Digitalis is a drug that directly enhances myocardial contractility and increases the volume of blood per beat, resulting in a decrease in end-systolic residual volume and a decrease in end-diastolic pressure, which helps to relieve stasis in various organs. The mechanism of action of digitalis to increase myocardial contractility is through the inhibition of cell membrane sodium, potassium and ATP coenzymes by digitalis, resulting in increased intracellular calcium inward flow and enhanced myocardial contractility. Myocardial contraction is enhanced, which can increase myocardial oxygen consumption, but the reduction of ventricular cavity and ventricular wall tension can decrease myocardial oxygen consumption, thus digitalis preparations can improve myocardial work capacity without increasing myocardial oxygen consumption.