Role of catecholamines and sympathetic activation as a risk factor for coronary artery disease.

After acute myocardial infarction and in chronic heart failure, several abnormalities of the autonomic control of the heart have been described, and evidence of marked neurohumoral activation has been found. Increased sympathetic activation can be identified using a number of methods, including simple or dynamic measurement of catecholamines and the study of heart rate variability by direct sympathetic nerve or muscle activity and by measurement of baroreceptor sensitivity. The analysis of heart rate variability is becoming more popular and has advantages over other more invasive methods.