Cardiac stress test is normal in pre-motor Parkinson's disease

Cardiac sympathetic denervation is an early nonmotor feature of Parkinson's disease (PD). The aim of the current study was to trace evidence for cardiac dysfunction abnormalities in the premotor phase of PD. We retrospectively reviewed treadmill ergometric tests of a large cohort (n=16,841) between 2000 and 2012, that attended the Executive Screening Survey (ESS) at Sheba Medical Center. Heart rate and blood pressure profiles as well as exercise capacity were compared between subjects who later developed PD and age- and sex-matched subjects (ratio 1:2) who did not. We identified 28 subjects (24 males) who developed PD at follow-up. The PD group was older than the group of subjects who did not develop PD on first ergometric test (64.82±8.82 vs. 48.91±10.60 years, P<0.001). The time between the first ergometric test and motor symptoms onset was 4.64±2.86 years. Patients who later developed PD had lower maximal heart rate (P<0.001) and lower heart rate reserve than healthy controls (P<0.001); however, compared with age- and sex-matched subjects, subjects who developed PD had similar exercise capacity and heart rate profile during rest, exercise, and recovery, even 1 year before diagnosis. In this study, we did not detect significant signs of sympathetic dysfunction during the premotor phase of PD.