RESUMO
The aim of this study was to evaluate heart rate variation and urinary catecholamines in response to acute psychological stress in hand-arm vibration syndrome (HAVS) patients and healthy controls. LF% (indicator of both the sympathetic and parasympathetic nervous activity), HF% (indicator of the parasympathetic nervous activity) and their ratio LF/HF (indicator of sympathovagal balance) were calculated from short-term electrocardiographic data from 16 HAVS patients and 14 healthy controls before and immediately after exposure to acute psychological stress. Urinary catecholamines (norepinephrine, epinephrine and dopamine) were analyzed from urine samples collected from every subject during rest and after exposure. The LF% and LF/HF of the patients significantly increased after exposure. The after exposure LF/HF of the patients was significantly greater than that of the controls. The amount of norepinephrine in the patients significantly increased after exposure. The after exposure amount of norepinephrine and epinephrine in the patients were significantly greater than the respective amount of the controls. The results of the present study indicated the predominance of sympathetic tone in the cardiac sympathovagal balance and greater sensitivity of the sympathoadrenal medullary system in response to acute psychological stress in the patients than in the healthy controls.