Herz
-
Infection of an intracardiac prosthesis, the incidence of which is about 2.5% among patients having undergone valve replacement, is a serious complication with considerable morbidity and mortality. Early prosthetic valve endocarditis (PVE), with an onset within 60 days of valve replacement, accounts for approximately one-third of all cases, while the remaining two-thirds, occur more than two months postoperatively (late prosthetic valve endocarditis). Prosthetic valve endocarditis is most commonly caused by Staphylococcus epidermidis, less frequently by viridans streptococci, Staphylococcus aureus, and gram-negative bacilli. ⋯ Over the last ten years the overall mortality of prosthetic valve endocarditis was 53.8%; 73.6% in early and 43% in late prosthetic valve endocarditis. More recently, however, the survival rate appears to be improving. In general, the mortality associated with prosthetic valve endocarditis caused by fungi and Staphylococcus aureus is highest and that of streptococci lowest.(ABSTRACT TRUNCATED AT 400 WORDS)
-
We review the hemodynamic effects and clinical usefulness of five natural and synthetic catecholamines. Their actions are best understood by an appreciation of the relative ability of each catecholamine to activate alpha, beta 1 and beta 2 adrenergic receptors in the myocardium and peripheral vasculature. Epinephrine, the first catecholamine isolated, is shown to have little useful role in the therapy of acute myocardial infarction. ⋯ Dobutamine, a new synthetic catecholamine, has primarily beta 1 activity. It increases myocardial contractility with little effect on heart rate or peripheral vascular resistance. It is ineffective in cardiogenic shock, but may eventually be shown to have a role in the treatment of left ventricular failure uncomplicated by severe hypotension.
-
Guidelines for a step-wise plan of treatment of tachycardias have been compiled based on clinical empirical experience and with the aid of surface electrocardiograms, intracardial electrograms and stimulation techniques. The plan is primarily with the aid of surface electrocardiograms, intracardial electrograms and stimulation techniques. The plan is primarily oriented with respect to the antiarrhythmic efficacy, the adverse reactions and the practicability of the respective agents. ⋯ Verapamil and/or ajmaline, are usually very effective for termination of reciprocal tachycardias. Ajmaline or propafenon in combination with a beta-adrenergic blocker is recommended for the prophylactic treatment of reciprocal tachycardia. In patients who additionally have bradycardia, prolonged QT-intervals or pre-excitation syndromes, the guidelines should be modified accordingly.