EKG certification Certification EKG Heart Rate & Rhythm Analysis 1

Question 1

When using the 6-second strip method to calculate heart rate, the number of R waves counted within the strip is multiplied by which number?

Accepted Answer

10

Answer

A standard 6-second strip multiplied by 10 gives the number of beats per minute. This method is especially useful for irregular rhythms because it averages the rate over a defined time interval.

Question 2

A patient's EKG shows exactly 8 large boxes between two consecutive R waves. Using the large-box (300) method, what is the approximate heart rate?

Accepted Answer

38 bpm

Answer

The large-box method divides 300 by the number of large boxes between R waves. 300 ÷ 8 = approximately 37.5, rounded to 38 bpm, indicating bradycardia.

Question 3

An EKG rhythm strip shows upright, uniform P waves before every QRS complex, a PR interval of 0.16 seconds, a regular R-R interval, and a rate of 78 bpm. This rhythm is most consistent with which of the following?

Accepted Answer

Normal sinus rhythm

Answer

Normal sinus rhythm has a rate of 60–100 bpm, upright and uniform P waves preceding each QRS, a PR interval of 0.12–0.20 seconds, and a regular rhythm — all criteria met here.

Question 4

A CNA notices on an EKG rhythm strip that the R-R intervals lengthen slightly during inspiration and shorten during expiration, but the P wave morphology remains normal. This finding is most consistent with which rhythm?

Accepted Answer

Sinus arrhythmia

Answer

Sinus arrhythmia is a normal variant in which the R-R interval varies with the respiratory cycle. The pacemaker remains the SA node, so P wave morphology stays normal.

Question 5

An EKG strip shows a rapid, narrow-complex rhythm at 190 bpm with no clearly identifiable P waves preceding the QRS complexes. Which rhythm does this most likely represent?

Accepted Answer

Supraventricular tachycardia (SVT)

Answer

SVT produces a rapid rate (often 150–250 bpm) with narrow QRS complexes because conduction through the ventricles is normal. P waves may be absent, hidden, or retrograde. Ventricular tachycardia would show wide QRS complexes.

EKG certification Practice Test

EKG certification Practice Test

EKG certification Certification EKG Heart Rate & Rhythm Analysis 1