What is the workup for cardio-embolic disease?

Workup for Cardio-Embolic Disease

The comprehensive workup for cardio-embolic disease should include cardiac evaluation with electrocardiography, echocardiography, and rhythm monitoring, with transoesophageal echocardiography being superior to transthoracic echocardiography for detecting cardiac sources of embolism. 1

Initial Assessment

Clinical Evaluation

• Assess for suggestive clinical features:
  • Sudden onset of symptoms to maximal deficit
  • Decreased level of consciousness at onset
  • Global aphasia without hemiparesis
  • Co-occurrence of cerebral and systemic emboli
  • Valsalva maneuver at time of symptom onset 2

Cardiac Examination

• Evaluate for:
  • Irregular rhythm (atrial fibrillation)
  • Heart murmurs (valvular disease)
  • Signs of heart failure 1

Diagnostic Testing Algorithm

Step 1: Basic Cardiac Assessment

• 12-lead ECG to detect atrial fibrillation or evidence of MI
• Basic laboratory tests including CBC, comprehensive metabolic panel, and cardiac biomarkers 1

Step 2: Non-invasive Cardiac Imaging

• Transthoracic echocardiography (TTE) with contrast
  • First-line imaging tool for detecting:
    • Left ventricular thrombus
    • Valvular vegetations or dysfunction
    • Reduced ejection fraction
    • Intracardiac masses 1, 3

Step 3: Advanced Cardiac Imaging

• Transesophageal echocardiography (TEE)
  • Superior to TTE for detecting:
    • Left atrial appendage thrombus (sensitivity >90%)
    • Patent foramen ovale and atrial septal aneurysm
    • Valvular vegetations
    • Aortic arch atheroma
    • Left atrial spontaneous contrast 4, 5
  • TEE identifies potential cardiac sources of embolism in 57% of patients with unexplained stroke compared to only 15% by TTE 4

Step 4: Extended Rhythm Monitoring

• Holter monitoring (24-48 hours) for paroxysmal atrial fibrillation
• Consider extended cardiac monitoring (up to 30 days) in cases of cryptogenic stroke 5, 2

Step 5: Additional Imaging (When Indicated)

• Cardiac CT or MRI when:
  • TTE/TEE is inconclusive
  • Better tissue characterization is needed
  • Prosthetic valve thrombosis is suspected
  • Intracardiac tumors require further evaluation 5

Specific Conditions to Evaluate

High-Risk Cardiac Sources

• Atrial fibrillation (most common cause)
• Recent myocardial infarction (especially with EF <29%)
• Mechanical prosthetic valves
• Dilated cardiomyopathy
• Rheumatic mitral stenosis 2, 1

Medium-Risk Cardiac Sources

• Patent foramen ovale with atrial septal aneurysm
• Left ventricular aneurysm
• Left atrial spontaneous echo contrast
• Aortic arch atheroma 5, 3

Important Considerations

Pitfalls to Avoid

• Don't delay treatment of acute limb ischemia for diagnostic testing - treatment should proceed while diagnostic workup continues 1
• Don't miss paroxysmal atrial fibrillation - extended monitoring may be necessary as brief episodes can be missed on standard ECG 2
• Don't rely solely on TTE - TEE has significantly higher diagnostic yield, especially for left atrial appendage thrombi and patent foramen ovale 4
• Don't overlook multiple potential sources - approximately 25% of patients have more than one cardiac source of embolism 5

Prevention Strategies

• For patients with atrial fibrillation, anticoagulation with target INR 2-3 (2-2.5 in elderly patients) is recommended 1
• For patients with mechanical valves, appropriate anticoagulation based on valve type and position 1
• Secondary prevention should be started immediately in high-risk patients without contraindications 2

By following this systematic approach to the workup of cardio-embolic disease, clinicians can identify the source of embolism in the majority of cases and implement appropriate preventive strategies to reduce morbidity and mortality.