Atrial Fibrillation Rate: Atrial rate usually > 400, Ventricular rate variable Rhythm: Atrial and ventricular very irregular P waves: No identifiable P waves, Erratic, wavy baseline PRI: None QRS: Usually <.10 Rapid impulses originating in multiple sites in the atria cause the atrium itself to "quiver". This is ineffective in allowing for an effective atrial kick. The AV node protects the patient from having too high a ventricular response, and blocks the majority of the impulses.
