A 19-year-old college student presents with recurrent episodes of palpitations (HR 180 bpm, BP 110/70 mmHg, RR 20, SpO2 98% on room air). Between episodes, ECG demonstrates a short PR interval and slurred QRS upstroke consistent with ventricular preexcitation. During the acute episode, rhythm strip shows regular narrow-complex tachycardia at 190 bpm. Troponin levels are normal. Which mechanism best explains the tachycardia during this episode?
- A)Triggered activity from delayed afterdepolarizations
- B)Focal atrial automaticity from the pulmonary veins
- C)Antegrade conduction through the AV node and retrograde conduction through the accessory pathwayGABARITO
- D)Antegrade conduction through the accessory pathway and retrograde conduction through the AV node
- E)Reentry entirely within the AV node
Explicação
This patient has Wolff-Parkinson-White syndrome. The most common tachyarrhythmia is orthodromic AV reentrant tachycardia, in which impulses travel antegrade through the AV node and return retrograde through the accessory pathway, producing a narrow-complex tac... Ver explicação completa e trilha adaptativa →