Square root sign vs prominent y descent in JVP

Though square root sign can be seen in constrictive pericarditis, right ventricular myocardial infarction and restrictive cardiomyopathy, a prominent y descent is not seen in the latter two conditions. This is thought to be due to the abnormal relaxation of the right ventricular myocardium in right ventricular myocardial infarction and restictive cardiomyopathy.