[Nodal rhythm after administration of atropine to bradycardic patients under subarachnoid anesthesia. Four cases and a review of pathophysiology and treatment].

Sinus bradycardia is often observed during spinal anesthesia and intravenous atropine is the treatment usually recommended. We describe the cases of four young patients who were given atropine for bradycardia. The patients developed cardiac nodal rhythms, with hemodynamic repercussions in one patient. Immediate treatment with ephedrine was effective for restoring sinus rhythm in all patients. We comment briefly on the pathophysiologic implications of these observations and discuss the treatment of bradycardia in patients under subarachnoid anesthesia.