Certified Registered Nurse Anesthetist (CRNA) Practice Exam

Which leads correspond with the septal leads in an electrocardiogram?

1. V1, V3, V4

2. V1, V2

3. V2, V5

4. V3, V4

The correct answer is: V1, V2

In an electrocardiogram (ECG), the septal leads are specifically designed to reflect electrical activity in the interventricular septum, which separates the right and left ventricles. The leads that correspond to this area are V1 and V2. These leads are located in a position on the chest that is strategically placed over the heart's septal region, allowing them to detect electrical changes occurring in that specific area. V1 is positioned at the right fourth intercostal space, just to the right of the sternum, while V2 is at the left fourth intercostal space, just to the left of the sternum. Together, these leads capture the electrical signals that originate from the septal wall during the cardiac cycle, making them vital for assessing conditions like anterior myocardial infarctions or disturbances in septal function. The other options represent leads that do not particularly focus on the septal region. For example, V3 and V4 primarily cover the anterior wall of the left ventricle, while V5 is more lateral, providing information about the left lateral wall. Thus, the choice identifying V1 and V2 as the correct septal leads aligns perfectly with their designated functions in the electrocardiogram.