This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
Cardiac tamponade causes pulsus: 
Select and explain. 
A. Alternans, B. Bigemini, C. Paradoxus, D. Parvus
C: Paradoxus
Answer: C: Paradoxus 
Explanation: Ans: c (Paradoxus) Ref: Harrisons, 16th ed, p. 1416; 17th ed, p. 1491Clinical signs in cardiac tamponade - pulsus paradoxus, prominent x descent in JVPECG changes - low ECG voltage, electrical alternans. RVDC feature in echoNotesFreidrichs sign - Rapid fall (steep Y descent) and rise of JVP seen in constrictive pericarditis and tricuspid regurgitation.