In the majority of these conditions, systolic pressure decreases, while diastolic pressure remains normal, leading to a narrow pulse pressure.

In the Postural Orthostatic Tachycardia Syndrome it is postulated that declining venous return reduces stroke volume and frequently results in low pulse pressure. In extreme cases, patients experience a drop in pulse pressure to 0 mm Hg upon standing, rendering them practically pulseless while upright. This condition leads to significant