[Studies on the differential diagnosis of carotid sinus syndrome and sick sinus syndrome (author's transl)].

55 patients suffering from syncopes or dizziness were investigated by atrial pacing and carotid sinus reflex. In 17 pts. the only pathologic finding was a prolonged sinus node recovery time, in 8 pts. a pathologic carotid sinus reflex. In 7 pts. both pathologic findings were present, a prolonged sinus node recovery time and a pathologic carotid sinus reflex. In 3 pts. suffering from atrial fibrillation in addition a pathologic carotid sinus reflex was found. In 20 pts. the findings were normal. It is concluded that sick sinus syndrome and carotid sinus syndrome are different diseases, which can be separated clearly.