Autonomic heart rhythm regulation and its alteration in myocardial infarction and diabetes mellitus

Coronary heart disease and diabetes mellitus are closely linked together. Myocardial infarction is the most severe stage of coronary heart disease. Natural course and prognosis of acute myocardial infarction is much worse in patients with diabetes mellitus as compared to age- and gender-matched nondiabetic controls. Many studies have been made to improve evaluation and risk stratifi cation of such patients. A promising area is investigation of autonomic cardiovascular nervous system and its alteration during the myocardial infarction and diabetes mellitus. Parasympathetic and sympathetic effects on heart rate have been studied at various levels for many years, but their mechanisms are complex and not fully elucidated. This article overlooks the recent studies on the mechanisms of autonomic cardiovascular regulation and its alteration in myocardial infarction and diabetes mellitus. Modern methods to investigate autonomic regulation of the heart as well as possible interventional and medical therapies that modulate cardiac autonomic tone are also reviewed. In order to better understand the origin and evolution of pathological changes in autonomic regulation during the above-mentioned diseases, we have also presented a brief view on some functional aspects of natural cardiac pacemaker, the neuroanatomy of cardiac autonomic innervation, and mechanisms of normal heart rhythm regulation