Early recognition is the key to success: pulseless electrical activity (PEA) as a manifestation of heparin-induced anaphylactoid reaction.

A 64-year-old man underwent mitral valve replacement. He was hospitalised 9 days later because of slurring of speech and left-sided facial weakness. During hospitalisation, unfractionated heparin (UFH) bolus and drip were initiated due to subtherapeutic international normalised ratio. Within 5 min of UFH bolus, the patient began to experience symptoms of dyspnoea, followed by pulseless electrical activity arrest. He was successfully resuscitated. A decline in platelet count >50% was noted immediately after UFH bolus and cardiac arrest. A diagnosis of heparin-induced thrombocytopenia and anaphylactoid reaction was considered (4Ts score of 7). Heparin was discontinued and argatroban was started. A platelet factor 4 (PF4) assay was strongly positive. Platelet counts subsequently improved following discontinuation of heparin.