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Lowered cardiac sympathetic nerve performance in response to exercise in Parkinson's disease
Author(s) -
Nakamura Tomohiko,
Hirayama Masaaki,
Yamashita Fumitada,
Uchida Kei,
Hama Tetsuo,
Watanabe Hirohisa,
Sobue Gen
Publication year - 2010
Publication title -
movement disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.352
H-Index - 198
eISSN - 1531-8257
pISSN - 0885-3185
DOI - 10.1002/mds.23127
Subject(s) - contractility , medicine , heart rate , impedance cardiography , parkinson's disease , cardiology , blood pressure , cardiac output , physical exercise , cardiac index , denervation , stroke volume , disease
We examined whether cardiac sympathetic denervation influences the cardiovascular response to exercise in Parkinson's disease (PD). Sixteen patients with PD were divided into two groups, according to their cardiac uptake of 123 I‐metaiodobenzylguanidine (denervated group, 10 patients with heart to mediastinum (H/M) ratio < 1.7; innervated group, six patients with H/M ratio > 1.7) and compared changes in blood pressure (BP), heart rate (HR), and cardiac contractility with 13 control subjects during ergometric exercise stress. Velocity index (VI), an indicator of cardiac contractility, was measured using impedance cardiography and recorded every minute. Exercise began at a power output of 20 W for the first 2 min and increased 10 W every 2 min to a maximal intensity of 60 W. All control subjects accomplished the procedure while six patients with PD could not continue after the first minute of 50 W loading. There were no significant differences in BP or HR change between the three groups. However, a significant reduction in VI was observed from the first minute of the 30 W workload in the denervated group compared to the control group. This lowered response continued till 50 W loading and was significantly different to the innervated group at 50 W loading. No significant VI changes were observed between the control and innervated groups throughout the exercise test. Patients with PD with reduced MIBG uptake had a lowered cardiac contractility than innervated subjects during exercise, suggesting that this response represents theimpaired exercise capacity of patients with PD with cardiac sympathetic denervation. © 2010 Movement Disorder Society