The jugular venous pulse in our patient gives us much pathophysiologic information. There is a giant "a" wave just before the carotid arterial impulse. Let's all look together and observe that very large giant "a" wave. [Cut-away]
Our patient has a markedly increased, gigantic "a" wave in the jugular venous pulse, in fact, It is called a giant "a" wave and that enhanced "a" wave is due to increased resistance against which the atrium is pushing during atrial systole. That can be caused by multiple factors. There could be obstruction, for instance, at the tricuspid valve, not very common, but it can occur. There can be hypertrophy of the right ventricle due to some cause, even idiopathic, as in a myopathy, and that also will make it more difficult for the atrium to empty into the right ventricle. There could be obstruction further along at the level of the pulmonary valve, as in pulmonary stenosis, or, and most commonly, there can be pulmonary hypertension that causes right ventricular hypertrophy and still the atrium has trouble getting blood into the right ventricle. And, the net result is that that big wave caused by atrial contraction is seen in the jugular venous pulse as a giant "a" wave.
Normal vs. giant "a" graphics
By comparing the graphic of a normal patient to our patient, we can appreciate that our patient's "a" wave is larger. An abnormally prominent, or giant, "a" wave is due to enhanced right atrial contraction against an increased resistance. This is most often due to an increase in right ventricular diastolic pressure.