Valve prostheses have played an important part in the past two decades in the management of patients with valvular heart disease. However, many of the devices used in valve replacement have introduced new clinical problems. This paper deals with some of the problems associated with valve replacement, including one not previously emphasized--valve prosthesis-patient mismatch, which may cause obstruction to ventricular outflow and/or inflow.

The problem of valve prosthesis-patient mismatch.

The Sixth Conference on the "Standards of Laboratory Practice Series", sponsored by the National Academy of Clinical Biochemistry (NACB), was held on August 4-5, 1998, at the Annual Meeting of the American Association for Clinical Chemistry, in Chicago, IL. An expert committee was assembled to write recommendations on the use of cardiac markers in coronary artery diseases. The NACB Committee prepared a preliminary draft of the guidelines, made them available on the World Wide Web (www.nacb.org), and distributed them before the presentations. The recommendations were divided into four areas: the use of markers in the triage of patients with chest pain, acute coronary syndromes, clinical applications other than acute myocardial infarction and research, and assay platforms and markers of acute myocardial infarction. The recommendations were revised and subsequently re-presented in part at the "Biomarkers in Acute Cardiac Syndromes Conference", sponsored by the Jewish Hospital Heart and Lung Institute, Louisville KY, on October 16-17, 1998. This report lists each recommendation, its scientific justification, and a summary of discussions from conference participants and reviewers. Approximately 100 individuals responded to various versions of these recommendations via direct correspondences, telephone calls to Committee members, electronic mail correspondence to the Committee Chairman, or oral questions and comments raised during one of the two conference presentations. Some of the recommendations were changed to reflect the consensus opinion. In cases in which there was no consensus, the Committee included pertinent discussion without necessarily changing the original recommendations. At times, the Committee members felt that although a particular recommendation might not be the current standard of care today, they anticipate that it likely will be adopted in the near future.

http://grupoeclab.com.mx/Doctos/articulos/recommendations_for_the_use_of_cardiac_markers.pdf

National Academy of Clinical Biochemistry Standards of Laboratory Practice: Recommendations for the Use of Cardiac Markers in Coronary Artery Diseases

Fontan operation in five hundred consecutive patients: Factors influencing early and late outcome ☆ ☆☆ ★ ★★ ♢ ♢♢ ♦

https://journal.chestnet.org/article/S0012-3692(15)60797-8/pdf

Antithrombotic Therapy in Children

Background—Infection remains a serious complication after permanent pacemaker implantation. Antibiotic prophylaxis is frequently prescribed at the time of insertion to reduce its incidence, although results of well-designed, controlled studies are lacking. Methods and Results—We performed a meta-analysis of all available randomized trials to evaluate the effectiveness of antibiotic prophylaxis to reduce infection rates after permanent pacemaker implantation. Reports of trials were identified through a Medline, Embase, Current Contents, and an extensive bibliography search. Trials that met the following criteria were included: (1) prospective, randomized, controlled, open or blind trials; (2) patients assigned to a systemic antibiotic group or a control group; (3) end point events related to any infection after pacemaker implantation: wound infection, septicemia, pocket abscess, purulent secretion, right infective endocarditis, inflammatory signs, a positive culture, septic pulmonary embolism, or repeat op...

Antibiotic Prophylaxis for Permanent Pacemaker Implantation A Meta-Analysis

Right atrial-right ventricular anastomosis for correction of tricuspid atresia.

One hundred and one patients with aortic valve disease, aortic stenosis 29 patients, aortic insufficiency 29 patients and combined lesions in 43 patients, underwent valve replacement with the Bjork-Shiley tilting disc prosthesis. Early and late mortality rate 8% and 3% respectively. Six patients died in heart failure, 2 after a myocardial infarction, one due to cardiomyopathy, one of septicaemia and one due to carcinoma of the stomach. No thrombo-embolic complications were encountered.Fifty-seven of the patients were subjected to a follow-up study 6 to 8 months after surgery, including right and left heart catheterization. All these 57 patients were subjectively improved by the operation and 30/57 were considered to be in an excellent clinical condition.The heart volume in supine decreased on average 20% after operation. The exercise tolerance (Wmax) increased in 24/57 patients. There were marked decreases in left ventricular systolic and end diastolic pressures. Pulmonary arterial and right heart pressur...

Clinical and haemodynamic results of aortic valve replacement with the bjork-shiley tilting disc valve prosthesis

A pulse duplicator system, used for studying prosthetic heart valves, is described. It provides a pulsatile flow resembling that produced by the heart, and permits a quantitative estimation of fluid flow resistance, regurgitation and energy loss in the valves. A technique for visualization of flow pattern is presented. The hydrodynamic performance of five prosthetic aortic valves, Starr-Edwards, Smeloff-Cutter, Kay-Shiley, Wada-Cutter and Bjork-Shiley, were studied in the pulse duplicator and compared on the basis of their external (tissue) diameters. For a given tissue diameter, the Bjork-Shiley valve had the best performance, resulting in a significantly lower flow resistance and energy loss than in the other prostheses investigated. All valves had acceptably low degrees of regurgitation with the exception of the Wada-Cutter prosthesis (16 to 20% of stroke volume). Flow visualization demonstrated a more or less turbulent flow pattern in all the valves with the exception of the Bjork-Shiley valve. In thi...

Pulsatile flow Studies of Prosthetic Aortic Valves

Between 1971 and 1978 septicaemia was observed in 14 patients undergoing permanent pacemaker treatment. The causative microorganisms were: S aureus (9), S. epidermidis (3), alfa–haemolytic streptococci + P. morganii (1), enterococci (1). In 4 patients, a mural endocarditis of the right atrial wall surrounding the electrode was found at operation or autopsy. The interval between the preceding pacemaker operation and onset of septicaemia varied between 2 days and 23 months (median 2 months). In 5 patients, the last operation before septicaemia was performed because of local infection in the pacemaker pocket or along the electrode. A probable portal of entry was found in 11 patients. The electrode was the origin in 8, the pacemaker pocket in one, and a focus outside the pacemaker system in 2. Of the 6 patients treated with antibiotics alone, 3 were cured. 2 died and one is still on treatment. Eight patients underwent various surgical procedures in addition to the antibiotic treatment. In 4 the electrode was ...

Septicaemia and endocarditis--uncommon but serious complications in connection with permanent cardiac pacing.

To evaluate the effect of antibiotic prophylaxis in pacemaker surgery, 100 patients were randomly assigned to a prophylaxis group receiving cloxacillin or to a control group with no antibiotics. Cloxacillin was given intravenously (2 g) 2 hours before operation, followed by 1 g every 6 hours for 2 days and the same dose perorally for 8 more days postoperatively. Adequate plasma concentrations were obtained in all patients. The follow-up time was 1-43 months. The infection rate was 2% (1/50) in the prophylaxis group and 14% (7/50) in the control group (p less than 0.05). The interval from operation to manifest infection was 9-35 days. In the control group the causal microorganism was Staphylococcus aureus in two patients, Staphylococcus epidermidis in two and unknown in three patients. In the only patient with infection in the prophylaxis group, a methicillin-resistant S. epidermidis was isolated. Infection was initially localized to the pacemaker pocket in seven patients, but septicemia developed in one of them and endocarditis in another. In one patient septicemia appeared initially, without local signs of infection. This study suggests that cloxacillin prophylaxis is of value in routine pacemaker surgery.

Christian Olin

Papers

Right atrial-right ventricular anastomosis for correction of tricuspid atresia.

Clinical and haemodynamic results of aortic valve replacement with the bjork-shiley tilting disc valve prosthesis

Pulsatile flow Studies of Prosthetic Aortic Valves

Septicaemia and endocarditis--uncommon but serious complications in connection with permanent cardiac pacing.

Antibiotic prophylaxis in pacemaker surgery--a prospective study.