Cardiac Tamponade

Overview

Pathophysiology

  • Increase in pericardial pressure leads to a decrease in preload
  • As right-sided pressures increase the intraventricular septum moves into the left ventricle decreasing cardiac output

The size of the pericardial effusion is not as important as the rate of fluid accumulation within the pericardium.

Causes

Many potential causes including autoimmune conditions, infection (viral and bacterial), myocarditis, and malignancies.

The two causes to always consider first. Management requires surgical repair.

  • Aortic Dissection
  • Ventricular free wall rupture (examples: post-MI or after pacemaker placement)

Diagnosis

  • Bedside ultrasound is vital in establishing the diagnosis (see video below)
  • IVC with greater 50% collapse is around 97% sensitive for ruling out the diagnosis
  • Pulsus paradoxus, physical exam, and electrical alternansĀ are not reliable in the diagnosis of pericardial tamponade

Management

Definitive Management

  • Definitive management is drainage (see video above)
  • For hemopericardium surgical repair is necessary

Hemodynamic SupportĀ 

  • Small fluid bolus staring at 500cc
  • If right ventricular pressures are elevated, then a fluid bolus may decrease cardiac output by causing septal shift into the left ventricle (assess patient’s response to fluid bolus)
  • Norepinephrine for further hemodynamic support
  • Try to avoid dobutamine, epinephrine, and dopamine since they tend to have a greater effect on HR and will decrease diastolic filling time

Emergency Medicine Foam

EM@3AM – Cardiac Tamponade