In another variation of the normal venous wave form, seen especially in patients with low heart rates, the systolic collapse, or "x" descent, of the venous pulse is the most easily discernible bedside finding. Note the "h" wave due to gradual passive mid-to-late diastolic filling of the right heart.
Abnormal JVP (giant "a")
You know, once you know the normal physiology of the jugular venous pulse, "a" wave and "v" wave, you can almost predict the pathology. For example, the "a" wave, of course, is due to atrial contraction. Just think about it, it gets a little stretch on it after it fills and then it squeezes, and then there's an impulse up in the neck. Well, now what if that atrium were meeting great resistance, so there's more stretch on that atrium and a bigger contraction? For example, when the right ventricle is all thickened and hypertrophied. Why? Because the pulmonary valve is stenosed. Then the right atrium stretches more as it contracts into the right ventricle, and a giant "a" wave occurs in the neck, and that's what you call it - a big "a" wave in the neck. A giant "a" wave is often seen in pulmonary stenosis.
Let's look again here at the normal impulse, the "a" wave, the "v" wave, the carotid between them undulating gently - the "a" wave dominant. But now let's contrast that to a patient with pulmonary stenosis, and then you see a very big, or giant "a" wave in the neck telling you there's greater resistance, greater contraction, bigger wave in the neck.