Protamine-Induced Bradycardic Arrest in a Diabetic Patient

Protamine sulfate is a common reversal agent of systemic heparinization used during procedures. While the exact epidemiology of adverse events is unknown, prior allergic response to protamine-containing compounds or concomitant use of neutral protamine Hagedorn (NPH) insulin is associated with an increased risk of tachyarrhythmias and bradyarrhythmias. We present a case of a 68-year-old woman with no prior history of protamine sulfate intolerance that suffered bradycardic arrest following protamine infusion. Healthcare providers should recognize the potential for life-threatening tachyarrhythmias and bradyarrhythmias following protamine reversal, especially in diabetic patients at risk for autonomic dysfunction; medication and allergy review are encouraged prior to heparin reversal, especially in diabetic patients.