EKG Heart Rate & Rhythm Analysis 1 Flashcards
6 cards from real EKG certification Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 EKG Heart Rate & Rhythm Analysis 1 flashcards as text
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?
Answer: 10
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.
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?
Answer: 38 bpm
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.
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?
Answer: Normal sinus rhythm
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.
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?
Answer: Sinus arrhythmia
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.
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?
Answer: Supraventricular tachycardia (SVT)
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.
On a rhythm strip, the R-R interval measures 25 small boxes. Using the small-box method (1500 ÷ number of small boxes), what is the heart rate?
Answer: 60 bpm
The small-box method divides 1500 by the number of small boxes between R waves. 1500 ÷ 25 = 60 bpm, indicating the patient is at the lower boundary of the normal range.