A 61-year-old man, recently diagnosed with stage C heart failure, was admitted to the
hospital for a control visit. It was found that he had an ejection fraction of 30% at rest and
a treatment which included digoxin was started. Which of the following cardiovascular
parameters did digoxin most likely increase in this patient?
A. Stroke volume B. Total peripheral resistance C. Oxygen consumption of the heart D. End-diastolic volume E. Heart rate
Stroke volume-learning objective: describe the hemodynamic actions of digoxin in the failing heart.answer: athe increase in stroke volume is a direct consequence of the positive inotropic action of digitalisglycosides.b) digoxin can cause peripheral vasoconstriction in the normal subject, but causes insteadperipheral vasodilation in patients with cardiac failure because the increased cardiac outputoffsets the reactive vasoconstriction.c) digoxin actually decreases oxygen consumption in the failing heart because:1) the increased contractility reduces the left ventricular end diastolic volume and so the stretchof the cardiac fibers (oxygen consumption of the heart is directly proportional to the stretch of thecardiac fibers).2) the increased cardiac output offsets the tachycardia induced by the sympathetic activation.d, e) (see explanation of item c).