Cardiac Tamponade

1. See Also
   1. Pericardial Effusion
   2. Pericarditis
   3. Echocardiogram
   4. Emergency Pericardiocentesis
   5. Oncologic Emergency
2. Definitions
   1. Cardiac Tamponade
      1. Compression of heart by fluid in pericardial sac resulting in hemodynamic instability
3. Pathophysiology
   1. Physiologic effects of effusion vary by timing
      1. Gradual accumulation is accomodated by sack stretch (up to 250 ml)
      2. Rapid accumulation results in more abrupt hemodynamic compromise
   2. Cardiac Tamponade pathway
      1. Effusion prevents diastolic relaxation of ventricles
      2. Right Ventricular Filling Pressure approaches left ventricular pressure
         1. Loss of normal pressure differentials prevents diastolic filling of heart
4. Causes
   1. See Pericardial Effusion
5. Symptoms
   1. Common
      1. Dyspnea
      2. Fatigue
   2. Other symptoms
      1. Orthopnea
      2. Chest Pain
      3. Syncope
6. Signs
   1. Classic presentation (Beck's Triad)
      1. Hypotension
      2. Narrow Pulse Pressure
      3. Quiet or muffled heart sounds
   2. Cardiac exam
      1. Distended neck veins (Jugular Venous Distention)
         1. Increased Central Venous Pressure (CVP)
      2. Hyperdynamic JVP waveform (exaggerated X descent)
      3. Pulsus Paradoxus (pathognomonic for Pericardial Effusion)
      4. Faint heart sounds
      5. Friction rub
   3. Cardiopulmonary Shock
      1. Kussmaul's Sign
      2. Cold clammy skin
      3. Tachycardia
      4. Falling arterial pressure
         1. Narrow Pulse Pressure
         2. Hypotension
      5. Cyanosis
7. Imaging: Chest XRay
   1. Enlarged cardiac shadow: Globular appearance
8. Diagnostics
   1. Echocardiogram (preferred study)
      1. Focused Assessment with Sonography for Trauma (FAST)
      2. See Pericardial Effusion
      3. Right heart wall movement appears as a paradoxical rocking motion
         1. Right atrium collapse in systole (also occurs with Hypovolemic Shock)
         2. Right ventricular collapse of free wall in diastole (despite tricuspid valve opening, and RV filling)
      4. Inferior Vena Cava
         1. Does not collapse during inspiration when Cardiac Tamponade is present
   2. Electrocardiogram
      1. Low voltage complexes
      2. Electrical alternans may be present
      3. Untreated, Pulseless Electrical Activity (PEA) may result
   3. Cardiac catheterization: Right-Left pressures equal
      1. Right ventricular diastolic pressure
      2. Pulmonary capillary wedge pressure
9. Diagnosis
   1. Bedside Ultrasound (see Echocardiogram above)
      1. Consider Bedside Ultrasound in all patients with Tachypnea, Shortness of Breath or Tachycardia
      2. Beck's Triad has low sensitivity (not all Cardiac Tamponade patients have Hypotension)
   2. Pulsus Paradoxus with Pericardial Effusion confirms diagnosis
10. Differential Diagnosis: Shock states
    1. Myocardial Infarction
    2. Septic Shock
    3. Pulmonary Embolism
11. Management: Emergent
    1. Immediate Pericardiocentesis under Ultrasound guidance (ATLS)
       1. See Emergency Pericardiocentesis
       2. Hypoperfusion with Cardiac Tamponade is an indication for Pericardiocentesis
       3. Sub-xiphoid approach with needle angled toward left Shoulder
       4. Parasternal approach has been advocated due to clear path to Pericardium
       5. Constant suction applied to syringe on entry
       6. Send fluid for cytology if not Traumatic in origin
    2. Emergency Thoracotomy
       1. Indicated in Cardiac Tamponade due to Trauma (esp penetrating), refractory to Pericardiocentesis
    3. Emergent Cardiothoracic surgery
       1. Pericardial window placement and other definitive management
    4. Intravenous Fluids
       1. Transient stabilization to increase venous pressure
       2. Norepinephrine may also be used to transiently improve perfusion
    5. Precautions
       1. Avoid Positive Pressure Ventilation until after decompression with Pericardiocentesis
          1. Negative intrathoracic pressure is the last safeguard maintaining venous return in Pericardial Tamponade
          2. Positive Pressure Ventilation eliminates negative intrathoracic pressure
          3. Pulseless Electrical Activity arrest (PEA arrest) results
       2. Avoid measures that reduce cardiac filling
          1. Avoid inotropes (increased Heart Rate decreases filling time)
       3. References
          1. Mallemat and Swadron in Herbert (2013) EM:Rap 13(12): 10-11
12. Management: Malignancy specific
    1. Consider reaccumulation prevention (post-stabilization)
       1. Chemotherapy
       2. Radiation
       3. Sclerosis