Circulation
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
A randomized comparison of external and internal cardioversion of chronic atrial fibrillation.
Delivery of shocks within the right atrium has been reported to be more effective than conventional external shocks in converting atrial fibrillation (AF), but these two cardioversion techniques have never been compared prospectively. The purpose of this study was to compare the efficacies of external and internal cardioversion in patients with chronic AF unresponsive to prior attempts at electrical and/or pharmacological cardioversion. Low-dose amiodarone was used in all patients after cardioversion to suppress recurrences of AF. ⋯ Internal cardioversion is more effective than external cardioversion in restoring sinus rhythm and is as safe as external cardioversion in patients with chronic AF. The recurrence rate of AF is the same after both types of cardioversion. If conventional electrical cardioversion is ineffective, internal cardioversion should be attempted. The combination of low-dose amiodarone and external or internal cardioversion may result in maintaining sinus rhythm long-term in patients with refractory AF.
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Comparative Study
Differences in vasomotor control between human gastroepiploic and left internal mammary artery.
Internal mammary artery grafts have a greater long-term patency rate than do saphenous vein grafts. This has in part been attributed to the difference in endothelial function of arterial and venous vessels. The use of the gastroepiploic artery in coronary artery bypass grafting has become popular recently because of its similarity to internal mammary artery. In this study, we compared the endothelial responses of gastroepiploic and left internal mammary arteries to vasoactive substances. ⋯ The resemblance of relaxations induced by metacholine and sodium nitrite in both gastroepiploic and left internal mammary arteries suggests a similar activation and behavior of the L-arginine pathway in both arteries. The difference in bradykinin-induced relaxations may reflect a prostaglandin metabolism in the gastroepiploic artery different from that in the left internal mammary artery. Furthermore, maximal metacholine-induced relaxation in rings of the left internal mammary artery shows an age dependency that was not observed in rings of the gastroepiploic artery.
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Conventional cardiopulmonary resuscitation (CPR) for cardiac arrest after open-heart surgery in children is often unsuccessful despite the ability to perform open-chest massage. The purpose of this study was to review our results with mechanical support as rescue therapy in children with sudden circulatory arrest after cardiac surgery. ⋯ We conclude that ECMO rescue in children with postcardiotomy cardiac arrest is a feasible option in selected patients even after prolonged CPR (as long as 60 minutes).
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Randomized Controlled Trial Comparative Study Clinical Trial
Alternative techniques of cardioplegia.
Although normothermic cardioplegia has been used with acceptable clinical results, no studies have previously been performed to determine the metabolic consequences of these various techniques of myocardial protection. Therefore, we have performed a randomized clinical trial to assess the effects of three cardioplegic techniques on myocardial metabolic recovery. ⋯ Intermittent cold cardioplegia inhibited mitochondrial function but prevented the degradation of adenine nucleotides. Warm antegrade cardioplegia had the greatest myocardial oxygen consumption, and warm retrograde cardioplegia had the greatest anaerobic lactate production. There were no differences in clinical outcomes between cardioplegic groups.
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Randomized Controlled Trial Comparative Study Clinical Trial
Aprotinin prevents cardiopulmonary bypass-induced platelet dysfunction. A scanning electron microscope study.
Administration of aprotinin during extracorporeal circulation reduces blood loss and improves platelet function. ⋯ By preserving platelet function, aprotinin improves postoperative hemostasis in all patients who receive high dose and in most who receive low dose.