The key elements of the bifid pulse are the brisk upstroke, bifid peak and large amplitude.

The brisk upstroke and first peak of the bifid arterial pulse are related to an increased initial velocity of left ventricular contraction. This, in turn, is related to an increased preload due to excess volume and a decreased afterload due to peripheral vasodilatation.

The second peak is likely caused by reflected waves from the periphery that are accentuated by a large stroke volume associated with a decreased peripheral vascular resistance. This wave is due to an exaggeration of the normal flow reversal in the aorta.

Following the second peak, there is a rapid fall in pressure during late systole - the so-called "systolic collapse". This is, in part, related to the rapid runoff of blood into dilated peripheral vessels.

The combination of a bifid arterial pulse with a brisk upstroke and wide pulse pressure is most consistent with aortic regurgitation. A bifid arterial pulse may also be seen in combined aortic regurgitation and stenosis, in hypertrophic obstructive cardiomyopathy, in severe patent ductus arteriosus and very rarely, with fever or exercise.