Q. What are the Signs of cardiac tamponade?
The clinical presentation will be that of a low output state with anxiety, restlessness, dyspnoea, sweating, cold extremities and drowsiness.
Signs
a) Elevated Jugular venous pressure (JVP)-With the increase in intrapericardial pressure the JVP also gets elevated with prominent ‘X' descent and reduced or absent ‘Y' descent.
b) Tachypnoea.
c) Sinus tachycardia to compensate the low stroke volume.
Pulsus Paradoxus is a Feature of Cardiac Tamponade: Pulsus paradoxus is diagnosed if decline in systolic pressure during normal inspiration exceeds 10 mm. of Hg. (Pulsus paradoxus is an exaggerated normal response). In extreme cases, the pulse may not be felt during inspiration. Though pulsus paradoxus can be detected by palpation of pulse, blood pressure recording during inspiration and expiration and demonstrating the decline of more than 10 mm. of Hg. in systolic pressure during inspiration confirms this physical finding. Mechanism: During inspiration there is increase in systemic venous return to the right side of the heart resulting in greater right ventricular filling. Because of the elevated intra - pericardial pressure in cardiac tamponade, in order to accommodate the extra volume of blood during inspiration in the right ventricle, the interventricular septum is pushed to the left ventricle resulting in reduced left ventricular filling. The decreased pulmonary venus return during inspiration adds on to the reduced left ventricular volume which results in reduced stroke volume and reduced systolic pressure.
Pulsus paradoxus can occur in other conditions like effusive constrictive pericarditis and obstructive pulmonary disease.