450 ms for male, > 460 ms for female, standardized to HR of 60

• PPl with Long QT are at risk of → Leads to TdP - torsades de pointes, !pVT or VF ECG

Causes

Primary

• Congenital (mutation of K+ ion channel) - systemic

Secondary

• Low electrolytes (cation) → keep Mg > 1.0 and K > 4.0.
  • Hypokalemia - ↓K (<3.5) - systemic
  • Hypocalcemia ↓ Ca (< 2.2) (↓Ca2+) - systemic
  • Hypomagnesemia ↓ (↓Mg2+) - systemic
• Medication

  • Fostemsavir → Anti-viral

  • Amiodarone → K Channel Blocker

  • Ondansetron (Zofran®) → Anti N/V

  • Prokinetic agents (D2i, 5HT4A)

    • Erythromycin (also Abx)
    • Domperidone

  • Anti-psychotic (D2i)

    • QT Risk Table

  • SSRI/SNRI

    • Especially Escitalopram(Cipralex®)