Which condition is indicated by a delta wave in an EKG?

A delta wave on an electrocardiogram (EKG) is a distinctive feature associated with Wolff-Parkinson-White syndrome (WPW). This condition arises due to an accessory pathway that allows electrical signals to bypass the normal conduction route, leading to pre-excitation of the ventricles. The delta wave appears as a slurred upstroke of the QRS complex, indicating that the ventricles are activated earlier than usual due to this abnormal conduction pathway.

Understanding why this is specific to WPW is essential. In WPW, the presence of the delta wave signifies that there is an extra conduction pathway (known as the Bundle of Kent) that connects the atria and ventricles, causing a premature depolarization of the ventricles. This is in contrast to other conditions such as atrial fibrillation, which does not involve the same pre-excitation phenomena, or myocardial infarction, which typically manifests with ST segment changes or abnormal Q waves rather than delta waves. A normal variant does not present any abnormal conduction pathways like WPW does.

Thus, the delta wave is a hallmark of Wolff-Parkinson-White syndrome, making it the correct association in this EKG context.