Pharmacology

Cardiovascular Pharmacology

Cardio pharmacodynamics of digitalis is most frequently used to increase the adequacy of the circulation in patients with CCF and to slow the ventricular rate in patients with atrial fibrillation or flutter NB. The main action of digitalis is its ability to increase myocardial contractility and its positive isotropic action resulting in increased cardiac output, decreased heart size, decreased venous pressure, decreased circulating blood volume, diuresis and relief of edema as digitalis frequently causes a dramatic reduction in the ventricular rate. It was originally believed that this was the main effect subsequently shown to be beneficial irrespective of the HR, its predominant effects being on contractility in addition to the cardiac effects, digitalis has a direct action on vascular smooth muscle, neural tissue. The later being responsible for indirect cardiac actions of the drug which frequently result in reflex autonomic & hormonal changes which affect the CVS.  The circulatory system is busy providing oxygen and nourishment to every cell of the body, let's not forget that the heart, which works hardest of all, needs nourishment.