EKG certification Certification EKG Interpretation & Waveforms 1

Question 1

A rhythm strip shows a regular rhythm at 75 bpm with narrow QRS complexes. Each QRS is preceded by a P wave, but the PR interval measures 0.26 seconds. What is the MOST accurate interpretation?

Accepted Answer

First-degree AV block

Answer

Normal sinus rhythm

Answer

Second-degree AV block, Mobitz Type I

Answer

Junctional rhythm

Question 2

On a standard EKG, the QRS complex represents which electrical event in the heart?

Accepted Answer

Ventricular depolarization

Answer

Atrial depolarization

Answer

Ventricular repolarization

Answer

Atrial repolarization

Question 3

A patient's EKG shows ST-segment elevation in leads V1–V4 with reciprocal ST depression in leads II, III, and aVF. Which area of the myocardium is MOST likely affected?

Accepted Answer

Anterior wall

Answer

Inferior wall

Answer

Lateral wall

Answer

Posterior wall

Question 4

Which of the following BEST describes a left bundle branch block (LBBB) on a 12-lead EKG?

Accepted Answer

Wide QRS (≥0.12 s) with a broad, notched R wave in lateral leads (I, aVL, V5–V6)

Answer

Narrow QRS with a tall R wave in V1

Answer

Wide QRS with an RSR' ('rabbit ear') pattern in V1 and a deep S wave in V6

Answer

Prolonged PR interval with normal QRS morphology

Question 5

A rhythm strip reveals a regular ventricular rate of 150 bpm with narrow QRS complexes. P waves are present but are inverted in leads II, III, and aVF and immediately precede each QRS. What is the MOST likely rhythm?

Accepted Answer

Junctional tachycardia

Answer

Sinus tachycardia

Answer

Atrial flutter with 2:1 block

Answer

Ventricular tachycardia

Question 6

On a standard EKG running at 25 mm/s, one large box on the horizontal axis represents how much time?

Accepted Answer

0.20 seconds

Answer

0.04 seconds

Answer

0.10 seconds

Answer

0.40 seconds