst.

Replacement of the descending thoracic aorta with intraluminal ring graft.

Renal failure and paraplegia are major complications of operations on the descending thoracic aorta. To minimize cross-clamp time and reduce the incidence of such complications, we have used an intraluminal ring graft to reestablish aortic continuity in patients with descending thoracic aortic lesions. From March 1978 to December 1986, we used this technique alone in 28 patients. There were 4 patients with traumatic aortic disruptions, 4 with dissections, 4 with expanding aneurysms, 2 with ruptured aneurysms, 1 with Marfan's syndrome, and 13 with atherosclerotic aneurysms that were repaired electively. The cross-clamp times ranged from 4 to 28 minutes. There were three early postoperative deaths (within 30 days) and one late postoperative death in the follow-up period (mean, 28.2 months). Ring dislodgement occurred only once, in the first patient in this series. There were no instances of postoperative renal failure or paraplegia. We conclude that the use of an intraluminal ring graft greatly reduces the aortic cross-clamp time and is a safe and effective technique.

Hypertrophy of nodules of Arantius and aortic insufficiency: pathophysiology and repair.

Aortic insufficiency (AI) due to fibrosis and thickening of the nodules of Arantius in the otherwise normal aortic valve was found in 11 adults (age range, 41 to 65 years) between 1976 and 1988. Nine had concomitant mitral stenosis; 2 had coronary artery disease. In 6 patients AI was graded 3+ or greater; in 5 it was less than 3+. Correction of AI and restoration of cuspid flexibility and apposition by shaving the hypertrophied nodules was accomplished in all, with postrepair AI graded as 1+ or less. There was one hospital death, a patient who had prior mitral operation. Mean follow-up was 68 +/- 56 months. Only 1 patient had late (6 years) recurrent serious (3+) AI. Nine continued to have 1+ or less AI, based on echocardiography or catheterization (n = 6) or on physical examination performed at a mean of 74 months. We conclude that thickening of the nodules of Arantius may cause AI. Long-term correction can be accomplished by sculpturing of the involved cusps.

Lunular hypertrophy and aortic valve disease.

Cuspid malcoaptation secondary to abnormal hypertrophy in combination with stiffening involving the line of apposition (lunular hypertrophy) has not been recognized as a cause of aortic valve dysfunction. This entity was found in 50 adults (mean age, 62 years). Thirty-three had pure aortic valve insufficiency (> or = 3+, n = 13; < 3+, n = 20), 13 had mixed aortic valve insufficiency and stenosis (> or = 3+, n = 2; < 3+, n = 11), and 4 had pure aortic valve stenosis. Forty-one had a history of rheumatic heart disease and advanced mitral valve disease, and 7 had coronary artery disease. All underwent shaving of the hypertrophic protuberances, which in 26 patients constituted the entire aortic valve repair. In the remaining 24 patients, aortic valve repair included one or more additional procedures; there were 15 commissurotomies, 12 debridements of calcium deposits from the base of the cusps, and 5 cusp resuspensions. Concomitant mitral valve repair was performed in 26 patients, mitral valve replacement in 15, tricuspid valve repair in 11, coronary artery bypass grafting in 7, and repair of an ascending aortic aneurysm in 2. In 2 patients, the attempt to repair the aortic valve was unsuccessful, necessitating valve replacement. There were 5 operative deaths (10%), but none were related to aortic valve repair. Forty-three patients entered follow-up (mean, 56 +/- 57 months). Three patients (7%) suffered late recurrent aortic valve insufficiency (at 6, 48, and 72 months). The remaining 40 patients (93%) had trivial or no recurrent aortic valve dysfunction. The 6-year actuarial freedom from aortic valve-related problems was 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

New technique for infusion of cardioplegic solution in aortic valve incompetence.

Direct coronary cannulation for induction of cardioplegia in patients with aortic valve incompetence may result in ostial stenosis. In order to circumvent this problem, a technique by which the valve was made competent by suturing the cusps together has been recently applied. Thus, an effective aortic cardioplegic infusion could be accomplished.

The choice of anticoagulation in pediatric patients with the St. Jude Medical valve prostheses.

Between February 1982 and January 1984 27 St. Jude Medical cardiac valve prostheses were implanted in 24 children ranging in age from 5 to 20 years (mean 12.38 years). There were 10 isolated aortic valve replacements, 14 isolated mitral valve replacements and one triple valve replacement (aortic, mitral and tricuspid). There was one operative and four late deaths. All patients were maintained on Aspirin and Dipyridamole from the early postoperative period. There were six documented thromboembolic events occurring in five patients. There were 0.68 thromboembolic events per patient year in the aortic valve group and 0.19 events in the mitral valve group. Because of the significant incidence of thromboembolic events in our patients, we now recommend universal anticoagulation with Coumadin in all pediatric age patients in whom the St. Jude Medical prosthesis is implanted.

An improved technique for venous drainage and right heart decompression.

Venous return for cardiopulmonary bypass is successfully achieved using of two stage cavoatrial cannula. Right heart decompression is facilitated and drainage optimized by the use of a caval occluding clamp which stabilizes the cannula. This technique is described.

Review of Salmonella mycotic aneurysms of the thoracic aorta.

Transient bacteremia leading to hematogenous infection of atherosclerotic vessels is the most common cause of mycotic aneurysms. Salmonella species, which are especially potent pathogens, often are the infecting organisms. A high index of suspicion is the cornerstone of diagnosis. Patients with salmonella cultured from the sputum, blood, or urine without adequate explanation must be suspected of intravascular infection. Surgical intervention with adjuvant ampicillin therapy should be expediently initiated after diagnosis. Provided no gross infection exists and prompt debridement and drainage are obtained, an "in situ" interposition graft is adequate. A ring graft has the advantage of allowing a shorter cross clamp time and eliminates the risks inherent in contaminated anastomotic suture lines. Prolonged, possibly life-long, antibiotic therapy offers the best prognosis for this disease after surgical repair.

Ebstein's anomaly: unusual presentation and surgical repair.

Ebstein's anomaly is the most significant congenital anomaly involving the tricuspid valve. This lesion may present in a simple form or may be complicated by other lesions. Patients with this anomaly may vary from mildly symptomatic to severely debilitated. The role of surgical treatment is not uniformly agreed upon, and the optimal procedure for correction or palliation is not clearly defined. Because of the wide spectrum of morphologic abnormalities which may be present in Ebstein's anomaly, no one particular operation may always be satisfactory. We and other groups continue to search for optimal procedures and feel strongly that individualization must be carried out to optimize the result in each patient. We encountered a patient with Ebstein's anomaly in an almost atretic tricuspid valve. In addition, there was severe right ventricular outflow tract obstruction and pulmonary valve stenosis. In this patient the "Fontan Principle" was successfully applied in his management.

Intravenous insulin infusion therapies for postoperative coronary artery bypass graft patients.

BACKGROUND: Hyperglycemia is very common in postoperative coronary artery bypass graft patients. Although sliding scale insulin therapy is often used, there is no standard of care for the management of hyperglycemia. METHODS: Different intravenous insulin therapies were used in three consecutive sets of hyperglycemic postoperative coronary artery bypass graft patients. The first method was a sliding scale intravenous insulin regimen beginning with four units/hr, and increasing by four units/hr each hourly bedside arterial whole blood glucose measurement greater than 250 mg/dL (13.9 mmol/L) (n = 58). The second and third methods were constant insulin infusions at a rate of eight units (n = 60) and 20 units/hr (n = 51) respectively. Insulin infusions were reduced to two units/hr when the glucose concentration decreased to 150-250 mg/dL (8.3-13.9 mmol/L), and was stopped when it fell below 150 mg/dL (8.3 mmol/L). RESULTS: Thirty percent of patients undergoing coronary artery bypass grafting had a diagnosis of diabetes mellitus. Forty-eight percent of all patients had a glucose value greater than 250 mg/dL (13.9 mmol/L) within the first 24 hours postoperatively. The three intravenous insulin infusion regimens produced similar control of arterial whole blood glucose concentrations. Patients with high initial glucose concentrations (greater than 400 mg/dL) (22.2 mmol/L) required intravenous insulin therapy for ten or more hours before attaining the target range of 151-250 mg/dL (8.3-13.9 mmol/L). CONCLUSIONS: Constant-rate intravenous insulin therapy is effective in lowering arterial whole blood glucose concentrations in postoperative coronary artery bypass graft patients. Initiation of intravenous insulin therapy at lower glucose values reduces the time necessary for the infusion.

Hemodynamic and thermoregulatory effects of xylazine-ketamine mixture persist even after the anesthetic stage in rats / Efeitos hemodinâmicos e termorregulatórios da mistura cetamina-xilasina persistem mesmo após o período anestésico em ratos

The xylazine-ketamine mixture (KX) is an anesthetic approach commonly administered to assess cardiovascular function in rodents. This study aimed to examine if the cardiovascular and thermoregulatory effects of KX could persist after the anesthetic state ceased in rats. Male Wistar rats were anesthetized with K (50mg/kg) X (10mg/kg) through the intra-peritoneal route. Hemodynamic and thermoregulatory repercussions were evaluated in animals in awake state, during an anesthetic depth and after complete recovery of anesthetized state. KX was efficient to significantly induce deep anesthesia in all rats after 10min. A complete recovery of anesthetized state was observed only after 210min. Compared with preanesthetic state and control animals that received no drug, KX induced a significant reduction of systolic and diastolic blood pressure at 10min. Hypotension was more prominent at 150min. The heart rate was also significantly reduced after 10 min of KX and the highest magnitude of bradycardia was observed at 30min. In addition, rectal temperature was markedly decreased at 30min of KX and the higher reduction occurred at 150min. The hemodynamic and thermoregulatory effects of KX were maintained even after complete anesthetic recovery.

Objetivou-se com este estudo avaliar a persistência dos efeitos cardiovasculares e termorregulatórios da associação cetamina e xilasina (CX) mesmo após o período anestésico em ratos. Ratos Wistar machos foram anestesiados com cetamina 50mg/kg e xilasina 10mg/kg, por via intra-peritoneal. As repercussões hemodinâmica e termorregulatória foram avaliadas com os animais acordados, durante o período anestésico e após recuperação completa da anestesia. A CX foi eficiente em induzir significante regime anestésico em todos os ratos após 10min. A recuperação completa do estado de anestesia foi observada somente após 210min. Comparado com o estado pré-anestésico e com animais controles, que não receberam anestesia, a CX induziu significativa redução das pressões sistólica e diastólica aos 10min. A hipotensão foi mais evidente aos 150min após CX. A frequência cardíaca também foi significativamente reduzida com 10min de CX e a bradicardia foi mais acentuada aos 30min. A temperatura retal foi reduzida aos 30min, sendo mais acentuada após 150min de anestesia. Os efeitos hemodinâmicos e termorregulatórios da CX persistem mesmo após completa recuperação anestésica.

Comparative efficacy of cimetidine, famotidine, ranitidine, and mylanta in postoperative stress ulcers. Gastric pH control and ulcer prevention in patients undergoing coronary artery bypass graft surgery.

To determine the comparative efficacy of several histamine (H2)-receptor antagonists (cimetidine, famotidine, and ranitidine) and the antacid Mylanta-II (Stuart Pharmaceuticals, Wilmington, DE) in gastric pH control and the prevention of postoperative stress ulceration, a prospective, randomized study was performed in a homogeneous population of patients with elective coronary artery bypass. None of the 57 patients in the study population had a documented history of ulcer disease. There were four treatment groups, each with similar demographics (age and sex). Cimetidine-treated group consisted of 15, famotidine-treated group of 18, ranitidine-treated group of 19, and antacid-treated group of 5 patients. There was no hemodynamically significant postoperative gastrointestinal bleeding in any of the patients. When the agents were compared for efficacy of gastric pH control, statistically better pH control was found in the famotidine- and ranitidine-treated groups (P less than 0.003) than in the cimetidine-treated group (pH less than or equal to 4.0) during the 20-hour observation period. Side effects (hematologic and neurological) were noted only in the cimetidine-treated group. The results of this study indicate that in patients in postoperative intensive care, better gastric pH control, and thus prevention of gastric stress ulcers, is achieved with either famotidine or ranitidine rather than cimetidine or antacid.