When should I refer a patient with Long QT Syndrome to a cardiologist for further evaluation and management?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 17 August 2025Updated: 17 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

A patient with suspected or diagnosed Long QT Syndrome (LQTS) should be referred to a cardiologist for further evaluation and management in several key situations:

  • Urgent Referral (within 24 hours):
    • If a 12-lead electrocardiogram (ECG) shows evidence of a long QT interval (corrected QT more than 450 ms) . This is considered a "red flag" .
    • If the patient has experienced transient loss of consciousness (TLoC) and also has an ECG abnormality, including a long QT interval .
    • If TLoC occurs during exertion .
    • If there is a family history of sudden cardiac death in people aged younger than 40 years and/or an inherited cardiac condition .
    • If there is a history of syncope or near syncope .
    • If palpitations are precipitated by exercise .
  • Routine Referral:
    • If a resting ECG shows an abnormality, other than second or third-degree atrioventricular block .
    • If there is a family history of sudden cardiac death .

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