ACLS ACLS Cardiac Rhythms and ECG Interpretation 2

Question 1

A patient has third-degree (complete) heart block. Which ECG finding is characteristic?

Accepted Answer

P waves and QRS complexes with no relationship to each other (AV dissociation)

Answer

Progressively lengthening PR interval followed by a dropped beat

Answer

Constant PR interval with occasional dropped QRS

Answer

Narrow QRS at 100 bpm with normal P waves

Question 2

What ECG finding is associated with hyperkalemia that warrants immediate ACLS intervention?

Accepted Answer

Peaked (tall, narrow, tent-shaped) T waves

Answer

Prolonged QT interval

Answer

Delta waves

Answer

ST depression in V1–V3

Question 3

In ACLS, which ECG finding is a classic sign of right ventricular strain in massive pulmonary embolism?

Accepted Answer

S1Q3T3 pattern (S wave in I, Q wave and T inversion in III)

Answer

ST elevation in V1–V4

Answer

Delta waves in multiple leads

Answer

Prolonged PR interval

Question 4

Asystole on ECG appears as what pattern?

Accepted Answer

A flat (isoelectric) line with no electrical activity

Answer

Coarse irregular baseline

Answer

Regular slow wide QRS complexes

Answer

P waves only with no QRS

Question 5

Which ECG finding indicates Wolff-Parkinson-White (WPW) syndrome that is important in ACLS?

Accepted Answer

Short PR interval with a delta wave (slurred QRS upstroke)

Answer

Prolonged QRS with left bundle branch morphology

Answer

Absent P waves with irregular QRS

Answer

Deep Q waves in inferior leads

Question 6

During ACLS, a monitor shows fine ventricular fibrillation (fine VF). What is the correct next step?

Accepted Answer

Defibrillate immediately — fine VF is still a shockable rhythm

Answer

Treat as asystole with epinephrine only

Answer

Begin synchronized cardioversion

Answer

Confirm in two leads and observe for 2 minutes

A patient has third-degree (complete) heart block.Which ECG finding is characteristic?