Cardiac Tamponade

1. Definitions
   1. Compression of heart by fluid in pericardial sac
2. 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 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
3. Causes
   1. See Pericardial Effusion
4. Symptoms
   1. Common
      1. Dyspnea
      2. Fatigue
   2. Other symptoms
      1. Orthopnea
      2. Chest Pain
      3. Syncope
5. Signs
   1. Classic presentation (Beck's Triad)
      1. Hypotension
      2. Narrow Pulse Pressure
      3. Quiet 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
6. Imaging: Chest XRay
   1. Enlarged cardiac shadow: Globular appearance
7. Diagnostics
   1. Echocardiogram (preferred study)
      1. Focused Assessment with Sonography for Trauma (FAST)
   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
8. Diagnosis
   1. Pulsus Paradoxus with Pericardial Effusion confirms diagnosis
9. Differential Diagnosis: Shock states
   1. Myocardial Infarction
   2. Septic shock
   3. Pulmonary Embolism
10. Management: Emergent (e.g. trauma)
    1. Immediate pericardiocentesis under Ultrasound guidance
       1. Sub-xiphoid approach
       2. Needle angled toward left Shoulder
       3. Constant suction applied to syringe on entry
       4. Send fluid for cytology if not traumatic in origin
    2. Emergent Cardiothoracic surgery
       1. Pericardial window placement and other definitive management
    3. Intravenous fluids
       1. Transient stabilization to increase venous pressure
11. Management: Malignancy specific
    1. Consider reaccumulation prevention (post-stabilization)
       1. Chemotherapy
       2. Radiation
       3. Sclerosis