do you mean kussmaul sign? or perhaps kussmaul breathing of DKA? There are no kussmaul sounds- I see that is a typo but its important to keep things straight as there are two separate kussmauls
Furthermore your question is most certainly beyond the scope of the USMLE- but there are a few important learning points to make.
First- constrictive pericarditis is a result of fibrosis and hardening of the pericardium. This prevents any respiratory influence unlike that seen in tampoande. Importantly, the effects of blood entry into the right V will not have the same impact on the left V- that is, pulsus paradoxus is not to be expected in CP- this is because the heart is able to expand to teh size of the pericardium without th eneed to shift blood into the IV septum as seen in tamponade.
Finally, even though respirations effects are not there on the heart in CP speifically inspiration- there is effect in the pulmonary veins because they are outside teh pericardium. As a result the pulm veins expand and draw blood into the heart- this drawing of blood leads to the increase in early diastolic volume that you see- and the resulting decline in y- I hope you understand why the y declines - because it is jugular venous pressure- thus more blood enters the right heart - so the y drops during EARLY diastolic filling. To clarify- what I mean is this- blood travels even more from the veins into the RA- thus blood from the jugular vein for example will be leaving faster- leading to the greater 'y' decline- and an increased RA increase (increased early diastolic filling)
Why is there a distinction bw early and late? because early is about passive filling due to the just opened ventricles- this draws blood through the atria. Late diastolic filling is due to the contraction of the atria.
Anyway- in tamponade there is fluid pushing down on the percardium and preventing expansion of any sort- thus blood is compressed from enterinjg the heart as much- however, during inspiration there is a decrease in venous pressure drawing blood in- the compressed heart (which cannot even enlarge to the size of the pericardium) pushes blood into the IV septum causing pressure drop in LV- this leads to some backflow and pushes blood back into the RA- and the resulting increase in pressure is seen as a kussmaul sign and increased JVD
