CET Lead Placement & Recording Procedures

Question 1

What is the correct placement for the V1 lead in a 12-lead ECG?

Accepted Answer

Fourth intercostal space, right of the sternum

Answer

The correct placement for the V1 lead in a 12-lead ECG is the fourth intercostal space, just to the right of the sternum. This precise anatomical positioning is critical for accurately capturing the electrical activity from the right side of the heart. Proper lead placement ensures that the ECG tracing provides a standardized and comprehensive view of cardiac function, which is essential for diagnosis.

Question 2

Why is it important to avoid placing limb leads over bony areas?

Accepted Answer

They interfere with conductivity and cause inaccurate readings

Answer

Placing limb leads over bony areas interferes with conductivity because bone has higher electrical impedance compared to muscle and soft tissue. This poor contact between the electrode and the skin impedes the transmission of the heart's electrical signals. Consequently, it can lead to signal interference, artifacts, and inaccurate ECG readings, compromising the diagnostic quality of the tracing.

Question 3

What color is typically used for the left arm electrode in a standard ECG?

Accepted Answer

Black

Answer

In the standard American Heart Association (AHA) color code for ECG limb leads, the left arm electrode is typically black. Standardized color-coding systems are essential for ensuring consistent and correct electrode placement across different healthcare settings. This helps prevent lead misplacement errors, which could lead to inaccurate ECG interpretations and potentially incorrect diagnoses.

Question 4

How should the skin be prepared before placing electrodes?

Accepted Answer

Shave and clean the skin with alcohol

Answer

Proper skin preparation, including shaving excess hair and cleaning with alcohol, is vital for obtaining a high-quality ECG. Hair can obstruct electrode contact, while oils, dirt, and dead skin cells increase skin impedance. This preparation ensures optimal electrical conductivity and secure adhesion of the electrodes, minimizing artifacts and improving the clarity and accuracy of the ECG signal.

Question 5

Which lead records electrical activity between the right arm and left leg?

Accepted Answer

Lead II

Answer

Lead II is a bipolar limb lead that records the electrical activity between the right arm (negative electrode) and the left leg (positive electrode). This lead is particularly important as it often aligns with the heart's general electrical axis, providing a clear view of atrial and ventricular depolarization and repolarization. It is frequently used for rhythm strip analysis due to its prominent P, QRS, and T waves.

(CET) Certified Electrocardiogram Technician Practice Test

(CET) Certified Electrocardiogram Technician Practice Test

CET Lead Placement & Recording Procedures