Pulsus alternans is a regular variation in pulse amplitude. It is often associated with impaired ventricular function and is often related to the heart's conduction system.
Pulsus paradoxis is caused by a greater than normal decrease in systolic pressure and pulse wave amplitude during inspiration. It is associated with circumstances in which respiration is labored and often accompanies such conditions as emphysema, pulmonary embolus, cardiac tamponade or lung cancer.
Pulsus bigeminus consists of groups of two beats close together, followed by a longer pause. It is associated with every contraction and is an alternate contraction produced by the extra systolic PVC.
Vibrating pulse is a sharp, jerky pulse associated with lesions of the heart muscle, congestive heart failure, cardiac muscle hypertrophy and resistance to ventricular filling.