EKG certification Certification EKG Heart Rate & Rhythm Analysis 2

Question 1

A patient's EKG strip shows 18 large boxes between two consecutive R waves. What is the approximate heart rate?

Accepted Answer

83 bpm

Answer

Heart rate is calculated by dividing 300 by the number of large boxes between R-R intervals: 300 ÷ 18 ≈ 83 bpm (using interpolation between 3.6 large boxes, yielding approximately 83 bpm).

Question 2

Which method is most accurate for calculating heart rate on an EKG strip with an irregular rhythm?

Accepted Answer

Count R waves in a 6-second strip and multiply by 10

Answer

The 6-second method is preferred for irregular rhythms because it averages the rate over multiple beats rather than relying on a single R-R interval.

Question 3

An EKG rhythm strip shows a regular rhythm with R-R intervals of exactly 20 small boxes apart. What is the heart rate?

Accepted Answer

75 bpm

Answer

Dividing 1500 by the number of small boxes (1500 ÷ 20 = 75) gives a heart rate of 75 bpm.

Question 4

A rhythm is described as regularly irregular with a repeating pattern of progressively longer R-R intervals followed by a dropped beat. Which rhythm does this most likely represent?

Accepted Answer

Second-degree AV block Type I (Wenckebach)

Answer

Wenckebach (Mobitz Type I) is characterized by progressive PR prolongation and R-R shortening until a QRS is dropped, creating a regularly irregular pattern.

Question 5

On a standard 12-lead EKG, what does a narrow QRS complex (less than 0.12 seconds) indicate about the origin of the rhythm?

Accepted Answer

The impulse originates above the ventricles

Answer

A narrow QRS complex indicates supraventricular origin, meaning the electrical impulse travels normally through the His-Purkinje system from above the ventricles.

EKG certification Practice Test

EKG certification Practice Test

EKG certification Certification EKG Heart Rate & Rhythm Analysis 2