Case Presentation:

In our #AMReport at @WCHospital (or #WCHMorningReport), we discussed a case of cardiac tamponade in a patient presenting with new-onset exertional dyspnea and low voltage QRS complexes on ECG. Echocardiography revealed a large malignancy-related pericardial effusion and she required urgent pericardiocentesis.

Dyspnea Image-Based Approach:

Source: Jakubovic 2016

Review of the Wells PE Criteria:

• Use these criteria to determine PE probability
• Scores of <2 indicate low probability; D-dimer prior to additional imaging may be helpful at ruling out VTE in this setting
• Can also use the PERC Rule to determine who is very low risk

Approach to Elevated D-Dimer:

• For VTE: 80-85% sensitive, 93-100% negative predictive value
• Causes of elevated D-Dimer
  • Arterial occlusion (MI, stroke, dissection)
  • VTE (DVT, PE)
  • Systemic disease (beware of false positives): Malignancy, sepsis or infection, pregnancy, trauma etc.

Approach to Low Voltage ECG:

Etiologies of Cardiac Tamponade:

• Acute tamponade: ventricular rupture (secondary to trauma, myocardial infarction or iatrogenic), aortic dissection
• Subacute tamponade:
  • Infection: Viral (HIV), bacterial, TB, Fungal
  • Malignancy: Particularly lung, breast, Hodgkin’s, mesothelioma
  • Inflammatory: SLE, RA, dermatomyositis
  • Post-MI
  • Iatrogenic  or post surgery/procedure
  • Drugs: Hydralazine, procainamide, INH
  • Renal failure (Uremia)
  • Post-radiation
• Three most common causes of moderate-large pericardial effusions: idiopathic, iatrogenic, malignant

Features of Cardiac Tamponade:

Physical Exam

• As per the JAMA Rational Clinical Exam series:
  • Pulsus paradoxus >12mmgHg: +LR 5.6, -LR 0.03
    • >10 mmgHg 82% sensitive, + LR 3.3, -LR 0.03
  • Cardiomegaly on CXR: 89% sensitive
  • Low voltages on ECG: only 42% sensitive

Echo Findings

• Echocardiographic signs suggestive of tamponade include:
  1.  Pericardial effusion
  2. Disatolic RV (high specificity) or RA collapse
  3. IVC dilatation (“plethora”) with minimal respiratory variation (high sensitivity)
     Source: Alerhand & Carter (2019)

Principles of Management of Tamponade:

• Hemodynamic effects warrant urgent intervention
• Temporize with IV fluids to help maintain RV patency
• Transfer to an intensive care setting and pericardiocentesis is the definitive management
• Identify & treat cause

Additional Reading:

1. Roy, CL; Minor, MA; Brookhart, A; Choudhry, N. Does This Patient With a Pericardial Effusion Have Cardiac Tamponade? JAMA. 2007;297(16):1810-1818. doi:10.1001/jama.297.16.1810.
2. Spodick DH. Acute cardiac tamponade. New England Journal of Medicine. 2003 Aug 14;349(7):684-90.