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ECG Findings

  • Tachycardia with a wide monomorphic QRS complex.

  • Ventricular rate may be very rapid (300 bpm).

  • Sine wave appearance with regular large oscillations.


  1. Imagine an atrial flutter sawtooth with much larger amplitude.

  2. When you see a very rapid wide-complex tachycardia (> 240 bpm), consider ventricular flutter or WPW with atrial fibrillation or flutter.

  3. WPW with atrial flutter may be indistinguishable from ventricular flutter.

  4. Ventricular flutter is treated as VT and usually leads to ventricular fibrillation if not promptly corrected with antiarrhythmic medications or electrical cardioversion.

  5. Patients with such a rapid rate are almost always unstable. Emergent cardioversion is indicated. If the patient appears to be stable enough for chemical cardioversion, choose a medication that is safe to use with WPW, such as procainamide or amiodarone.


Ventricular Flutter. (ECG contributor: James V. Ritchie, MD.)


Very rapid, regular, wide-complex tachycardia with sine wave appearance. The rate in this example is 330 bpm. Differential diagnosis includes WPW with atrial flutter.

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