ECG Rhythm Interpretation Flashcards

A rhythm strip shows no identifiable P waves and a chaotic, irregularly irregular baseline with a ventricular rate of 130 bpm. What rhythm is this?

Answer: Atrial fibrillation

Absent P waves with an irregularly irregular ventricular response is the hallmark of atrial fibrillation.

A sawtooth baseline pattern with atrial waves at about 300 bpm and a regular 2:1 ventricular response best describes which rhythm?

Answer: Atrial flutter

The sawtooth flutter waves near 300 bpm with a fixed conduction ratio are classic for atrial flutter.

On a normal ECG, which part of the conduction system creates the brief pause seen in the PR interval?

Answer: AV node

The AV node deliberately delays the impulse, producing the PR interval and allowing ventricular filling.

A wide-complex regular tachycardia at 180 bpm with no visible P waves is most concerning for which rhythm?

Answer: Ventricular tachycardia

A regular wide-QRS tachycardia without P waves should be treated as ventricular tachycardia until proven otherwise.

Which finding on a rhythm strip indicates a normal sinus rhythm?

Answer: Upright P wave before every QRS at 60-100 bpm

Normal sinus rhythm shows a consistent upright P wave preceding each QRS at a rate of 60-100 bpm.

A rhythm shows a rate of 45 bpm with normal P waves, PR intervals, and QRS complexes. What is this rhythm?

Answer: Sinus bradycardia

A normal sinus pattern with a rate below 60 bpm is sinus bradycardia.

In ventricular fibrillation, the ECG most characteristically shows what?

Answer: Chaotic waveforms with no identifiable QRS complexes

Ventricular fibrillation produces disorganized, chaotic deflections with no discernible QRS complexes.