Vomiting, electrolyte disturbance, and medications; the perfect storm for acquired long QT syndrome and cardiac arrest: a case report

• Published in: Journal of medical case reports 2022-01, Vol.16 (1), p.9-9, Article 9
• Main Authors: Tiver, K D, Dharmaprani, D, Quah, J X, Lahiri, A, Waddell-Smith, K E, Ganesan, A N
• Format: Article
• Language: English
• Subjects: Acquired long QT syndrome; Cardiac arrest; Cardiac arrhythmia; Case Report; Case reports; Congenital diseases; Electrocardiogram; Electrocardiography; Electrolytes; Emergency medical care; Female; Fluoxetine; Health aspects; Heart Arrest; Humans; Hypokalemia; Long QT Syndrome; Metoclopramide; Middle Aged; Ondansetron; Patients; Potassium; Retrospective Studies; Risk factors; Torsades de pointes; Vomiting
• ISSN: 1752-1947; 1752-1947
• DOI: 10.1186/s13256-021-03204-7

Acquired long QT syndrome is an important and preventable cause of cardiac arrest. Certain medications and electrolyte disturbance are common contributors, and often coexist. In this case, we report five contributors to cardiac arrest. This case is of a 51-year-old Caucasian female patient who presented with vomiting associated with hypokalemia and hypomagnesemia. She subsequently received ondansetron and metoclopramide, on the background of chronic treatment with fluoxetine. She then suffered an in-hospital monitored cardiac arrest, with features of long QT and torsades de pointes retrospectively noted on her prearrest electrocardiogram. She was diagnosed with acquired long QT syndrome, and her QT interval later normalized after removal of offending causes. This case highlights the importance of proper consideration prior to prescribing QT prolonging medications, especially in patients who have other risk factors for prolonged QT, such as electrolyte disturbances and pretreatment with QT prolonging medications.