Certified Emergency Nurse (CEN) Practice Test

In the context of myocardial infarction (MI) involving the posterior descending artery, a common clinical feature is the presence of tall R waves in V1 and V2. This observation is characteristic of a posterior wall infarction as the electrical activity is disrupted when the heart muscle is injured in that region.

When the posterior descending artery is compromised, it impacts the heart's electrical conduction pathways, leading to variations in the EKG readings. The tall R waves in the right precordial leads (V1 and V2) can occur due to the transition of electrical forces from the back of the heart toward the anterior wall, demonstrating the effects of the posterior MI.

Other features of a posterior MI might include reciprocal ST segment changes in the anterior leads, and this pattern helps clinicians identify the MI's location. Tall R waves are distinct in this situation and provide critical information in understanding the patient's cardiac status.

In contrast, the other options do not accurately describe the usual indicators of a posterior descending artery MI. For example, ST elevation in leads 2, 3, and aVF typically points toward an inferior MI involving the right coronary artery rather than a posterior MI. Similarly, elevation in arterial blood pressure is not a consistent finding, as blood pressure may vary