ECG Rhythm Interpretation Flashcards
7 cards from real CPR practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 ECG Rhythm Interpretation flashcards as text
A patient has a regular rhythm at 42 bpm with narrow QRS complexes and no visible P waves. What is the most likely escape pacemaker site?
Answer: AV junction (junctional escape)
A junctional escape rhythm presents as a narrow QRS at 40-60 bpm with absent, retrograde, or buried P waves when the SA node fails to pace.
Which ECG change is the earliest and most sensitive indicator of acute myocardial ischemia before ST elevation develops?
Answer: Hyperacute (peaked) T waves
Hyperacute T waves (tall, broad, symmetric) are often the earliest ECG change seen in acute coronary occlusion, appearing before ST elevation.
On a rhythm strip, you notice the QRS complex occurring regularly at 32 bpm with wide, bizarre-looking complexes and no associated P waves. What is this rhythm?
Answer: Ventricular escape rhythm
A ventricular escape rhythm has a rate of 20-40 bpm, wide and bizarre QRS complexes, and represents the last resort pacemaker when higher pacemakers fail.
In lead II, a normal P wave should be upright and less than how many mm tall and less than how many ms wide?
Answer: 2.5 mm tall, 80 ms wide
A normal P wave in lead II should be no taller than 2.5 mm and no wider than 80 ms (0.08 seconds); exceeding these limits suggests atrial enlargement.
A patient with a cardiac pacemaker presents to your unit. The ECG shows a pacemaker spike followed by a QRS complex in some beats but not others. What does this indicate?
Answer: Failure to capture
Failure to capture occurs when a pacemaker spike is present but fails to depolarize the myocardium, resulting in pacing spikes not followed by QRS complexes.
You are treating a patient in stable wide-complex tachycardia at 170 bpm. Which feature on the ECG most strongly supports ventricular tachycardia over SVT with aberrancy?
Answer: AV dissociation visible on the ECG
AV dissociation (P waves marching independently through QRS complexes) is pathognomonic for ventricular tachycardia and cannot occur in SVT.
A patient's ECG shows 'saddle-back' or 'coved' ST elevation in V1-V2 with a right bundle branch block pattern in a patient who has had recurrent syncope. Which syndrome should be suspected?
Answer: Brugada syndrome
Brugada syndrome produces characteristic 'coved-type' ST elevation in V1-V2 with RBBB pattern and is associated with risk of ventricular fibrillation and sudden cardiac death.