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Biomedical subjects

A Kenny

Publications and source records attributed to A Kenny.

50 records · Page 3Linked to original sources
PubMed1992

Sudden cardiac death in athletes.

Sudden death in athletes is a rare but tragic occurrence. Congenital cardiovascular abnormalities, usually asymptomatic and often undiagnosed during life, are the main causes in young athletes. Hypertrophic cardiomyopathy and congenital coronary anomalies are the most commonly occurring disorders. Idiopathic concentric left ventricular hypertrophy (non-physiological), arrhythmogenic right ventricular dysplasia and Marfan's syndrome with aortic rupture have also been implicated. Rarer causes include mitral valve prolapse and myocarditis. Coronary atherosclerosis is the major cause in older, and occasionally in younger athletes. Those involved in the medical care of athletes should be aware of the potential causes of sudden death in these groups. Symptomatic athletes should be fully investigated. Screening programmes are probably not justified on a cost effective basis.

Adult↗
PubMed1992

Conservative surgery of the mitral valve: a report of the first 100 cases from one unit and one surgeon.

OBJECTIVE: To report the first 100 mitral valve repairs performed in a unit with an aggressive approach to conservative mitral valve surgery. DESIGN: Case notes were reviewed retrospectively and patients invited for clinical examination and cross sectional and Doppler echocardiography. SETTING: Tertiary cardiothoracic referral centre. PATIENTS: Between December 1985 and April 1991 mitral valve repair was carried out on 100 patients (66 males). Patients with pure mitral stenosis were excluded. Sixty seven had degenerative and 15 rheumatic mitral valve disease. Median age was 66 (range 12 to 79) years, with an interquartile range of 59 to 71 years. INTERVENTIONS: Operative procedures included annuloplasty ring in 97, resection of the posterior leaflet in 67, resection of endocarditic portion of posterior leaflet in four, commissurotomy in six, and correction of anterior leaflet abnormalities in seven. Thirty nine concomitant cardiac procedures were performed in 32 patients. Six operations were emergencies, and three of these required concomitant procedures. MAIN OUTCOME MEASURES: Mortality, operative failure rate, patients' functional state and degree of residual mitral regurgitation, incidence of thromboembolism, and endocarditis. RESULTS: Follow up ranged from one to 59 months, median 14 months, and an interquartile range of four to 23.5 months. Early mortality was 1%, late mortality 5%, and there was a 2% reoperation rate. Eighty four patients had moderate to severe mitral regurgitation preoperatively. At follow up mitral regurgitation was absent or mild in 78. Eighty six patients were in New York Heart Association (NYHA) class I-II at follow up compared with 80 in NYHA class III-IV preoperatively. There were no thromboembolic events. CONCLUSION: This study shows that satisfactory results can be obtained with mitral valve repair in a fairly elderly population with a high incidence of concomitant cardiac disorders. We suggest that these encouraging results will lead to earlier mitral valve repair in mitral regurgitation.

Adolescent↗
PubMed1992

Hemodynamic evaluation of the Monostrut and spherical disc Björk-Shiley aortic valve prosthesis with Doppler echocardiography.

A Doppler echocardiographic study was performed to assess whether the Monostrut model of the Björk-Shiley valve (Shiley, Inc., Irvine, Calif.) had an improved hemodynamic performance in comparison with the spherical disc model in the aortic position. Twenty retrospectively randomly selected patients were studied, 10 with each valve type. Within each valve type two sizes of valve were studied, 21 and 23 mm. The two groups were comparable with respect to age, postoperative time, fractional shortening, New York Heart Association functional class preoperatively, and body surface area. Pulsed and continuous wave Doppler measurements were recorded at rest. Continuous wave Doppler recordings were performed every 2 minutes after exercise with supine bicycle ergometry until 10 minutes after exercise. Peak and mean gradients across the aortic valve prostheses were estimated. Both groups achieved a significant and comparable rise in heart rate with exercise. The mean gradients +/- standard error of the mean at rest and 2 minutes after exercise were 19.7 +/- 1.9 mm Hg and 30.9 +/- 2.2 mm Hg, respectively in the spherical disc group compared with 14.9 +/- 1.1 mm Hg and 23.6 +/- 1.7 mm Hg in the Monostrut group (p < 0.05 and p < 0.025, respectively). Peak transvalvular gradient at rest was 30.7 +/- 2.7 mm Hg in the spherical group compared with 23.9 +/- 1.9 mm Hg in the Monostrut group (p < 0.05). We conclude that the Monostrut Björk-Shiley valve prosthesis has better hemodynamic performance than the spherical disc model in the aortic position.

Aortic Valve↗
PubMed1991

Histopathological validation of high frequency epicardial echocardiography of the coronary arteries in vitro.

The accuracy and reliability of measurement of coronary artery dimensions and detection of atherosclerotic lesions by high frequency epicardial echocardiography were compared with histopathological results. Ten pressure perfused human hearts were examined in vitro with a 10 MHz (Diasonics) transducer and a 7.5 MHz (Vingmed/Sonotron) transducer. There was close agreement between ultrasound and pathological measurements of coronary artery luminal diameter. Qualitative changes in wall structure such as diffuse wall thickening and calcification were readily identified; however, the resolution of the transducers was not high enough accurately to measure wall dimensions in normal coronary arteries. Coefficient of variation measurements for intra and inter observer variability (5.2% and 6.9% respectively) showed excellent reproducibility. The technique was accurate in identifying atherosclerotic lesions, imaging arteries distal to an occlusion, locating deeply sited arteries, and identifying complete obliteration of an artery. Intraoperative video playback and transducer miniaturisation may minimise problems caused by cardiac movement and restricted access. With these developments intraoperative assessment of coronary artery disease may become a real possibility.

Coronary Artery Disease↗
PubMed1986

Anomalies of Section 2 of the Homicide Act 1957.

Section 2 of the 1957 Homicide Act is indefensible: the concept of 'mental responsibility' is a hybrid which turns the psychiatrist witness either into a thirteenth juryman or a spare barrister. But reform does not lie along the lines suggested by the Butler Committee or the Criminal Law Revision Committee. The latter leaves the jury with insufficient guidance; the former returns to the bad eighteenth century policy of treating mental illness not as a factor in determining responsibility but as a status exempting from responsibility. The much criticised McNaughton rules provide a sounder basis for deciding where responsibility should be assigned in criminal cases.

Female↗
PubMed1984

The psychiatric expert in court.

The law about expert evidence is unsatisfactory: it gives scope for the expert to usurp the role of judge, jury and parliament; it brings the professions of the experts into disrepute; and it sets juries the impossible task of sorting pseudo sciences from genuine ones. The law should be reformed by changing statutes which force expert witnesses to testify beyond their science, by taking the provision of expert evidence out of the adversarial context, and by removing from the courts the decision whether a nascent discipline is or is not a science.

Criminal Law↗
PubMed1981

Pediatric surgical patients with severe anaerobic infection: report of 16 T-antigen positive cases and possible hazards of blood transfusion.

Red blood cells become polyagglutinable when the normally latent T-antigens of the red blood cell membrane are exposed. Unmasking of T-antigens results from removal of N-acetyl-neuraminic acid by neuraminidase, an enzyme commonly produced by a variety of bacteria. Red blood cells altered in this way are said to be T-activated. T-activated red blood cells can be agglutinated by anti-T, an antibody normally present in human serum, so that severe transfusion reactions may occur and have occurred, if T-antigen positive patients are transfused with normal whole blood or plasma. This can be avoided by transfusing only packed or washed red blood cells. From October 1978 to October 1980 we found T-activation in 16 pediatric surgical patients aged 3 days to 14 yr with severe anaerobic infections. This included patients with necrotizing enterocolitis, perforated appendicitis, megacolon, infected anal atresia and gas gangrene. The isolate neuraminidase-producing bacteria were Clostridium perfringens and Bacteroides fragilis. Clinical data of these 16 patients are briefly reviewed and the importance of T-antigen positivity for their management is discussed.

Adolescent↗
PubMed1980

Necrotising enterocolitis and neuraminidase-producing bacteria.

In 9 out of 26 newborns with necrotising enterocolitis (NEC) exposure of the Thomsen-cryptantigen (T-antigen), probably due to the action of circulating bacterial neuraminidase, was demonstrated on red blood cells. The serological titres seemed to correlate with the clinical course of the disease. Neuraminidase-producing clostridia were isolated in two of the patients. Reaction between the exposed T-antigen and anti-T-agglutinins, normally present in human blood, may lead to difficulties during blood transfusion. This potential transfusion hazard is best avoided by routine T-antigen-tests and by transfusion of packed or washed red blood cells to T-antigen-positive patients.

Antibody Specificity↗
PubMed1980

Hemolytic-uremic syndrome associated with neuraminidase-producing microorganisms: treatment by exchange transfusion.

In two infants with pneumonia, Coombs test positive hemolytic anemia and hemolytic uremic syndrome (HUS), exposure of the Thomsen cryptantigen, probably due to the action of circulating neuraminidase, was demonstrated. Reaction between the exposed T-antigen and anti-T agglutinin, normally present in human blood, can lead to difficulties in serological testing and during blood transfusion. The place of exchange transfusions using washed RBC or heparinized whole blood in the management of this subgroup of HUS is discussed.

Antigens↗
PubMedDate not supplied

Intraoperative epicardial echocardiography with a miniature high-frequency transducer: imaging techniques and scanning planes.

Intraoperative Doppler echocardiography has the potential to provide anatomic and functional information but is hindered by the large size of standard transducers. We describe new scanning planes accessible through the application of a new 5 MHz miniature transducer with imaging, Doppler, and color-flow capability. Epicardial echocardiography was performed in 15 adults undergoing elective coronary artery bypass grafting. Standard parasternal equivalent, subcostal equivalent, aortopulmonary sulcus and aortosuperior vena caval views were obtained. Previously unobtainable apical four-chamber, five-chamber, and long-axis views were possible by positioning the transducer at the apex. The transducer has a broad bandwidth, allowing high-quality imaging at different depths and could be maneuvered laterally, posteriorly, and over the aorta and pulmonary arteries to provide off-axis views. The proximal-mid coronary arteries were imaged on the beating heart with a standoff medium. Transducer miniaturization should expand the role of epicardial ultrasonography in the surgical management of heart disorders.

Adult↗