A patient asked the nurse what cardiac glycosides do to improve his condition.
What is the nurse's best response?

Choice A rationale

Cardiac glycosides are not known for increasing heart rate. Instead, they tend to decrease heart rate by enhancing vagal tone and increasing the refractory period of the atrioventricular node, which helps in controlling heart rate, especially in atrial fibrillation.

Choice B rationale

Cardiac glycosides actually increase the force of myocardial contractions. They inhibit the sodium-potassium ATPase pump, which leads to an increase in intracellular sodium and calcium levels in the myocardial cells, thus increasing the force of contraction.

Choice C rationale

Cardiac glycosides do not significantly decrease conduction velocity. They primarily affect the contractility and heart rate but their influence on conduction velocity is relatively mild.

Choice D rationale

Cardiac glycosides improve renal blood flow and increase urine output by increasing the cardiac output and reducing the activation of the renin-angiotensin-aldosterone system. This helps in relieving symptoms of heart failure.