Which of the following hemodynamic changes is not evident in cardiac tamponade during diastole?
Ans. is 'c' i.e., Biphasic venous return Hemodynamics of cardiac Tamponade inDiastole* During the diastole the pericardial pressure remains elevated.* It is greater than the intracavitary pressure thus there is no filling during the diastole.* The absence of venous return during the diastole leads to absence of "y" waves on the /. V.P. and the "diastolic collapse" of the right atria and ventricle.Systole* During systole, the decrease in size of the heart due to ventricular contraction reduces the pericardial pressure.* Thus in cardiac tamponade heart filling occurs only in systole.* So, the venous return in cardiac tamponade is unimodal instead of the normal biphasic mode.* The ventricular contraction causes the atria to relax and produce the "x" wave of the J.V.P.
Right atrial and ventricular collapse
Absent y wave on JVP
Biphasic venous return
Elevated pericardial pressure
C.V.S.