CRAT Sinus Rhythm Interpretation 2

Question 1

Normal sinus rhythm requires which set of criteria?

Accepted Answer

Regular P waves upright in II and inverted in aVR, constant PR 120-200 ms, rate 60-100 bpm, narrow QRS

Answer

P waves inverted in II, rate 60-100 bpm

Answer

PR interval greater than 200 ms, rate 60-100 bpm

Answer

Rate 60-100 bpm with no P waves

Question 2

Sinus bradycardia is defined as sinus rhythm at a rate below which threshold?

Accepted Answer

60 bpm

Answer

50 bpm

Answer

40 bpm

Answer

100 bpm

Question 3

Sinus arrhythmia is best described as which pattern?

Accepted Answer

Irregular R-R intervals that vary with respiration, with all other sinus rhythm criteria intact

Answer

Irregular rhythm due to multiple P wave morphologies

Answer

Irregular rhythm with absent P waves

Answer

Regular rhythm with variable PR intervals

Question 4

A sinus pause is defined as an absence of the expected sinus beat lasting at least how long?

Accepted Answer

Two or more seconds (or twice the preceding R-R interval)

Answer

0.5 seconds

Answer

500 ms

Answer

One cardiac cycle only

Question 5

A patient's rhythm strip shows a regular rhythm at 55 bpm with upright P waves in lead II and a PR interval of 160 ms. How should this rhythm be classified?

Accepted Answer

Sinus bradycardia

Answer

Junctional rhythm

Answer

Normal sinus rhythm

Answer

First-degree AV block with sinus bradycardia

Question 6

Sinus tachycardia is most appropriately managed by which approach?

Accepted Answer

Identifying and treating the underlying cause (fever, pain, hypovolemia, anxiety, hyperthyroidism)

Answer

Immediate cardioversion

Answer

IV beta-blockers as first-line treatment always

Answer

Adenosine administration