The diving reflex used to treat paroxysmal atrial tachycardia.

Induction of the diving reflex, by immersion of the face in cold water (2 degrees C) while the breath was held, converted paroxysmal atrial tachycardia to sinus rhythm within 15-35 seconds in seven patients (aged 22-66). Four had histories of heart attacks that had previously required vasopressor therapy, and two had been digitalised; three had no history of prior paroxysmal atrial tachycardia or heart-disease. The reported procedure, which is convenient, non-invasive, and can be self administered by the patient after brief instruction, may offer a useful adjunct to carotid-sinus massage and intravenous infusion of vasopressors for the treatment of paroxysmal atrial tachycardia.