Certified Cardiovascular Technician Practice Exam

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Prepare for the Certified Cardiovascular Technician Exam. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

If the left arm and right leg leads are reversed, which of the following would likely occur on the ECG?

Lead I becomes like lead II
Flat line in lead I
Identical readings in lead I and lead II
Lead aVF becomes inverted

The correct answer is: Lead I becomes like lead II

When the left arm and right leg leads are reversed, it alters the electrical vector that is being measured by the electrocardiogram (ECG). Specifically, Lead I is normally constructed by measuring the electrical potential difference between the left arm and the right arm. If the left arm lead is swapped with the right leg lead, the heart's electrical axis as calculated will change. Under usual circumstances, Lead I captures the electrical activity from the left arm to the right arm, while Lead II captures the electrical activity from the right arm to the left leg. If you reverse the leads, the electrical vector being measured for Lead I would mimic the relationship captured by Lead II. This is because the electrical signal's perspective shifts due to the re-positioning of the leads, leading to an effect where Lead I effectively illustrates similar dynamics as Lead II at an altered axis. Hence, Lead I ends up exhibiting characteristics akin to those of Lead II. This change demonstrates the principle of how lead placement influences the ECG readings. The other options either result from different lead placements that wouldn’t occur with this specific swapping or reflect interpretations of the ECG that wouldn’t apply when simply reversing the aforementioned leads.