In a suspected stroke case, which cardiac rhythm is most concerning?

• A. Normal sinus rhythm
• B. Atrial fibrillation
• C. Bradycardia
• D. Ventricular tachycardia

Answer: (B)

Atrial fibrillation is particularly concerning in a suspected stroke case due to its association with an increased risk of thromboembolic events. In atrial fibrillation, the atria do not contract effectively, leading to turbulence in blood flow which can result in the formation of clots. These clots can then dislodge and travel to the brain, leading to a stroke.

In contrast, normal sinus rhythm is the standard, healthy heart rhythm that does not contribute to stroke risk. Bradycardia, which refers to an abnormally slow heart rate, may not directly lead to clot formation or strokes, although it can cause other clinical issues. Ventricular tachycardia is a fast heart rhythm originating from the ventricles and generally poses immediate risks to hemodynamics and cardiac output rather than an increased risk for stroke in the same manner as atrial fibrillation.

Thus, in patients with suspected strokes, identifying atrial fibrillation is crucial because it signifies a need for immediate intervention to manage stroke risk, such as anticoagulation therapy to prevent clot formation.