A 55-year-old woman with mitral stenosis presents with dyspnea and palpitations; which tachyarrhythmia is most likely on EKG?

• A. Ventricular tachycardia
• B. Atrial flutter
• C. Ventricular fibrillation
• D. Ventricular bigeminy

Answer: (B)

Mitral stenosis creates chronic pressure and volume changes that enlarge the left atrium, setting the stage for chaotic atrial electrical activity. This makes atrial fibrillation the most common tachyarrhythmia seen with mitral stenosis. On EKG you’d expect an irregularly irregular rhythm with no distinct P waves and a variable, often rapid, ventricular response. Atrial flutter can occur but is less typical in this setting and would show regular flutter waves in a sawtooth pattern rather than the disorganized baseline of AF. The presenting symptoms of dyspnea and palpitations fit AF with rapid ventricular response, which also carries a high risk of thromboembolism in mitral stenosis. Management emphasizes rate control and anticoagulation to reduce stroke risk while addressing the underlying hemodynamic impact.