A 48-year-old man has recurrent palpitations. ECG shows a regular narrow-complex tachycardia at 150 bpm with inverted sawtooth flutter waves best seen in leads II, III, and aVF. Which intervention offers definitive cure?
- A Catheter ablation of the cavotricuspid isthmus ✓
- B Pulmonary vein isolation
- C AV node modification with slow pathway ablation
- D Lifelong flecainide therapy
Correct answer: A. Catheter ablation of the cavotricuspid isthmus
Explanation
Typical atrial flutter is a macro-reentrant circuit around the tricuspid annulus dependent on the cavotricuspid isthmus. The atrial rate is about 300/min, commonly conducting 2:1 to give a ventricular rate of 150. Radiofrequency ablation creating a linear lesion across the cavotricuspid isthmus blocks the circuit and achieves cure rates above 90 percent. Pulmonary vein isolation treats AF, not flutter, and flecainide must never be used alone in flutter because it can slow the flutter rate enough to allow 1:1 AV conduction.
Reference: Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 12th ed.
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Written and medically reviewed by the StethoPrep medical team.