Which condition is most commonly associated with multifocal atrial tachycardia?

• A. Chronic obstructive pulmonary disease (COPD)
• B. Coronary artery disease
• C. Aortic stenosis
• D. Myocardial infarction

Answer: (A)

Multifocal atrial tachycardia (MAT) is most commonly associated with chronic obstructive pulmonary disease (COPD) due to the increased pulmonary pressure and subsequent cardiac strain that these respiratory conditions can cause. In patients with COPD, the hypoxia and hypercapnia can lead to increased sympathetically mediated catecholamine release, which can trigger abnormal atrial firing from multiple foci. This results in the characteristic features of MAT, where there are varying P-wave morphologies and a rapid atrial rate.

Other conditions may have some association with atrial arrhythmias but do not specifically have the same strong link to MAT as COPD does. For instance, coronary artery disease and myocardial infarction can lead to changes in the heart's structure and electrical conduction system but are more often associated with other types of atrial arrhythmias, such as atrial fibrillation. Aortic stenosis primarily affects the left ventricle and may lead to other arrhythmias, but it is not specifically linked to MAT. Therefore, the strong correlation between COPD and MAT makes it the correct response.