Certified Registered Nurse Anesthetist (CRNA) Practice Exam

Which artery is associated with the low lateral leads V5 and V6?

1. RCA

2. LCX

3. LAD

4. Pulmonary artery

The correct answer is: LCX

The correct association of the low lateral leads V5 and V6 is with the left circumflex artery (LCX). This artery supplies blood to the lateral and posterior aspects of the left ventricle, which corresponds to the areas of the heart that V5 and V6 monitor. Lead V5 typically reflects the activity in the left ventricle's lateral wall, while V6 provides additional coverage, also focusing on the lateral wall. In the context of an electrocardiogram (ECG), the activation of these leads can indicate ischemic changes or other cardiac abnormalities related to the territories supplied by the left circumflex artery. Understanding this relationship is crucial for healthcare professionals, particularly in emergency and critical care settings where timely recognition of myocardial ischemia is vital for patient management. The other arteries listed do not correlate with the low lateral leads V5 and V6 in the same way. For instance, the right coronary artery (RCA) primarily supplies the right side of the heart, the left anterior descending artery (LAD) is responsible for the anterior wall, and the pulmonary artery is not directly related to coronary circulation. This knowledge is essential in interpreting ECG findings and consequently in managing cardiac conditions effectively.