What are the indications for an echocardiogram (echo) in the emergency room?

Indications for Echocardiography in the Emergency Room

Emergency echocardiography is indicated for patients presenting with acute chest pain, dyspnea, hemodynamic instability, or trauma when cardiac pathology is suspected or needs to be excluded. 1

Key Clinical Presentations Requiring Emergency Echocardiography

Acute Chest Pain

• Suspected myocardial ischemia/infarction with non-diagnostic ECG and cardiac enzymes, especially when pain is ongoing 1
• Known underlying cardiac disease (valvular, pericardial, or primary myocardial)
• Hemodynamic instability unresponsive to initial treatment
• Suspected acute aortic syndromes, pulmonary embolism, myopericarditis, or Takotsubo cardiomyopathy
• Suspected pericardial disease including effusion or tamponade 1

Acute Dyspnea

• Distinguishing cardiac vs. non-cardiac etiology when clinical and laboratory findings are ambiguous
• Assessment of left ventricular function in suspected heart failure
• Detection of acute valvular regurgitation or prosthetic valve dysfunction
• Detection of complications of myocardial infarction (acute mitral regurgitation, ventricular septal defect, free-wall rupture) 1

Hemodynamic Instability/Shock

• Differential diagnosis of hypotension or shock
• Rapid identification of pericardial effusion and tamponade
• Assessment of ventricular function and volume status
• Evaluation of valvular pathology 1

Trauma

• Serious blunt or penetrating chest trauma with suspected pericardial effusion or tamponade 1
• Mechanically ventilated multiple-trauma patients 1
• Hemodynamically unstable multiple-injury patients with potential cardiac or aortic injury 1
• Suspected aortic injury with widened mediastinum 1
• Suspected catheter, guidewire, or pericardiocentesis needle injury 1

Specific Pathologies Where Echo Is Critical

Cardiac Tamponade

• Identification of pericardial effusion
• Assessment of hemodynamic impact:
  • Diastolic right ventricular collapse (high specificity)
  • Systolic right atrial collapse (earliest sign)
  • Plethoric inferior vena cava with minimal respiratory variation
  • Exaggerated respiratory variations in valve inflow velocities 2

Acute Aortic Syndromes

• Initial imaging modality for suspected aortic dissection
• Transesophageal echocardiography (TEE) is superior for thoracic aortic assessment 1

Complications of Myocardial Infarction

• Ventricular septal defect
• Papillary muscle rupture with acute mitral regurgitation
• Free wall rupture and tamponade
• Left ventricular thrombus formation 3

Post-Procedural Complications

• Pericardial effusion after cardiac surgery or interventional procedures
• Prosthetic valve dysfunction
• Device malposition 1

When Echocardiography Is NOT Recommended

• Chest pain when non-cardiac etiology is apparent
• Chest pain in patients with confirmed diagnosis of myocardial infarction
• As primary diagnostic tool for pulmonary embolism in hemodynamically stable patients
• Minor chest injuries without concerning symptoms or signs 1
• As a routine procedure during cardiopulmonary resuscitation 1

Choice of Echocardiographic Technique

Transthoracic Echocardiography (TTE)

• First-line approach for most emergency situations
• Focused cardiac ultrasound can be performed rapidly at bedside

Transesophageal Echocardiography (TEE)

• When TTE images are suboptimal (mechanical ventilation, obesity, chest deformity)
• For better visualization of specific structures:
  • Thoracic aorta for dissection
  • Prosthetic valves
  • Left atrial appendage for thrombus
  • Suspected endocarditis 1
• Relatively contraindicated in patients with cervical spine fractures 1

Contrast Echocardiography

• Improves endocardial visualization for assessment of ventricular function
• Helps in detection of left ventricular thrombus
• May facilitate diagnosis of aortic dissection 1

Implementation Considerations

• 24-hour availability of a physician with competence in emergency echocardiography
• Efficient consultative service for special echocardiographic techniques
• Team approach with supervision by experts in echocardiography
• Quality control and continuous education 1

Emergency echocardiography should follow the "ABCD approach": Awareness (think beyond apparent explanations), Be suspicious (referral diagnosis may be misleading), Comprehensiveness (complete examination as suitable), and Double R (record and review) 1.