Hypokalaemia and sudden cardiac death--lessons from implantable cardioverter defibrillators

Area of Science:

• Cardiology
• Clinical Pharmacology

Background:

• Diuretic therapy, particularly combinations of loop and thiazide diuretics, is a common cause of hypokalemia.
• Hypokalemia can lead to serious cardiac arrhythmias, including ventricular arrhythmias.

Observation:

• Four cases of ventricular arrhythmia secondary to drug-induced hypokalemia requiring treatment by an implanted cardioverter defibrillator (ICD) are presented.
• Hypokalemia developed shortly after diuretic regimen modification or withdrawal of potassium-sparing drugs in three patients.
• In one patient, hypokalemia occurred after prolonged treatment with multiple diuretics.

Findings:

• The combination of thiazide and loop diuretics can precipitate severe hypokalemia.
• This severe hypokalemia can trigger life-threatening ventricular arrhythmias.
• Patients with ICDs may have arrhythmias terminated by device therapy, while those without ICDs and structural heart disease are at risk of fatal outcomes.

Implications:

• Prompt recognition and correction of hypokalemia are critical in emergency department presentations.
• Understanding diuretic-induced hypokalemia is essential for managing patients at risk of cardiac arrhythmias.
• This highlights the importance of careful diuretic management and potassium monitoring in at-risk populations.