Unstable angina. Rational approach to management.

摘要: Unstable angina can be defined by the development of chest pain at rest, usually with reversible S-T segment changes. It has been found in patients whom developed rest cardiac catheterization laboratory that a decrease coronary sinus oxygen saturation preceded changes left ventricular relaxation and contractility and/or electrocardiographic Increases heart rate blood pressure followed, rather than preceded, these ischemic episodes. These findings suggest supply, an increase demand, is cause episodes rest. Although principles treatment effort have emphasized reduction myocardial should logically emphasize therapies improve supply. A stepwise approach to admitted Coronary Care Unit unstable proposed. The initial step consists replacing oral transcutaneous nitrates intravenous infusion nitroglycerin while maintaining beta-blockers calcium blockers their previous doses. Nitroglycerin dilates arteries intercoronary collateral channels addition reducing preload afterload. Intravenous administration allows faster titration effective dose also more rapid reversal hemodynamic effects, if patient's status second would consist adding or increasing channel blockers. Slow dilate prevent reverse spasm third subgroups resting tachycardia arterial hypertension. fourth final employ intra-aortic balloon counterpulsation therapy perform urgent angiography. In suitable anatomy, angiography could followed percutaneous transluminal angioplasty artery bypass surgery.