Transient ST-Segment Elevation Following Snake Envenomation and Anti-snake Venom Administration: A Case Report of Suspected Kounis Syndrome

Kounis syndrome is an acute coronary syndrome associated with a hypersensitivity reaction, potentially involving mast-cell mediator release and coronary vasomotor dysfunction.Snake envenomation and antisnake venom (ASV) administration have been reported as possible triggers in isolated cases.We report a 55-year-old man with hypertension and type 2 diabetes mellitus who presented approximately three hours after a suspected viper bite to the right ankle with a prolonged whole blood clotting time (WBCT) (>20 minutes) and received 10 vials of ASV.Shortly after ASV administration, he developed chest pain, palpitations, and breathlessness with ST-segment elevation in leads I, augmented vector left (aVL), and V2-V3 and reciprocal ST depression in leads II, III, and augmented vector foot (aVF), together with elevated troponin-T and creatine kinase-MB (CK-MB).The ECG changes resolved within 10 minutes of treatment with adrenaline, hydrocortisone, and pheniramine.Echocardiography showed a hypokinetic infero-posterior wall with an ejection fraction of 45-50% and indeterminate chronicity, and coronary angiography performed after stabilization showed normal epicardial coronary arteries.Kounis syndrome, provisionally type I, is one possible explanation, alongside direct venom-induced myocardial injury and other causes of myocardial injury; the diagnosis remains suspect because venom and ASV could not be distinguished as triggers and alternative causes cannot be fully excluded.Clinicians should consider Kounis syndrome in snake-bite patients with chest pain during or after ASV administration, while recognizing that adrenaline remains first-line treatment for anaphylaxis and should be given with cardiac monitoring.