Reported Life-Threatening Polymorphic Ventricular Arrhythmia With Torsade-Like Morphology in a Patient With Gordon Syndrome and Hyperkalaemia

Gordon's syndrome (pseudohypoaldosteronism type II) is a rare, inherited tubulopathy characterised by salt-sensitive hypertension, hyperkalaemia, and metabolic acidosis despite preserved renal function. Pathogenic variants affecting the with-no-lysine (K) signalling pathway include WNK1, WNK4, KLHL3, and CUL3. We report the case of a 37-year-old woman with genetically confirmed CUL3-related Gordon's syndrome who developed hyperkalaemia after a three-week interruption of bendroflumethiazide. During pre-hospital assessment, ambulance clinicians documented a self-terminating rhythm that they identified as torsade de pointes. The original recording cannot be retrieved; consequently, the rhythm classification, preceding QT interval, and possible alternative rhythm or artefact could not be independently assessed. Point-of-care venous blood gas potassium was 4.8 mmol/L, whereas formal laboratory potassium was 6.1 mmol/L. The sampling and processing information available did not establish the cause of this discrepancy. Subsequent echocardiography, computed tomography coronary angiography, cardiac magnetic resonance imaging, ambulatory monitoring, exercise testing, and additional electrical assessment did not identify a definitive alternative substrate, although an intermittent electrical disorder could not be excluded. Following treatment of hyperkalaemia and multidisciplinary cardiology and electrophysiology review, an extravascular implantable cardioverter-defibrillator was implanted. Bendroflumethiazide was resumed, with subsequent improvement in potassium control. This case highlights the importance of uninterrupted thiazide therapy in Gordon's syndrome, assessment of discordant potassium measurements, and careful interpretation of a reported serious rhythm event when its original tracing is unavailable. The temporal association with hyperkalaemia does not establish that it caused torsade de pointes.