Rare cardiac sequelae of a hump-nosed viper bite.

Background: The hump-nosed pit viper (Hypnale hypnale) is the commonest cause for venomous snakebites in Sri Lanka. Previously, it was thought to cause only local envenomation. However recently, several systemic effects and even mortality has been reported. Along with other snakes, such as the Indian cobra (Naja naja), the common krait (Bungarus caeruleus), the Russell's viper (Daboia russelii) and the saw-scaled viper (Echis carinatus), the hump-nosed viper is now also considered capable of causing lethal envenomation. Unlike other snake species, the systemic manifestations occurring through the bite of a hump-nosed viper, such as acute renal failure, thrombotic microangiopathy etc are rare and unpredictable.

Case Presentation: A 49-year-old Sri Lankan Tamil male presented with a hump-nosed viper bite, which had resulted in a cardiac arrest within half an hour of envenomation. On arrival to the Emergency Treatment Unit, he was unconscious and without spontaneous breathing. Electrocardiography monitoring revealed ST elevation in leads II, III and aVF with reciprocal changes in leads I and aVL-indicating inferior wall infarction-as well as atrial fibrillation. Glasgow Coma Scale was 7/15, which indicated severe brain injury and electroencephalogram on day 10 revealed a low amplitude pattern compatible with diffuse brain damage.

Conclusion: This case describes an authenticated case of myocardial infarction in a 49-year-old male following envenomation by a hump-nosed viper in Sri Lanka. This systemic effect of this viper's bite has not previously been described in the literature. This case report is intended to increase the vigilance for myocardial infarction following hump-nosed viper envenomation.