EKG certification Certification EKG Arrhythmias & Dysrhythmias 1

Question 1

A rhythm strip shows a regular rhythm at 60 bpm with a PR interval of 0.28 seconds that remains constant throughout. QRS complexes are narrow. What is the most likely interpretation?

Accepted Answer

First-degree AV block

Answer

First-degree AV block is defined by a consistently prolonged PR interval (>0.20 seconds) with every P wave followed by a QRS complex and no dropped beats. The rhythm remains regular and the QRS is typically narrow.

Question 2

A patient's EKG shows progressive lengthening of the PR interval over several beats, followed by a non-conducted P wave (dropped QRS), then the cycle repeats. Which dysrhythmia does this describe?

Accepted Answer

Second-degree AV block Type I (Wenckebach)

Answer

Mobitz Type I (Wenckebach) is characterized by progressively lengthening PR intervals until a P wave is not conducted and a QRS is dropped. The pattern then resets and repeats cyclically.

Question 3

On a 12-lead EKG, a patient shows a short PR interval (<0.12 seconds) and a slurred upstroke at the beginning of the QRS complex (delta wave) with a widened QRS. The patient complains of palpitations. What is the most likely diagnosis?

Accepted Answer

Wolff-Parkinson-White (WPW) syndrome

Answer

Wolff-Parkinson-White syndrome presents with a short PR interval, delta wave (slurred initial QRS deflection), and widened QRS due to an accessory pathway (Bundle of Kent) bypassing the AV node and pre-exciting the ventricles.

Question 4

You observe a rhythm strip with no discernible P waves, a regular ventricular rate of 38 bpm, and wide, bizarre QRS complexes. The patient is hemodynamically unstable. What rhythm is this?

Accepted Answer

Idioventricular rhythm

Answer

Idioventricular rhythm originates in the ventricles, producing wide and bizarre QRS complexes at a rate of 20–40 bpm. The absence of P waves and the slow ventricular escape rate distinguish it from junctional rhythms, which produce narrow QRS complexes.

Question 5

A patient's rhythm strip shows a regular P-to-P interval and a regular R-to-R interval, but the PR intervals vary with no consistent relationship between P waves and QRS complexes. The ventricular rate is slower than the atrial rate. What is this rhythm?

Accepted Answer

Third-degree (complete) AV block

Answer

Third-degree (complete) AV block occurs when no atrial impulses conduct to the ventricles. The atria and ventricles beat independently (AV dissociation), resulting in regular but unrelated P waves and QRS complexes, with the ventricular rate slower than the atrial rate.

EKG certification Practice Test

EKG certification Practice Test

EKG certification Certification EKG Arrhythmias & Dysrhythmias 1