When should an echocardiogram be ordered?

When to Order an Echocardiogram

Echocardiography should be ordered when there is clinical evidence of structural heart disease, hemodynamic instability, or specific cardiac symptoms that require diagnostic confirmation—not as a routine screening test in asymptomatic patients with normal cardiovascular examinations. 1

Class I Indications (Definitely Appropriate)

Acute/Emergency Settings

Hemodynamic instability of any cause warrants immediate echocardiography, particularly when cardiac tamponade, acute valvular dysfunction, or ventricular dysfunction is suspected. 1

• Cardiac arrest or cardiogenic shock: Perform echocardiography immediately following 12-lead ECG in patients with hemodynamic instability of presumed cardiovascular origin 1
• Acute chest trauma: Order for serious blunt or penetrating chest trauma with suspected pericardial effusion, tamponade, or aortic injury 1
• Suspected aortic dissection: TEE is the procedure of choice and should be performed emergently 1
• Acute coronary syndrome with high-risk features: Order immediately in patients presenting with heart failure, shock, or new cardiac murmur 1, 2

Chest Pain Evaluation

Order echocardiography for chest pain when there is clinical evidence of valvular disease, pericardial disease, or structural heart abnormalities—not for uncomplicated chest pain without these features. 1

• Class I: Chest pain with clinical evidence of valvular or pericardial disease 1
• Class II: Known or suspected coronary artery disease (though majority will have normal resting echocardiograms) 1
• Class III (inappropriate): Noncardiac chest pain without clinical evidence of heart disease 1

Post-Myocardial Infarction

Perform transthoracic echocardiography within 24-48 hours after myocardial infarction to establish baseline left ventricular function, identify mechanical complications, and detect mural thrombus. 2

• For uncomplicated MI: Day 2-3 of hospitalization 2
• For patients undergoing primary PCI: Within 24-48 hours post-procedure 2
• Critical follow-up: Repeat echocardiogram ≥40 days after discharge in patients with initially reduced LVEF who may be candidates for ICD therapy 2

Cardiac Murmurs

Order echocardiography for cardiac murmurs accompanied by symptoms or signs of cardiac disease—not for all murmurs. 1

• Acute care patients with murmurs plus: heart failure, myocardial ischemia/infarction, syncope, thromboembolism, infective endocarditis, or abnormal ECG 1
• Critical aortic stenosis with cardiogenic shock: Assess suitability for balloon aortic valvuloplasty 1
• Severe mitral stenosis with cardiogenic shock/pulmonary edema: Assess for percutaneous mitral commissurotomy 1

Dyspnea

Order for dyspnea when heart failure, valvular disease, or pulmonary hypertension is clinically suspected. 3

• Class I: Dyspnea with abnormal cardiac examination findings, suspected heart failure, or valvular symptoms 3
• Class III (inappropriate): Dyspnea without clinical evidence of heart disease, pulmonary hypertension, or significant lung disease 1

Trauma Patients

Order immediately for mechanically ventilated trauma patients or those with unexplained hypotension after injury. 1

• Hemodynamically unstable multiple-injury patients with mechanism suggesting cardiac/aortic injury (deceleration or crush) 1
• Widening of mediastinum post-injury (use TEE for suspected aortic injury) 1
• Potential catheter, guidewire, or pericardiocentesis needle injury 1

Class II Indications (May Be Appropriate)

• Known or suspected coronary artery disease presenting with chest pain 1
• Follow-up studies in victims of serious trauma 1
• Evaluation of hemodynamics in trauma patients when pulmonary artery catheter data is disparate with clinical situation 1

Class III Indications (Inappropriate - Should NOT Order)

Do not order echocardiography as a screening test in asymptomatic patients with normal cardiovascular examinations. 1, 3

• Noncardiac chest pain 1
• Dyspnea without clinical evidence of heart disease 1
• Hyperventilation syndrome 1
• Suspected myocardial contusion in hemodynamically stable patients with normal ECG 1
• Patients with stable vital signs, no murmurs, and no signs of heart failure 3
• Asymmetric lower extremity edema without cardiac symptoms: Consider duplex ultrasound for venous insufficiency instead 3

Special Populations

Congenital Heart Disease

• Clinically suspected congenital heart disease with murmur, cyanosis, unexplained arterial desaturation, and abnormal ECG/radiograph 1
• Known congenital heart disease with change in clinical findings 1
• Periodic follow-up for specific lesions requiring monitoring of ventricular function and AV valve regurgitation 1

Post-Procedural Complications

• Hemodynamic instability following cardiac surgery or catheter laboratory intervention 1
• Suspected pericardial collection or cardiac tamponade post-cardiac surgery 1

Critical Pitfalls to Avoid

• Never delay echocardiography beyond 48 hours in acute MI, as this may miss early mechanical complications 2
• Do not rely solely on initial echocardiography without follow-up in patients with LV dysfunction 2
• Do not use echocardiography to replace cardiovascular examination—the basic cardiovascular evaluation remains the most appropriate screening method 1
• Do not order for reassurance alone in asymptomatic patients with normal examinations 1, 3
• TEE is relatively contraindicated in patients with cervical spine fractures 1

When TEE is Superior to TTE

Use transesophageal echocardiography when: 1

• Hemodynamically unstable patient with suboptimal TTE images
• Mechanically ventilated patients
• Major trauma or postoperative patients unable to be positioned for adequate TTE
• Suspected aortic dissection or aortic injury
• Evaluation of prosthetic valves or endocarditis when TTE is inconclusive