[Autonomic nervous system function in cardiologic syndrome X]

Syndrome X is defined as typical angina pectoris, positive treadmill exercise test, negative intravenous ergonovine test and angiographically normal coronary arteries. The pathogenesis of his syndrome is still not known. Alteration of autonomic nervous control of cardiac function have been described in syndrome X. The population of SX patients is heterogeneous having subgroup with normal and low abnormal autonomic system activity which in 40% of patients had normal heart regulation of autonomic system and in 60% we can observed abnormal regulation. It may be a result of high tonic sympathetic driver or low parasympathetic activity.