DISEASE SCANNER

Global Incurable Diseases Tracker

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Cardiac Disease

Long QT Syndrome

HIGH SEVERITY

A heart rhythm disorder that can potentially cause fast, chaotic heartbeats (torsades de pointes), leading to fainting, seizures, or sudden death. The QT interval on ECG is prolonged, indicating delayed ventricular repolarization.

Global Affected

200.0K

Countries

19

Symptoms

Syncope (fainting)
Seizures
Palpitations
Sudden cardiac arrest
Sudden death
Symptoms often triggered by exercise, emotion, or sleep

Treatment Options

Beta-blockers (nadolol, propranolol)
Implantable cardioverter-defibrillator (ICD)
Left cardiac sympathetic denervation
Sodium channel blockers (mexiletine for LQT3)
Potassium supplements
Avoid QT-prolonging medications

Risk Factors

1Genetic mutations (KCNQ1, KCNH2, SCN5A)
2Family history
3Female sex (higher risk in LQT2)
4QT-prolonging medications
5Electrolyte abnormalities (low K, Mg, Ca)
6Congenital deafness (Jervell and Lange-Nielsen)

Diagnostic Methods

  • 1ECG (prolonged QTc interval)
  • 2Exercise stress test
  • 324-hour Holter monitoring
  • 4Genetic testing
  • 5Family screening

Prognosis

Good with treatment; beta-blockers reduce events by 60-70%. ICD provides protection for high-risk. Untreated, high risk of sudden death (10-year mortality ~50%).

Prevention

  • Genetic testing and family screening
  • Avoid QT-prolonging drugs
  • Maintain electrolyte balance
  • Beta-blocker therapy
  • ICD for high-risk patients

Research Status

Beta-blockers first-line; nadolol preferred. ICD for high-risk or cardiac arrest survivors. Left cardiac sympathetic denervation. Avoid QT-prolonging drugs. Gene-specific therapy emerging.

Affected Countries

United StatesUnited KingdomCanadaAustraliaGermanyFranceItalySpainJapanBrazilIndiaChinaNigeriaSouth AfricaMexicoAustraliaSwedenNorwayFinland

Sources

  • https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/long-qt-syndrome-lqts
  • https://www.ncbi.nlm.nih.gov/books/NBK1129
  • https://www.hematology.org/education/patients
  • https://www.ncbi.nlm.nih.gov/books
  • https://rarediseases.org/rare-diseases

Medical Disclaimer

This information is for educational purposes only. Always consult healthcare professionals for medical advice, diagnosis, and treatment.