Paramedic National Registry Practice

In a patient with a history of Wolff-Parkinson-White syndrome experiencing a flutter in the chest, what is the likely pathophysiology?

1. Myocardial ischemia

2. Atrial fibrillation

3. Ventricular irritability

4. Electrical conduction block

The correct answer is: Ventricular irritability

In a patient with Wolff-Parkinson-White (WPW) syndrome, the underlying issue is related to the presence of an accessory pathway that can conduct electrical impulses faster than the normal conduction system of the heart. This condition predisposes the patient to certain types of arrhythmias. The fluttering sensation in the chest is commonly associated with episodes of tachycardia that can occur due to reentrant circuits formed by the combination of the normal conduction pathways and the accessory pathway. When these circuits become active, they can lead to rapid atrial contractions, and subsequently, if the impulses reach the ventricles, they can cause increased ventricular irritability as the heart attempts to maintain an appropriate rhythm despite the abnormal conduction. In this scenario, the correct answer highlights that the immediate pathophysiology relates to the local depolarization of the ventricles, which is referred to as ventricular irritability. This is a direct consequence of the rapid electrical activity caused by the reentrant pathways associated with WPW syndrome, leading to the characteristic symptoms experienced by the patient.