No abstract

CPB alone appears sufficient to elicit the PC response important for myocardial protection during cardiac surgery. These data suggest that myocardial alpha-adrenergic receptor and adenosine receptor stimulation are involve in initiating CPB-induced PC.

No abstract

Between January 1985 and April 1994, 42 children aged between 7 and 14 years (mean 11.3 years) underwent repair of severely incompetent rheumatic mitral valves with no accompanying mitral stenosis. In 19 patients the tricuspid valve was severely incompetent, while 8 patients had severe aortic incompetence. Overall, the repair incorporated shortening of elongated tendinous cords and insertion of a Duran or Carpentier prosthetic ring. The repair was the sole procedure in 15 patients, whilst 19 patients also had a De Vega tricuspid valvar annuloplasty and 8 had repair or replacement of the aortic valve. There were no hospital deaths. Postoperative transthoracic echocardiographic studies revealed trivial residual mitral valvar regurgitation in 6 patients, mild regurgitation in 18, moderate in 15, and regurgitation severe enough to warrant replacement of the mitral valve in 3 patients. The mean follow-up period was 37 months (maximum 120 months, minimum 1 month). Of 39 patients followed-up, 28 attended for more than 5 years. Of these, 7 underwent replacement of the mitral valve for severe regurgitation within 4 years of the repair. Severe mitral regurgitation in 3 patients was controlled by medical therapy. One was eventually lost to follow-up, and one patient died of causes unrelated to surgery. The remaining 16 patients had absent to moderate mitral valvar regurgitation. These results contrast with 10 repairs of congenital mitral incompetence, where no patients required re-operation in the immediate 5 years period of follow-up. Every effort should be made in children with rheumatic mitral incompetence to preserve the natural valve by conservative repair, despite the fact that repair of the incompetent rheumatic mitral valve is not so durable as repair of congenitally incompetent valves.

The outcome of coronary bypass surgery was analyzed in 25 patients who were on thyroxin replacement therapy for chronic thyroid disorders at the time of operation. It was hypothesized that if such patients were given only their routine dose of thyroxin on the day of surgery, hemodynamic and cardiorespiratory recovery may be poor. All the patients on thyroxin replacement therapy were given their routine dose of thyroxin orally or via a nasogastric tube in the perioperative period. No supplemental dose was used. Based on preoperative levels of thyroid stimulating hormone, 68% of these patients were biochemically hypothyroid prior to surgery. Analysis of a large number of variables showed no difference in outcome against a control group who had no previous thyroid problems. We conclude that routine thyroxin administration is all that is required for a satisfactory outcome in patients undergoing coronary bypass surgery while on thyroxin replacement therapy.