Becks triad is seen in
Components of Beck's Triad Hypotension with a Narrowed Pulse Pressure Jugular Venous Distention Muffled hea Sounds it is a pathognomic feature of cardiac tamponade Ref Harrison 20th edition pg 1546
Constrictive pericarditis
Restrictive cardiomyopathy
Cardiac tamponade
HOCM
C.V.S