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Biomedical subjects

G C Shardey

Publications and source records attributed to G C Shardey.

7 recordsLinked to original sources

Developing performance indicators for cardiac surgery: a demonstration project in Victoria.

Six Victorian cardiac surgical units pooled data in order to undertake a demonstration project aimed at developing performance indicators to assess outcomes following cardiac surgery. The outcome of the project was an indicative report for the purpose of monitoring surgical performance indicators in a format suitable for: (i) the general public; (ii) the Victorian State Government; and (iii) the participating units and surgeons. Each participating cardiac surgical unit had an existing database used for recording information from each procedure. A request was made to each unit to extract a subset of data from all cases entered over the past 5 years. The proposed list of performance indicators included surgical mortality (within the period of admission for surgery), complication rates (including sternal infection, postoperative myocardial infarction, postoperative stroke, haemorrhage requiring return to theatre), and length of hospital stay. A model was developed from the data and used to provide risk-adjusted measures of hospital performance. Cases from five cardiac surgical units (n = 10 715) were included in the final analysis. A risk-adjusted model (including age, sex, diabetes, hypertension, smoking, procedure type, urgency of procedure) was developed for surgical mortality. Performance indicators for coronary artery bypass graft surgery, including mortality, sternal infection rate and length of hospital stay are presented. From the available data, performance indicators for cardiac surgery in Victorian hospitals compared favourably with international benchmarks. This project has demonstrated that prospective data collection using a standardised system could readily produce local risk-adjustment models for cardiac surgery to aid in developing appropriate performance indicators.

Journal Article↗

Clinicopathological correlates of cardiac myxomas: a 30-year experience.

Between 1961 and 1991, 23 patients (eight men and 15 women, with a mean age of 50 (range 25-72) years) with cardiac myxomas were managed at the Alfred Hospital, Prahran, Victoria, Australia. Symptoms of mitral valve obstruction were present in 13 patients and of systemic embolism in nine. In the patients, 21 myxomas were confined to the left atrium. In the other two patients, one myxoma was confined to the right atrium and the other was a dumb-bell-shaped biatrial myxoma. Most tumours were diagnosed with echocardiography. Removal was achieved via a median sternotomy and by entering the involved chamber. Those myxomas presenting with systemic embolism were always soft and friable, whereas those with obstructive symptoms were large and of variable consistency. There was one operative death early in the series. The 22 surviving patients have been assessed as functional class I of the New York Heart Association at follow-up, ranging from 2 months to 23 years (mean 9 years). There were no episodes of tumour recurrence. Excellent short, intermediate and long-term results can be achieved by excision of cardiac myxomas.

Adult↗

Early and late results of surgery for Wolff-Parkinson-White syndrome.

Surgical treatment for accessory atrioventricular connections was performed in 60 patients with Wolff-Parkinson-White syndrome between 1981 and 1986. The initial procedure successfully divided 69 of 73 pathways identified preoperatively, including 39 of 40 left free wall pathways, 23 of 24 posteroseptal pathways, six of seven right free wall pathways, and one of two anteroseptal pathways. Three additional pathways were identified for the first time during follow-up. The primary procedure was successful in curing 53 (88%) of the 60 patients and in dividing 69 (91%) of the total of 76 pathways. Subsequent procedures increased the overall clinical cure rate to 97%. The surgery was performed with low morbidity and no perioperative or late mortality. Patients were followed-up for a mean of 6.4 years (range four to nine years). No patient showed clinical or electrocardiographic evidence of recurrence of a pathway which had been divided surgically. We conclude that regardless of pathway site, surgical treatment carries a low risk and has a high probability of avoiding lifelong antiarrhythmic therapy.

Adolescent↗

A new technique of internal cardiac cooling improves atrial protection.

We developed a technique for selectively cooling the right heart during cardioplegic arrest by intracavitary right atrial (RA) perfusion with cold blood. In dogs during hypothermic cardioplegic arrest, we compared the effects on myocardial temperature of RA perfusion and two snared caval cannulas with three methods of venous cannulation without perfusion: a two-stage atriocaval cannula, two caval cannulas and two snared caval cannulas. The mean atrioventricular (AV) node temperature with RA perfusion (16.5 degrees +/- 0.4 degrees C) was significantly lower than with the atriocaval cannula (25.1 degrees +/- 0.2 degrees C), two caval cannulas (25.2 degrees +/- 0.3 degrees C) or two snared caval cannulas (21.6 degrees +/- 0.2 degrees C) (p less than 0.01, RA perfusion versus other groups). The results for RA wall temperature showed a similar pattern. RA perfusion produced similar results in 6 patients undergoing coronary artery bypass grafting. We conclude that hypothermic protection of the right atrium and AV node is inadequate with conventional techniques of cannulation and cooling, and may be improved by the use of internal RA cooling.

Animals↗

A digital timing and display unit for intraoperative mapping of cardiac arrhythmias.

An inexpensive display and timing unit incorporating a multichannel signal delay has been developed for mapping the heart during electrophysiological surgery. It provides a continuous digital readout of the time relationships between 3 intracardiac electrograms and the surface electrocardiogram. The electrograms are displayed on a storage oscilloscope with an automatic erase facility. This unit is used to locate accessory atrioventricular connections in the Wolff-Parkinson-White syndrome, to map ventricular tachycardias and to locate the bundle of His. The design has been refined during 5 years of use in over 200 operative procedures.

Arrhythmias, Cardiac↗

Repair of ventricular septal defect in the first two years of life using profound hypothermia-circulatory arrest techniques.

Ventricular septal defect repair had been performed in 57 infants ages 21 days to 21 months and under 10 kg in weight using profound hypothermia-circulatory arrest technics. Severe congestive heart failure was the indication for operation in all but two infants under 6 months of age, and in those under 3 months there was usually an associated moderate or large sized atrial septal defect or patent ductus arteriosus or a coarctation. In infants over 6 months controlled heart failure was accompanied by failure to thrive and often recurrent respiratory infections. The main indication for surgery in three infants was repeated severe respiratory infections and in 7 infants, ages 10-15 months, an elevation of pulmonary vascular resistance of 6 units M2 or more. There were two hospital deaths among the 49 infants without coarctation (ages 6 and 20 months) and two among the 8 with coarctation. Postoperative respiratory and other complications were uncommon. On late review there was no significant residual VSD amongst the 11 recatheterized patients. Psychometric studies in 19 children who had reached the age of three to four years gave no evidence of cerebral damage due to the circulatory arrest period. In view of these results palliative pulmonary artery banding is no longer performed for VSD in infancy unless there is a Swiss cheese septum or an associated severe coarctation.

Aortic Coarctation↗