Which rhythm is associated with a very rapid rate that can lead to congestive heart failure or myocardial ischemia and carries a risk of pulmonary and cerebral emboli?

• A. Atrial Tachycardia
• B. Atrial Flutter
• C. Atrial Fibrillation
• D. Junctional Escape Rhythm

Answer: (B)

Atrial flutter is a very fast, organized atrial rhythm that fits this description. The atrial rate is typically around 250–350 beats per minute, and the ventricular response is often a regular 1:2 conduction, yielding about 150 bpm. That intense, rapid atrial activity shortens diastolic filling time, reducing stroke volume and potentially triggering congestive heart failure or myocardial ischemia, especially in patients with underlying heart disease.

The organized, sawtooth flutter waves reflect the regular atrial impulses, and the rapid rate means blood can pool in the atria, forming thrombi. These clots can embolize to the brain, causing stroke, or, if a right-sided thrombus is involved, to the lungs, causing pulmonary embolism. This combination of a rapid rate with embolic risk is how atrial flutter typically presents.

This differs from atrial tachycardia, which usually has a slower, less regular atrial rate; atrial fibrillation, while also embolic and hemodynamically concerning, features irregularly irregular rhythm with no distinct P waves, rather than the regular sawtooth pattern. Junctional escape rhythm is slower and does not produce the rapid, organized atrial activity described here.