NORCET 6 Prelims -2024: Identify the ECG given below:

NORCET 6 Prelims -2024

Medical & Surgical Nursing

Medium

Appeared in: NORCET 6 Prelims -2024

Explanation

The ECG demonstrates a regular rhythm with a rapid atrial rate, which is characteristic of Atrial Flutter.
The baseline shows distinct 'sawtooth' flutter waves (F waves), which replace normal P waves. This is the hallmark sign of Atrial Flutter.
The QRS complexes are narrow, indicating a supraventricular origin of the rhythm.
The ventricular rate is slower than the atrial rate due to the AV node blocking some of the rapid atrial impulses (e.g., a 2:1 or 3:1 block).

Option B: Atrial Fibrillation is characterized by an irregularly irregular rhythm and a chaotic baseline with no discernible P waves or organized flutter waves. The provided ECG has a regular rhythm and clear sawtooth waves.
Option C: Sinus Tachycardia requires the presence of a normal P wave preceding every QRS complex, indicating the impulse originates from the sinus node. The ECG in the image lacks normal P waves and instead shows flutter waves.
Option D: Normal Sinus Rhythm has a rate between 60-100 bpm and normal P waves. The ECG shows a rate faster than 100 bpm and lacks normal P waves.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain ECG interpretation of supraventricular tachyarrhythmias as background academic context rather than a clinical decision trigger.
Atrial flutter is a clinically significant arrhythmia because the rapid atrial rate can lead to a rapid ventricular response, causing symptoms like palpitations, shortness of breath, and dizziness.
A major risk associated with atrial flutter (similar to atrial fibrillation) is the formation of blood clots in the atria, which can travel to the brain and cause a stroke. Therefore, anticoagulation is a key part of management.
Nursing interventions include monitoring the patient's heart rate and rhythm, assessing for signs of decreased cardiac output (like hypotension or altered mental status), and preparing for potential interventions like cardioversion or administration of rate-controlling medications.

How to Approach the Question

First, assess the overall rhythm. Look at the R-R intervals (the distance between the peaks of the QRS complexes). In this ECG, they appear regular.
Next, determine the heart rate. A quick estimation can be made. If the rhythm is regular, the rate is approximately 150 bpm if there are two large squares between QRS complexes, and 100 bpm if there are three. Here, it's faster than 100 bpm, indicating a tachycardia.
Then, carefully examine the baseline for P waves. Look in the space between the T wave of one beat and the QRS of the next. In this strip, you will not find normal, rounded P waves.
Instead of P waves, identify the abnormal waveform on the baseline. Notice the repetitive, sharp, 'sawtooth' or 'picket fence' appearance. This is the classic sign of atrial flutter waves (F waves).
Finally, combine these findings: a regular, tachycardic rhythm with sawtooth flutter waves instead of P waves. This combination confirms the diagnosis of Atrial Flutter.

Concept Tested & Keywords

Concept Tested: ECG interpretation of supraventricular tachyarrhythmias.
Stem keywords: ECG, identify, Lead II
Lead-in keywords: Identify
Clinical cues: The 'sawtooth' baseline is the classic pathognomonic sign for Atrial Flutter.

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E6 Medicine Harrison 22e Part 1 pp. 1984-1986, 1985-1987

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