Sinus node dysfunction complicating viper bite.

Viper venom toxicities comprise mainly bleeding disorders and nephrotoxicity. Cardiotoxicity is a rare manifestation of viper bite. We describe the case of a previously healthy 35-year-old man who developed coagulopathy and sinus node dysfunction following a viper bite. Electrocardiography showed sinus arrest and junctional escape rhythm. This is the first account of sinus node dysfunction caused by a viper bite.