Agents for Treating Heart Failure - Chapter 44

Q&A flashcards covering key concepts from the lecture notes on heart failure pharmacotherapy (Chapter 44).

What is the preferred first-line therapy combination for HFrEF Stage C according to ACC/AHA guidelines?

ARNI (preferred) or ACEI/ARB with an evidence-based beta-blocker and a diuretic as needed.

Name add-on therapies available for Stage C HFrEF patients who have persistent symptoms or volume overload.

Aldosterone antagonist, SGLT2 inhibitor, diuretic agent, hydralazine with isosorbide dinitrate, and ivabradine (in select patients).

What is the mechanism of action of cardiac glycosides like digoxin?

Increase intracellular calcium in cardiac myocytes, increasing contractility; slows AV node conduction; increases cardiac output.

For what conditions is digoxin used in heart rhythm disorders?

Heart failure, atrial flutter, atrial fibrillation, and paroxysmal atrial tachycardia.

What dosing approach can be used for rapid onset when starting digoxin?

Loading (rapid) dose to achieve quick therapeutic effect.

How is digoxin eliminated from the body?

Excreted unchanged in the urine; caution in renal impairment.

What is the therapeutic plasma concentration range for digoxin?

0.5–2 ng/mL.

List some signs of digoxin toxicity.

Anorexia, nausea/vomiting, malaise, depression, irregular heart rhythms; vision changes such as yellow halos.

What is the antidote for digoxin toxicity?

Digoxin immune Fab.

What apical pulse should prompt withholding digoxin?

Hold if apical pulse is <60 bpm for a full minute.

How should intravenous digoxin be administered?

Infuse slowly over at least 5 minutes.

What daily monitoring is recommended for patients on digoxin?

Weigh the patient daily and monitor for signs of toxicity.

What is milrinone and its primary action?

A phosphodiesterase-3 inhibitor that increases cAMP, raising intracellular calcium and contractility; used for short-term HF not responding to other therapies.

In which scenarios is milrinone indicated?

Short-term treatment of HF not responding to digoxin or diuretics alone or with poor response to these and vasodilators.

What are major adverse effects of milrinone?

Ventricular arrhythmias, hypotension, chest pain, GI effects, thrombocytopenia, hypersensitivity.

What important drug interaction exists with milrinone and furosemide?

Furosemide precipitates when mixed; administer at different IV sites.

What is Ivabradine and what does it affect?

A hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker that slows the SA node pacemaker, reducing heart rate.

What are common side effects and contraindications of ivabradine?

Bradycardia, hypertension, A-fib, luminous phenomena; contraindicated if pacemaker-dependent, liver impairment, or use with CYP3A4 inhibitors.

What is an ARNI and what are its two components in Entresto?

ARNI is an angiotensin receptor neprilysin inhibitor; Entresto combines valsartan (ARB) and sacubitril (neprilysin inhibitor).

What adverse effects are associated with ARNI therapy?

Hypotension, hyperkalemia, cough, dizziness, renal impairment.

What does neprilysin inhibition achieve in heart failure therapy?

Prevents breakdown of natriuretic peptides, increasing diuresis, natriuresis, and vasodilation.

What is the role of ACE inhibitors/ARBs in congestive heart failure?

Reduce afterload and preload by blocking angiotensin II/aldosterone signaling.

What is the role of beta-blockers in HFrEF?

Inhibit negative remodeling from chronic sympathetic activation; improve outcomes when used with guideline-directed medical therapy.

What are the two classes of cardiotonic agents?

Cardiac glycosides (e.g., digoxin) and phosphodiesterase inhibitors (e.g., milrinone).