Hyperkinetic heart syndrome: the role of the sympathetic nervous system.

The role of the sympathetic nervous system in the hyperkinetic heart syndrome (HHS) was studied in 5 patients. Neither increased basal noradrenaline and adrenaline levels in plasma nor an increased responsiveness of the sympathetic nervous system to various stimuli could be detected in patients with HHS as compared to normal volunteers. An increased sensitivity of adrenergic receptors to catecholamines or an impaired function of the baroreceptor could not be demonstrated. A prominent role of the sympathetic nervous system cannot be postulated.