What is the primary function of digitalis in patient care?

Digitalis, which is derived from the foxglove plant, primarily functions by increasing the strength of cardiac contractility. This effect is particularly beneficial for patients with heart failure or certain types of arrhythmias. The enhanced contractility—also known as positive inotropic effect—enables the heart to pump more efficiently, thereby improving cardiac output and overall circulation. This mechanism helps alleviate symptoms associated with decreased heart function, such as fatigue and shortness of breath, and can contribute to better exercise tolerance in patients with heart failure.

By directly impacting myocardial cell function through the inhibition of the sodium-potassium ATPase pump, digitalis influences intracellular calcium levels, resulting in stronger heart contractions. This attribute makes digitalis a critical component in the management of heart failure and other cardiac conditions. The other options provided do not encapsulate the primary function of digitalis in patient care, focusing instead on effects that digitalis does not primarily achieve.