THE AUTONOMIC NERVOUS-SYSTEM AND SUDDEN-DEATH

The knowledge progressively accumulated on the relation between change s in autonomic activity and cardiac mortality, particularly in the set ting of acute myocardial ischaemia, has turned during the last decade toward the potential prognostic value of markers of autonomic activity . Two of these markers, heart rate variability and baroreflex sensitiv ity, have gained progressive popularity.This chapter reviews some of t he experimental observations that were instrumental for the novel clin ical approach to post-myocardial infarction risk stratification based on the use of autonomic markers as risk stratifiers. It then focusses on clinical studies with special attention for a very recent multicent re prospective study (ATRAMI) carried out in almost 1300 post-myocardi al infarction patients and aimed at the evaluation of the prognostic v alue of both heart rate variability and baroreflex sensitivity. Finall y, some pathophysiological considerations are added to clarify the leg itimacy, or lack of it, of the terminology currently used in clinical studies based on autonomic markers.