AF Pathophysiology 3

Question 1

Which of the following best explains why patients with hypertrophic cardiomyopathy (HCM) have a high prevalence of AF?

Accepted Answer

Left atrial dilation and fibrosis secondary to diastolic dysfunction and outflow obstruction

Answer

In HCM, diastolic dysfunction and elevated filling pressures cause left atrial enlargement and fibrosis, providing ideal substrate for AF initiation and maintenance.

Question 2

In AF with rapid ventricular response, tachycardia-induced cardiomyopathy can develop. What is the primary mechanism?

Accepted Answer

Calcium overload and impaired energy metabolism from sustained rapid ventricular rates

Answer

Chronic rapid ventricular rates cause intracellular calcium overload, mitochondrial dysfunction, and energy depletion, leading to reversible ventricular systolic dysfunction.

Question 3

Which electrophysiological feature distinguishes 'long-standing persistent' AF from 'persistent' AF in terms of underlying pathophysiology?

Accepted Answer

Greater degree of structural remodeling, fibrosis, and loss of electrical organization

Answer

Long-standing persistent AF involves advanced atrial structural remodeling with extensive fibrosis that makes spontaneous or induced termination increasingly unlikely.

Question 4

How does mitral stenosis predispose to AF development?

Accepted Answer

Chronically elevated left atrial pressure causes atrial dilation, fibrosis, and conduction heterogeneity

Answer

Mitral stenosis impedes left atrial outflow, raising atrial pressure and causing progressive atrial enlargement and fibrosis that sustains AF.

Question 5

What is the Coumel triangle triad for AF initiation?

Accepted Answer

Trigger, vulnerable substrate, and modulating factors (autonomic nervous system)

Answer

Coumel's triangle describes AF as requiring a trigger (usually ectopic PV activity), a susceptible substrate (fibrosed/remodeled atrium), and modulating factors (autonomic tone).

(AF) Atrial Fibrillation Certification Practice Test

(AF) Atrial Fibrillation Certification Practice Test

AF Pathophysiology 3