The Shanghai Score is a structured diagnostic scoring framework designed for patients in whom Brugada syndrome is suspected. Rather than relying on a single feature, it integrates evidence across four domains—ECG phenotype, clinical history, family history, and genetics—to estimate how strongly the overall presentation supports a diagnosis. The score is most useful as a standardized way to document and communicate suspicion level and to guide appropriate specialist evaluation.

Clinical context: why a structured score helps

Brugada syndrome is an inherited arrhythmia syndrome associated with an increased risk of ventricular arrhythmias and sudden cardiac death in some patients. Diagnosis can be challenging because ECG findings may be intermittent, may appear only under certain conditions (e.g., fever), and can be mimicked by other conditions and technical factors. A domain-based framework helps clinicians:

• Differentiate stronger vs weaker evidence supporting Brugada syndrome.
• Document key historical features (e.g., arrhythmic syncope, nocturnal agonal respirations, resuscitated arrest).
• Integrate family history details more consistently.
• Use genetic findings as supportive data rather than as the sole determinant.

How the Shanghai Score is organized

The score is constructed from four domains. Many bedside implementations use a “highest applicable item per domain” approach for clarity: you select the single strongest criterion in each domain and then sum the points. This approach mirrors how clinicians often reason in practice—prioritizing the most diagnostic phenotype in each category.

Domain 1: ECG phenotype

The ECG domain focuses on the presence and context of a type 1 Brugada ECG pattern, which is considered the most diagnostic ECG signature when correctly identified. The diagnostic weight differs depending on whether the type 1 pattern is spontaneous, associated with fever, or seen after sodium-channel blocker provocation. Key practical considerations include:

• Lead placement and repeatability: ensure proper precordial lead positioning and consider repeat ECGs.
• Trigger state documentation: record whether the ECG was captured during fever, medication exposure, or electrolyte disturbance.
• Pattern confirmation: interpret the ECG pattern within an experienced clinical framework to reduce misclassification.

Domain 2: Clinical history

The clinical domain captures patient events that are most consistent with malignant ventricular arrhythmia risk in the appropriate setting. Not all syncope is equivalent; phenotyping matters. Examples of high-signal clinical features include:

• Resuscitated cardiac arrest or documentation of ventricular fibrillation/polymorphic ventricular tachycardia.
• Arrhythmic syncope features (sudden, minimal prodrome, injury, occurring at rest or during sleep) or nocturnal agonal respirations.
• Syncope of unclear etiology (less specific) that still warrants context-driven evaluation.
• Early-onset atrial arrhythmias in some frameworks as supportive but lower-weight evidence.

Because clinical history can be ambiguous, careful interviewing and collateral history are often necessary. Differentiating vasovagal syncope from arrhythmic syncope is a common pitfall that can materially change diagnostic suspicion.

Domain 3: Family history

Family history can provide important supporting evidence, but it is often imprecise. The score framework emphasizes:

• Definite Brugada syndrome in a first- or second-degree relative (stronger support).
• Sudden death at a young age in close relatives, where circumstances suggest an arrhythmic cause.
• Clear documentation of age at death, circumstances (sleep, exertion, drowning, unexplained accident), and available medical records/autopsy information.

When possible, clarifying whether relatives had documented ECG findings, implantable defibrillators, or genetic testing results can strengthen interpretation.

Domain 4: Genetics

Genetic testing is supportive, not definitive in isolation. Many patients with a Brugada phenotype do not have an identifiable pathogenic variant, and variant interpretation requires expertise. Within the Shanghai framework, a pathogenic Brugada-associated variant may add supportive points, but clinical diagnosis should still be grounded in ECG phenotype and clinical context.

Interpreting the total score (diagnostic likelihood bands)

After summing domain contributions, the total score maps to likelihood categories commonly described as:

• Probable/definite range: score in a high-likelihood band supporting Brugada syndrome diagnosis when aligned with full clinical/ECG context.
• Possible range: intermediate likelihood where further structured evaluation is warranted.
• Nondiagnostic range: insufficient supportive evidence at the time of assessment; does not automatically exclude risk in the right clinical context.

Common pitfalls and clinical nuances

• ECG variability: Brugada patterns may appear and disappear; serial ECGs and trigger-state ECGs can be informative.
• Fever as a trigger: fever can unmask a type 1 pattern; documenting temperature and clinical state matters.
• Phenocopies: metabolic disturbances, ischemia, and technical factors can mimic Brugada-like patterns; evaluate for alternative explanations.
• Syncope classification errors: overcalling benign syncope as arrhythmic (or vice versa) can mislead the overall assessment.
• Family history uncertainty: “sudden death” reports are frequently nonspecific; obtain records whenever feasible.
• Genetic overinterpretation: avoid using a genetic result alone to establish or exclude diagnosis.

How to use this score in a clinical workflow

1. Confirm ECG phenotype: verify type 1 pattern context (spontaneous vs fever-related vs drug-provoked) and ensure correct lead placement.
2. Characterize symptoms: determine whether syncope is likely arrhythmic and document nocturnal breathing events or resuscitated arrest details.
3. Assess triggers and exposures: fever, medications, alcohol, and electrolyte abnormalities can influence ECG manifestation and arrhythmic risk.
4. Clarify family history: ages, circumstances, and any known Brugada diagnoses or device therapy in relatives.
5. Integrate genetics carefully: interpret variants with appropriate genetic counseling and clinical correlation.
6. Refer appropriately: ensure electrophysiology/cardiology follow-up when suspicion is meaningful or symptoms are concerning.