Circulation
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Comparative Study
Effect of normothermic blood cardioplegia on postoperative conduction abnormalities and supraventricular arrhythmias.
Conduction defects and supraventricular tachycardia (SVT) are common after myocardial revascularization using current methods of cold hyperkalemic blood or crystalloid cardioplegia. The current retrospective study was undertaken to assess the influence of normothermic blood cardioplegia on conduction defects and SVT. ⋯ Normothermic cardioplegia is associated with a marked decrease in new and permanent conduction disturbances and postoperative CK-MB release. This suggests that a significant factor in the pathogenesis of conduction blocks is cold-related injury. Supraventricular arrhythmias were not affected by the type of cardioplegia given.
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Comparative Study
Global left ventricular performance and regional systolic function after suture annuloplasty for chronic mitral regurgitation.
In surgery for chronic mitral regurgitation, the mitral subvalvular apparatus, including annulus, may play an important role in preserving left ventricular (LV) performance. The suture annuloplasty for mitral regurgitation allows annular contraction of the mitral valve. The potential effects of suture annuloplasty on the postoperative LV performance have not been fully defined. ⋯ These data suggest that suture annuloplasty can provide more desirable postoperative LV systolic performance than conventional MVR by preserving both the contraction of the mitral annulus and the mitral valvular-ventricular interaction.
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Acute bacterial endocarditis continues to be a condition with high morbidity. Although the majority of patients are treated by high-dose antibiotics, a high-risk patient group requires surgical intervention, which is the subject of this article. ⋯ The morbidity and mortality after surgical treatment of acute endocarditis depend on the site, the severity, and the subject infected. Early aggressive surgical intervention is indicated to optimize surgical results, especially in patients with nonstreptococcal infection or PVE.
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beta-Adrenergic receptor blockade has been reported to improve hemodynamics and beta-adrenergic receptor-adenylate cyclase function in idiopathic dilated cardiomyopathy. The purpose of this study was to determine the effects of beta-adrenergic receptor blockade on the beta-adrenergic receptor system and myocardial function in a model of compensated ischemic heart failure. ⋯ After large MI in rats, there is impaired papillary muscle function with decreased beta-adrenergic receptors and adenylate cyclase activity in the noninfarcted myocardium. Propranolol treatment improved basal isometric muscle function and beta-adrenergic receptor density in rats after myocardial infarction but did not improve adenylate cyclase activity or isoproterenol-stimulated muscle function. These data suggest that there is a primary defect in adenylate cyclase function that persists despite upregulation of receptors with propranolol treatment.
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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.