Progressive Care Nursing Certification (PCCN) Practice Exam

In a patient with mitral stenosis, what anatomical change contributes to atrial fibrillation?

1. Decreased left ventricular compliance

2. Increased left atrial pressure and dilation

3. Left ventricular hypertrophy

4. Pulmonary artery hypertension

The correct answer is: Increased left atrial pressure and dilation

In patients with mitral stenosis, the underlying anatomical change that contributes to atrial fibrillation is the increased left atrial pressure and dilation. Mitral stenosis causes a narrowing of the mitral valve, which impedes the normal flow of blood from the left atrium to the left ventricle during diastole. This obstruction increases the pressure within the left atrium, leading to its enlargement or dilation over time. As the left atrium dilates, the atrial myocardium undergoes structural changes that can disrupt the normal electrical conduction pathways. This disruption creates an environment conducive to the development of atrial fibrillation, as the enlarged atrial tissue can lead to abnormal electrical impulse formation and conduction. The presence of atrial fibrillation is particularly concerning because it can result in inadequate blood flow and increase the risk of thromboembolic events, such as stroke. The other options do not directly reflect the primary change associated with atrial fibrillation in mitral stenosis. For instance, decreased left ventricular compliance and left ventricular hypertrophy are more relevant to conditions affecting the left ventricle rather than the changes specific to the left atrium that lead to arrhythmias. Similarly, pulmonary artery hypertension may develop as a consequence of mit