This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2019, Subject name: Medicine
Deep y descent in JVP is seen in all except:- 
Select and explain. 
A. Cardiac tamponade, B. RCM, C. Constrictive pericarditis, D. Tricuspid regurgitation
A: Cardiac tamponade
Answer: A: Cardiac tamponade 
Explanation: Option A- Cardiac tamponade- y descent absent as hea can't relax Bag of fluid squeezing hea from outside passive filling of blood in the ventricle. Option D- Tricuspid regurgitation CV wave -feature of severe TR as CV wave is positive. Step y descent Steep x & Step Y causes= Constrictive pericarditis Restrictive cardiomyopathy Rapid ventricular filling || d/t Calcification outside hea Fibrosis of hea( Diastasis impaired) Step x absent Y = in cardiac tamponade | As no relaxation Option B- shows steep y Option C- shows steep y