A nurse is reviewing a cardiac rhythm strip of a client who has atrial flutter.
Which of the following findings should the nurse expect?
A.
Progressively longer PR durations.
B.
Undetectable P waves.
C.
A saw-tooth pattern with an atrial rate of 250 to 400/min.
D.
Absent PR intervals with a ventricular rate of 40 to 60/min.
The Correct Answer and Explanation is:
Correct Answer:
C. A saw-tooth pattern with an atrial rate of 250 to 400/min.
Explanation:
Atrial flutter is a type of supraventricular tachycardia characterized by a rapid and regular atrial rhythm. It is caused by a reentrant circuit within the atria, leading to atrial depolarization at a rate much faster than the ventricles. The hallmark of atrial flutter on a cardiac rhythm strip is a “saw-tooth” pattern, also known as “flutter waves.” This pattern is due to the rapid atrial contractions, which typically occur at a rate between 250 to 400 beats per minute.
Option C describes this saw-tooth pattern and is the correct answer. The flutter waves appear as multiple, regular, and uniform atrial deflections between the QRS complexes. The ventricular rate, however, is often slower because the atrioventricular (AV) node cannot conduct all the atrial impulses to the ventricles, typically resulting in a 2:1 or 4:1 conduction ratio.
Option A refers to progressively longer PR durations, which are characteristic of a second-degree AV block type I (Wenckebach), not atrial flutter. In this condition, the PR interval lengthens progressively until a QRS complex is dropped. This finding is not associated with atrial flutter.
Option B mentions undetectable P waves, which is more indicative of atrial fibrillation, another type of atrial arrhythmia where the atria quiver chaotically, leading to an irregular and often rapid ventricular rate. In atrial fibrillation, P waves are absent because of the disorganized atrial activity, but this is not the case in atrial flutter.
Option D suggests absent PR intervals with a ventricular rate of 40 to 60 beats per minute, which is more typical of a junctional rhythm. In a junctional rhythm, the impulse originates in the AV junction rather than the atria, resulting in absent or inverted P waves and a slower ventricular rate, but this is not related to atrial flutter.
Understanding these distinctions is crucial for accurate diagnosis and management of different cardiac arrhythmias. Atrial flutter is significant because it can lead to symptoms like palpitations, shortness of breath, and increased risk of stroke due to thrombus formation in the atria. Prompt recognition and appropriate treatment, such as rate control, rhythm conversion, or anticoagulation, are essential in managing this condition effectively.