Can Brugada syndrome be diagnosed with echocardiography (echo)?

Brugada Syndrome Cannot Be Diagnosed with Echocardiography

Brugada syndrome cannot be diagnosed with echocardiography as it requires specific electrocardiographic (ECG) criteria and is characterized by the absence of structural heart disease. 1, 2

Diagnostic Criteria for Brugada Syndrome

Brugada syndrome is diagnosed based on characteristic ECG patterns, specifically:

• Type 1 (diagnostic) pattern: Coved ST-segment elevation ≥2mm followed by negative T-wave in leads V1-V3 2
• Type 2 pattern: "Saddle-back" morphology with high takeoff ST-segment elevation
• Type 3 pattern: Either coved or saddleback morphology with J point elevation ≤2mm 1

Only the Type 1 pattern is considered diagnostic for Brugada syndrome. Types 2 and 3 are suspicious but require conversion to Type 1 pattern (either spontaneously or with sodium channel blocker challenge) to confirm diagnosis 1, 2.

Role of Echocardiography in Brugada Syndrome

Echocardiography serves a different purpose in the Brugada syndrome diagnostic pathway:

• To exclude structural heart disease: Brugada syndrome is defined as a primary electrical disorder occurring in the absence of structural heart disease 1, 2
• Not diagnostic: Echocardiography typically shows normal cardiac structure and function in true Brugada syndrome 3

Correct Diagnostic Approach

The proper diagnostic approach for Brugada syndrome includes:

1. 12-lead ECG examination: Focusing on right precordial leads (V1-V3) for characteristic patterns 2
2. High precordial lead ECG: If standard ECG is non-diagnostic but Brugada syndrome is suspected, ECG with leads V1 and V2 placed in the 2nd or 3rd intercostal space may reveal the pattern 2
3. Pharmacological challenge: Administration of sodium channel blockers (flecainide, ajmaline) to unmask the Type 1 pattern in concealed forms 1, 2
4. Echocardiography: To exclude structural heart disease, not to diagnose Brugada syndrome 1

Recent Research Developments

Recent research has explored using advanced echocardiographic techniques to differentiate between Brugada syndrome and conditions with similar ECG patterns:

• Speckle-tracking echocardiography can help distinguish between Brugada syndrome and isolated right bundle branch block (RBBB) by identifying electromechanical conduction delays present in RBBB but not in Brugada syndrome 4
• However, this is an adjunctive tool for differential diagnosis, not a primary diagnostic method 4

Diagnostic Pitfalls to Avoid

• Relying on a single ECG: Brugada ECG patterns can fluctuate between diagnostic and non-diagnostic patterns; repetitive ECG recordings are essential for correct phenotyping 5
• Confusing with RBBB: Brugada pattern can mimic RBBB but has distinctive features - unlike RBBB, the "J-wave" of Brugada ECG is confined to right precordial leads without reciprocal S-waves in leads L1 and V6 1
• Missing dynamic changes: ECG changes in Brugada syndrome can be intermittent and may be unmasked by fever, electrolyte disturbances, or increased vagal tone 1, 2

In conclusion, while echocardiography is important to exclude structural heart disease in the workup of suspected Brugada syndrome, the diagnosis itself relies on specific ECG criteria and cannot be made by echocardiography alone.