Heart Failure: Causes and Types

What is the approximate 5-year mortality rate for heart failure?

75%
25%
50% (correct)
90%

What is the most common cause of heart failure in the USA?

Myocardial infarction
Cardiomyopathy
Coronary artery disease (correct)
Hypertension

In systolic failure, what is typically reduced?

Stroke volume
Ejection fraction (correct)
Cardiac output
All of the above

Which type of heart failure is more common in older patients?

Diastolic failure (C) Signup and view all the answers

What is a characteristic of diastolic failure?

Stiffening and loss of adequate relaxation (D) Signup and view all the answers

What is the trend in the prevalence of heart failure?

Increasing (D) Signup and view all the answers

What are the two primary goals of treatment in heart failure?

Reducing symptoms and slowing progression (C) Signup and view all the answers

What is the name of the plant family that provides medically useful cardiac glycosides?

Digitalis (B) Signup and view all the answers

What is the extent of absorption of digoxin after oral administration?

65–80% (A) Signup and view all the answers

Where are cardiac glycosides distributed in the body?

Widely distributed to tissues, including the CNS (A) Signup and view all the answers

How is digoxin primarily eliminated from the body?

Excreted unchanged by the kidneys (C) Signup and view all the answers

What is the relationship between digoxin's renal clearance and creatinine clearance?

Directly proportional (A) Signup and view all the answers

What is the primary mechanism by which cardiac glycosides increase cardiac contractility?

Inhibition of Na+/K+-ATPase, leading to increased intracellular sodium concentration (B) Signup and view all the answers

What is the result of the inhibition of Na+/K+-ATPase by cardiac glycosides?

An increase in intracellular sodium concentration (C) Signup and view all the answers

What is the role of the sodium-calcium exchanger in the mechanism of cardiac glycosides?

It reduces calcium expulsion from the cell (D) Signup and view all the answers

What is the effect of cardiac glycosides on the electrical properties of the heart?

A mixture of direct and autonomic actions (D) Signup and view all the answers

What is the mechanism by which cardiac glycosides increase the free calcium concentration in the vicinity of the contractile proteins?

A two-step process involving Na+/K+-ATPase inhibition and the sodium-calcium exchanger (B) Signup and view all the answers

What is the therapeutic effect of cardiac glycosides?

Positive inotropy (B) Signup and view all the answers

What is the primary effect of cardiac glycosides on the cardiac action potential?

Early and brief prolongation of the action potential (D) Signup and view all the answers

What is the main mechanism by which cardiac glycosides slow AV conduction?

Increasing vagal outflow (D) Signup and view all the answers

What is the consequence of an excessively rapid ventricular rate?

Inadequate time for diastolic filling (B) Signup and view all the answers

What is the effect of larger doses of glycosides on sinus rhythm?

Disturbance of sinus rhythm (D) Signup and view all the answers

What is the result of inhibition of the Na+/K+ pump by glycosides?

Depolarization (A) Signup and view all the answers

What is the potential consequence of slowing AV conduction by cardiac glycosides?

AV block (C) Signup and view all the answers

What is the consequence of increased [Ca2+]i in the cardiac muscle?

Coupled beats followed by ventricular tachycardia and eventually ventricular fibrillation (D) Signup and view all the answers

What is the primary site of digitalis toxicity outside the heart?

Gastrointestinal tract (C) Signup and view all the answers

What is the cause of gastrointestinal toxicity associated with digitalis?

Both direct effects on the gastrointestinal tract and CNS actions (D) Signup and view all the answers

What is a rare effect of digitalis in men?

Gynecomastia (D) Signup and view all the answers

What is a possible CNS effect of digitalis?

Aberrations of color perception (A) Signup and view all the answers