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Biomedical subjects

T A English

Publications and source records attributed to T A English.

At least 37 records · Page 2Linked to original sources
PubMed1988

Percutaneous coronary angioplasty in a cardiac transplant recipient.

Two years after an orthotopic cardiac transplant a 28 year old man was found to have clinically significant stenosis of the right coronary artery at routine coronary angiography. This lesion was accompanied by a perfusion defect on exercise thallium scintigraphy. Percutaneous transluminal coronary angioplasty of the lesion improved the angiographic appearance of the stenosis and reduced the exercise thallium perfusion defect.

Adult↗
PubMed1988

Cardiac surgery for patients aged 65 years and older: a long term survival analysis.

Between January 1973 and December 1984, 562 patients aged greater than or equal to 65 had cardiac surgery at Papworth Hospital. Most had mitral or aortic valve replacements (coronary artery bypass grafting was not introduced for this age group at Papworth until 1977). The overall operative mortality, defined as death within thirty days or death before leaving hospital, was 7.3%. There were no early deaths in patients undergoing coronary artery bypass grafting surgery. Questionnaires sent to general practitioners in East Anglia traced 86.0% of the patients who survived to leave hospital. The longer term survival rates for all patients were 88.0%. (95% confidence interval (CI) 85 to 91) at one year and 74.4% (95% CI 69 to 79) at five years. The rates for those patients who survived the initial few months were 96.3% (95% CI 94 to 98) at one year and 81.5% (95% CI 77 to 86) at five years and these rates were no different from those in the general population aged greater than or equal to 65.

Aged↗
PubMed1988

Cytomegalovirus infections in heart and heart and lung transplant recipients.

Of the first 166 heart and 15 heart and lung transplant recipients at Papworth Hospital, Cambridge, who survived for more than one month after transplantation, 162 were investigated for cytomegalovirus (CMV) infection by serological methods. Altogether, 73 (45%) developed CMV infection after transplantation: 30 (18.5%) had acquired primary infection and 43 (26.5%) reactivation or reinfection. Six patients died of primary infection, probably acquired from the donor organ. Recipients negative for CMV antibody who received an organ from an antibody positive donor had the most severe disease. Heart and lung transplant recipients experienced more severe primary CMV infection than those in whom the heart alone was transplanted. The most sensitive and rapid serological method was a mu-capture enzyme linked immunosorbent assay (ELISA) for detecting CMV specific IgM, the amount of which was often of prognostic value and influenced the management of patients.

Adolescent↗
PubMed1988

Selection and procurement of combined heart and lung grafts for transplantation.

Between April 1984 and July 1986, 14 patients underwent heart-lung transplantation at Papworth Hospital, Cambridge, England. The donors for the first five operations were brought to our hospital and the organs removed in the operating theater adjacent to that in which the recipients were prepared. Subsequently, organs have been procured from distant centers. The total ischemic time ranged from 48 to 51 minutes (mean 49.6) for the near procurement group and from 70 to 186 minutes (mean 123.6) for the distant procurement group. Our method of preservation consists of cold cardioplegic arrest of the heart with St. Thomas' Hospital solution followed by a single cold (4 degrees C) pulmonary artery flush with a solution containing 500 ml donors blood, 700 ml Ringer's solution, 200 ml 20% salt-poor albumin, 100 ml 20% mannitol, 20 micrograms prostacyclin, and 10,000 units heparin. Function of the lungs after implantation was assessed by measuring the alveolar-arterial oxygen gradient. The median alveolar-arterial oxygen gradient measured shortly after discontinuation of bypass (point 1), just before extubation (point 2), and at 1 week (point 3) were 96.0, 62.3, and 18.8 mm Hg, respectively, for the near procurement group and 91.5, 60.0, and 11.3 mm Hg, respectively, for the distant procurement group. Comparison of the two groups at the three measurement points by the nonparametric Wilcoxon test showed no significant difference (p = 0.44, 0.52, and 0.11, respectively). The two groups showed significant decline of the alveolar arterial oxygen gradient differences over the first week (p = 0.004, nonparametric Friedman test). We conclude that our method of preservation provides a satisfactory function after implantation. The alveolar-arterial oxygen gradient differences were high immediately after implantation but decreased significantly afterward.

Adolescent↗
PubMed1988

Three solutions for preservation of the rabbit heart at 0 degree C. A comparison with phosphorus-31 nuclear magnetic resonance spectroscopy.

Phosphorus-31 nuclear magnetic resonance has been used to measure changes in tissue adenosine triphosphate and pH that occur during hypothermic preservation of rabbit hearts. Three potential preservation solutions were studied: the St. Thomas' Hospital no. 1 cardioplegic solution, Bretschneider's HTP solution, and a solution originated in our laboratory, CP5, which we have previously studied in the rabbit heart with functional assessment by Langendorff perfusion. After being flushed with one of these solutions, each heart was stored at 0 degrees C for 12 hours, during which time it was subjected to repeated phosphorus-31 nuclear magnetic resonance scans. It was shown that adenosine triphosphate levels decayed more slowly with CP5 than with either of the other solutions or in the control experiments. Adenosine triphosphate decay was also slower with Bretschneider's HTP than with St. Thomas' Hospital solution, but pH was somewhat better maintained with Bretschneider's HTP than with either other solution or in the control hearts, although the pH did not decrease drastically in any group. CP5 was designed to prevent cell swelling and to reduce the uptake of calcium during storage, for which reasons it contains 30 mmol/L glucose and 0.1 mmol/L calcium. The potassium content is somewhat higher and the sodium and magnesium content somewhat lower than in St. Thomas' Hospital solution, with the objective of stabilizing intracellular concentrations of these ions during storage.

Adenosine Triphosphate↗
PubMed1987

Analysis of responses to a selective phosphodiesterase III inhibitor, SK&F 94120, on isolated myocardium, including human ventricular myocardium from "end-stage" failure patients.

The actions of SK&F 94120, a selective phosphodiesterase (PDE III) inhibitor, have been characterised on human ventricular myocardium obtained from heart failure patients. Some actions have been compared directly with those of the drug on guinea pig and cat ventricular myocardium. SK&F 94120 caused positive inotropic responses in preparations from all three species. In the human preparations, there was no evidence of differential activity in ventricles obtained from patients with heart failure associated with ischaemic heart disease, congestive cardiomyopathy, or mitral valve disease. The mechanism of positive inotropic activity of SK&F 94120 demonstrated characteristics of PDE III inhibition--e.g., potentiation of isoprenaline responses and reversal by carbachol. In addition, in human tissue a highly significant correlation between positive inotropic activity and increases in intracellular cAMP was demonstrated. Electrophysiological studies in human and guinea pig myocardium demonstrated that SK&F 94120 enhanced the second inward Ca2+ current over the same concentration range as that needed for positive inotropic activity. This was demonstrated in preparations incubated in Krebs bicarbonate solution and, more clearly, in solutions with raised K+ concentration. The data described in this report establish that inhibition of PDE III is an effective positive inotropic mechanism in human ventricular myocardium. Comparison of the responses in human, guinea pig, and cat myocardium shows clear similarities of responses with only small quantitative differences.

Animals↗
PubMed1987

Heart and heart-lung transplantation Papworth Hospital 1979 to 1987.

The quality of life for those who survive the first 3 months after transplantation is generally good. The duration of hospital stay and the cost of transplantation per patient have been reduced during the last 3 years. Cardiologists are coming to appreciate the therapeutic potential of both heart and heart-lung transplantation and one of the chief logistic problems faced is that of increasing the provision of transplant services to match the increasing demand. Ultimately this will be donor-limited but at present in the United Kingdom the main limitation to the expansion of services is restriction of funding and resources. (The allocation for heart transplantation from the DHSS for the financial year 1987/88 is 4.3 million pounds). The broad principles of management of heart and heart-lung recipients have been established. Further improvement in medium-term results can be anticipated as a result of reducing CsA-induced nephrotoxicity and hypertension as a result of triple therapy and adjusting the components of that therapy to the individual needs of particular patients. Heart transplantation has now taken its place as an established therapy for life-threatening heart disease. Heart-lung transplantation is still going through its developmental phase with acceptable short-term results, but with much to learn in the mid- and long-term following transplantation.

Adolescent↗
PubMed1987

Biopsy assessment of fifty hearts during transplantation.

The aim of the study was to evaluate myocardial protection during the transportation of human donor hearts stored at 4 degrees C in crystalloid cardioplegic solution. Biopsies were performed on 50 donor hearts before excision and at four subsequent time intervals during transplantation. Quantitative birefringence measurements on cryostat sections of the left ventricular biopsy specimens were used to assess myocardial function. Fifteen donor hearts had poor birefringence assessments before excision, and 67% received inotropic support after implantation; 22 deteriorated during transportation, and 50% received inotropic support; 13 were unchanged throughout the procedure, and none required inotropic support. This study demonstrates the need for improved protection of donor hearts during transportation and recommends the use of rigorous criteria in the selection of these hearts.

Adolescent↗
PubMed1986

Impromidine is a partial histamine H2-receptor agonist on human ventricular myocardium.

The inotropic effects of impromidine have been studied and compared with those of histamine on human isolated left ventricular preparations stimulated at 1 Hz. Both drugs caused concentration-related increases in force of contraction and were of similar potency, although the maximum response to impromidine was markedly and significantly less than that to histamine. The positive inotropic responses of impromidine were inhibited by cimetidine 1 X 10(-5) M, consistent with histamine H2-receptor involvement. Impromidine 1 X 10(-4) M inhibited maximal responses to histamine to a level equal to the maximal impromidine response; however, impromidine did not inhibit responses to isoprenaline. Positive inotropic activity and inhibition of maximal responses to histamine occurred over a similar impromidine concentration-range. Impromidine displaced histamine concentration-response curves to the right, whereas mepyramine had no effect on responses to histamine. It is concluded that impromidine has positive inotropic activity on the human ventricle, that the response is mediated via histamine H2-receptors, and that impromidine is a partial agonist compared with histamine.

Female↗
PubMed1986

Transvenous lung biopsy in the pig.

At present there is no satisfactory technique for repeated lung biopsy in recipients of heart-lung transplants. A new technique for lung biopsy, which might be adopted for this purpose, has been developed. A Teflon sheath is inserted through the jugular vein into the pulmonary artery with the aid of a balloon catheter. A flexible biopsy forceps is then introduced through the sheath into the pulmonary arterial tree and advanced into the periphery of the lung, where biopsy samples are taken. The procedure was attempted in 14 pigs. Initially crocodile jaw (two pigs) and fenestrated cups forceps (five pigs), which are currently in use for transbronchial lung biopsy, were used. Subsequently the biopsy forceps was modified and the jaws were replaced by a cutting needle mechanism (six pigs). Out of the 13 animals in which the procedure was technically possible, lung parenchyma was obtained from nine and pulmonary arterial wall from 11. One animal died shortly after the procedure. The cause of death could not be determined with certainty at postmortem examination. There was, however, a small tear on the surface of the lung, which could have produced a tension pneumothorax. The other 12 animals recovered from the procedure. They were killed 24 hours later and postmortem examination was carried out. One animal in which the crocodile jaw forceps had been used had a haematoma in the lower lobe (3 X 3 X 4 cm) and 100 ml of blood in the pleural cavity. In the other 11 animals, in which the fenestrated cups or the cutting needle forceps had been used, the intrapulmonary haematomas were 1-2 cm in diameter and the pleural surface was intact. It is concluded therefore that transvenous lung biopsy is feasible and that this procedure might find an application in monitoring rejection in recipients of heart-lung transplants.

Animals↗
PubMed1985

Does left ventricular aneurysmectomy improve ventricular function in patients undergoing coronary bypass surgery?

Fourteen consecutive patients undergoing left ventricular aneurysmectomy and coronary artery bypass grafting were studied by multiple gated ventricular scintigraphy at rest and during exercise before and at six weeks and six months after surgery. All had congestive heart failure and 12 angina pectoris. Before operation left ventricular ejection fraction fell significantly with exercise, as did the regional wall motion score. Six weeks after surgery all surviving patients were free of angina, with an improvement in functional class; the total exercise workload improved significantly, but resting left ventricular ejection fraction was unchanged; the regional wall motion score improved in both the anterior and left anterior oblique projections, although extensive areas of abnormal contraction persisted. Exercise left ventricular ejection fraction improved significantly after operation at six weeks, and previous exercise induced abnormalities of regional contraction were abolished. Six months after operation angina pectoris had recurred in one patient, but there was no further change in ventricular function in the remainder. Although resting ejection fraction is not improved, symptoms, exercise workload, and exercise ventricular function can be improved by aneurysmectomy and coronary artery bypass grafting, but the respective contribution of these two procedures remains uncertain.

Adult↗