Progressive Care Nursing Certification (PCCN) Practice Exam

Occlusion of the right coronary artery increases the risk of which type of heart block?

1. Mobitz type I

2. Mobitz type II

3. complete heart block

4. first-degree AV block

The correct answer is: Mobitz type I

Occlusion of the right coronary artery is associated with increased risks for specific types of heart block due to the heart's anatomical and electrical conduction pathways. In this scenario, Mobitz type I, also known as Wenckebach, is often linked to right coronary artery issues. The reason Mobitz type I is the correct answer lies in the nature of how this form of heart block occurs. Mobitz type I involves progressive lengthening of the PR interval until a beat is dropped. This type of block tends to emerge from issues within the AV node, which is often affected by ischemia or infarction in the territory supplied by the right coronary artery. Therefore, when the right coronary artery is occluded, the vascular supply to the AV node may be compromised, leading to the development of Mobitz type I heart block. Other options, such as Mobitz type II and complete heart block, involve different mechanisms and are generally associated with more severe structural heart disease or damage to the bundle branches or distal conduction pathways rather than solely the AV node's ischemia. First-degree AV block, while also involving delayed conduction through the AV node, does not exhibit the characteristic progressive PR interval lengthening seen in Mobitz type I and is less likely to be directly attributed