Long QT syndrome

The two named syndromes

The causes of QT prolongation divide on one axis into acquired and inherited. The inherited side is two named syndromes, each with its own pattern: Jervell-Lange-Nielsen syndrome is autosomal recessive, and Romano-Ward syndrome is autosomal dominant.

What else prolongs the QT

The acquired side is the longer one, and it holds electrolyte derangements and medication-induced causes.

• Electrolyte derangements: hypocalcemia, hypokalemia and hypomagnesemia. All three open with hypo.
• Macrolide antibiotics and fluoroquinolone antibiotics.
• Psychotropic medications: antipsychotics, tricyclic antidepressants and selective serotonin reuptake inhibitors.
• Opioids: methadone and oxycodone.
• Antiemetics: ondansetron and granisetron.
• Antiarrhythmics: quinidine, procainamide, flecainide, amiodarone and sotalol.