Regarding supraventricular tachycardia, what happens to the P wave?

In supraventricular tachycardia (SVT), the heart rate is typically elevated, and this rapid beating can affect the visibility of the P wave on an electrocardiogram (ECG). When SVT occurs, the P waves may be obscured due to the rapid conduction of electrical impulses through the atria and down to the ventricles, which can cause them to become hidden within the QRS complex or the T wave.

This phenomenon happens because the fast rate at which the heart beats can prevent distinct P waves from being formed or detected, leading to their placement being overshadowed. As a result, one may not see P waves explicitly separate from the QRS complex, leading to the conclusion that they are hidden. This characteristic is essential for identifying the presence and type of dysrhythmia associated with SVT.

Other scenarios, like having P waves always visible, being completely absent, or inverted, do not accurately reflect the typical presentation during episodes of SVT, where the primary focus is on the rapid ventricular response and the challenges in distinguishing the P wave within the context of the fast rhythm.