CCT ECG Fundamentals and Leads 2

Question 1

In a standard 12-lead ECG, lead aVR views the heart from which angle?

Accepted Answer

Right shoulder, looking toward the heart's base from above-right

Answer

Lead aVR is the augmented unipolar lead placed at the right arm, providing a view from the right shoulder looking down and toward the heart's base and right side. It is often inverted relative to other leads.

Question 2

Which leads make up the inferior leads on a standard 12-lead ECG?

Accepted Answer

II, III, and aVF

Answer

Leads II, III, and aVF are the inferior leads because their positive electrodes are located near the left foot, providing a view of the inferior wall of the left ventricle, which is supplied by the right coronary artery in most patients.

Question 3

A properly performed 12-lead ECG should be recorded at what standard paper speed?

Accepted Answer

25 mm/second

Answer

The international standard paper speed for ECG recording is 25 mm/second, which makes each small square (1 mm) equal to 0.04 seconds and each large square (5 mm) equal to 0.20 seconds.

Question 4

What does the standard calibration signal on an ECG represent, and what should its amplitude be?

Accepted Answer

1 mV electrical signal that should deflect the stylus exactly 10 mm (2 large squares) upward

Answer

The standard calibration (1 mV) signal should produce a 10 mm deflection on standard gain. This allows the interpreter to verify that the gain setting is correct and that ECG amplitudes can be accurately measured.

Question 5

In Einthoven's triangle, which statement correctly describes the relationship between leads I, II, and III?

Accepted Answer

Lead II = Lead I + Lead III (Einthoven's Law)

Answer

Einthoven's Law states that at any given moment, the voltage in Lead II equals the sum of Lead I and Lead III (II = I + III). This mathematical relationship is the basis of the bipolar limb lead system.

CCT - Certified Cardiographic Technician Exam Practice Test

CCT - Certified Cardiographic Technician Exam Practice Test

CCT ECG Fundamentals and Leads 2