Question

Mobitz type 2 second degree AV block is seen in all except:

• A. Hypothyroidism
• B. Coronary Artery Disease
• C. Sarcoidosis
• D. Cushing syndrome

Answer 1

The Correct Option is D

Mobitz type 2 second degree AV block is a pathological condition characterized by intermittent non-conducted P waves without progressive prolongation of the PR interval. This condition is associated with structural problems within the conduction system of the heart, typically due to diseases affecting the atrioventricular (AV) node or His bundle. Knowing which conditions are commonly associated with this type of AV block can aid in diagnosis and management.

Let's examine the options provided:

• Hypothyroidism: This condition can cause various cardiac manifestations, including bradycardia and heart block. Electrophysiological changes are associated with slowed conduction, making hypothyroidism a possible contributor to Mobitz type 2 block.
• Coronary Artery Disease (CAD): CAD can lead to ischemic changes in the heart's conduction system, potentially causing AV block. Mobitz type 2 second degree AV block may arise if the ischemic damage affects the AV node.
• Sarcoidosis: This inflammatory disease can involve the heart (cardiac sarcoidosis), leading to conduction system abnormalities, including types of AV block. Granulomas infiltrating the AV node can lead to a Mobitz type 2 block.
• Cushing Syndrome: This condition typically involves excessive cortisol production and does not directly affect cardiac conduction pathways in a way that typically results in a Mobitz type 2 block. Therefore, it's the exception among the provided options.

In conclusion, out of the given choices, such as hypothyroidism, coronary artery disease, and sarcoidosis, which are known to affect the cardiac conduction system, Cushing syndrome is the condition least likely to present with Mobitz type 2 second degree AV block.