Drugs and the cardiovascular system

Abstract

The function of the cardiovascular system is to deliver oxygen and nutrients to the tissues. Failure of the cardiovascular system will result in tissue hypoxia. There are many categories of drugs that can be used to support the cardiovascular system by acting on the heart (pump) and/or the vessels (conduit). Many of these drugs act on the autonomic nervous system through various receptors and ion channels. Inotropes improve the contractility of the heart, whilst antiarrhythmic agents restore sinus rhythm and optimise heart rate for maximal efficiency of the pump. The oxygen delivery to the myocardium is maintained with the aid of coronary vasodilators in patients with ischemic heart disease. Vasopressors are administered to increase perfusion pressure and so improve flow, whilst vasodilators are used to treat hypertension which helps to decrease the work of the heart, while improving the blood flow to the myocardium. Most drugs administered to improve the function of the cardiovascular system have multiple mechanisms of action and may have more than one effect on the cardiovascular system, so they must be administered with caution and titrated to effect, and their effects monitored closely.