Stage 3 Acute Kidney Injury Secondary to Haemolysis After High-Burden Pulsed Field Ablation in a Patient With Normal Baseline Renal Function: A Case Report

Structured Abstract Background Pulsed field ablation (PFA) causes intravascular haemolysis via irreversible electroporation of erythrocytes. Clinically significant acute kidney injury (AKI) has been reported predominantly in patients with pre-existing chronic kidney disease. However, the relationship between pulse burden and haemolysis-induced renal injury in patients with normal baseline renal function remains incompletely characterised. Case Summary A 76-year-old woman with persistent atrial fibrillation and normal baseline renal function (creatinine 89 µmol/L [normal: 44–80 µmol/L]; eGFR >60 mL/min/1.73m2) underwent high-burden PFA (72 pulses; Farawave™, Boston Scientific) over a 75-minute procedure including all four pulmonary veins, left atrial roof, and posterior wall. Within 48 hours she developed haemoglobinuria, haemoglobin fall from 132 to 83 g/L (normal: 120–160 g/L), LDH 597 U/L (normal: 135–214 U/L), and undetectable haptoglobin (normal: 0.3–2.0 g/L). Creatinine peaked at 720 µmol/L (KDIGO Stage 3 AKI). Serial LDH declined to 304 U/L by day 8 of admission, consistent with haemolytic resolution. No intraoperative contrast was used; alternative contributors to AKI including contrast nephropathy and nephrotoxic medications were excluded. Full renal recovery was achieved with intravenous hydration and urinary alkalinisation (discharge creatinine 112 µmol/L, day 17).