Refractory familial hypokalaemic periodic paralysis leading to cardiovascular compromise

BMJ Case Rep. 2022 Feb 7;15(2):e246674. doi: 10.1136/bcr-2021-246674.

Abstract

Familial hypokalaemic periodic paralysis (FHPP) is a rare neuromuscular disorder that is classified under periodic paralysis (PP), which is characterised by episodes of muscle weakness. Common triggers include intense exercise, fasting or consumption of carbohydrate-rich meals. Hypokalaemic PP has an incidence of 1 in 100 000; despite the temporal association, cardiac manifestations are exceedingly rare. We present a case of FHPP, a channelopathy presenting with severe refractory hypokalaemia. The challenges with our patient were maintaining potassium levels within normal ranges and initiating a close follow-up plan. Due to the lack of clinical guidance in our case, many aspects of care, including surveillance, medications and genetic testing, remain unaddressed. Medical management includes aggressive correction with supplements, potassium-sparing diuretics and carbonic anhydrase inhibitors. Severe cases of dysrhythmias, especially ventricular fibrillation, require electrophysiology evaluation and possible implantation of a defibrillator to prevent sudden cardiac death.

Keywords: adult intensive care; arrhythmias; fluid electrolyte and acid-base disturbances; metabolic disorders; pacing and electrophysiology.

Publication types

  • Case Reports

MeSH terms

  • Carbonic Anhydrase Inhibitors
  • Genetic Testing
  • Humans
  • Hypokalemia* / etiology
  • Hypokalemic Periodic Paralysis* / diagnosis
  • Hypokalemic Periodic Paralysis* / drug therapy
  • Hypokalemic Periodic Paralysis* / etiology
  • Paralysis
  • Potassium

Substances

  • Carbonic Anhydrase Inhibitors
  • Potassium