A patient in the ICU reports worsening shortness of breath. Does this subxiphoid view echocardiogram suggest cardiac tamponade as the etiology of the complaint?
#Cardiac tamponade physiology on echocardiogram can be difficult to distinguish from just a moderate to large pericardial effusion
#This is all about ultrasound, so forget about those ‘clinical signs’ like hypotension, distant heart sounds, pulsus paradoxus, and visible JVD. A sonographic finding with strong specificity for cardiac tamponade is right ventricular wall collapse during DIASTOLE
#Check out this slightly dizzying image showing how M-mode can be used to draw a line through the RV free wall, septal wall, and mitral valve to record their motion in real time
#Remember that Diastole is when the mitral valve is OPENING toward the septum
#The RV free wall collapses appropriately during the END of Systole, which is the moment of maximum endocardial contraction
#The RV wall then expands outward during Diastole. In tamponade, this wall would collapse during Diastole due to the high pressure of a pericardial effusion. Therefore this echocardiogram does NOT show tamponade (womp womp, major letdown, but certainly better for the patient). Beware of patients with a known history of pulmonary hypertension and/or RV failure as they will likely have thick RV walls, which will complicate the sonographic evaluation.
Singh S, Wann LS, Schuchard GH, Klopfenstein HS, Leimgruber PP, Keelan MH, Brooks HL. Right ventricular and right atrial collapse in patients with cardiac tamponade–a combined echocardiographic and hemodynamic study. Circulation. 1984 Dec 1;70(6):966-71.
Schiller NB, Botvinick EH. Right ventricular compression as a sign of cardiac tamponade: an analysis of echocardiographic ventricular dimensions and their clinical implications. Circulation. 1977 Nov 1;56(5):774-9.