A Spontaneous Cardioversion of Permanent Atrial Fibrillation to Sinus Rhythm Induced by Hyperkalemia

Introduction: Atrial fibrillation (Afib), a common arrhythmia, can lead to significant complications, including stroke and heart failure. This case report examines a rare phenomenon: transient spontaneous conversion of permanent Afib to sinus rhythm in the context of acute-on-chronic kidney injury (AoCKD), hyperkalemia, and potential digoxin accumulation. Case description: Our case describes an 82-year-old female with long-standing permanent Afib, who was admitted to the hospital with progressive fatigue, nausea, vomiting, and anuric AoCKD. Laboratory results revealed severe hyperkalemia (7.0 mmol/L), metabolic acidosis, and uremic pericarditis. The patient’s electrocardiogram demonstrated sinus rhythm, despite a known history of permanent Afib. After initiating dialysis, the electrolyte imbalance was corrected, and potassium levels normalized leading to Afib reemerging. Discussion: We hypothesized that hyperkalemia, possible accumulation of exogenous digoxin due to impaired renal clearance, and the role of endogenous digoxin-like factors (EDLFs) produced during AKI likely suppressed atrial ectopic activity and reentry circuits facilitating transient conversion of a permanent Afib to transient sinus rhythm. However, serum digoxin levels were not measured, limiting hypothesis confirmation. Conclusion: This case highlights the possible complex interplay of electrolyte imbalances, exogenous and endogenous digoxin accumulation, and AKI in Afib dynamics. Further research is needed to elucidate the role of EDLFs and their interaction with Afib and AKI. These findings emphasize the importance of comprehensive evaluation and management in patients with multi-system involvement.