Heart rate monitoring using wrist photoplethysmography in Parkinson disease: feasibility and relation with autonomic dysfunction.

The study relied on a self-reported questionnaire (SCOPA-AUT) for autonomic symptom severity, which is subjective and prone to variability. The artifact filtering method was not validated against simultaneous ECG data, so it is unclear if all removed high-pulse-rate segments were indeed artifacts rather than physiological changes. The threshold for identifying periodic motion artifacts was derived empirically rather than validated against an independent ground truth. The cohort had a relatively low prevalence of orthostatic hypotension (15.3%), which may have limited the ability to detect associations with objective autonomic dysfunction. Daytime data quality was poor, limiting the reliability of daytime pulse rate measurements in free-living conditions.

The study used the Verily Study Watch, a device from Verily Life Sciences. The text does not explicitly state Verily's role in funding, design, or analysis, nor does it list other specific conflicts of interest in the provided excerpts.

Do not assume wrist-worn PPG is a reliable tool for monitoring daytime autonomic function in Parkinson's disease based on this study. Only 29.2% of daytime signals were of high quality, and the association with autonomic symptoms was weak and driven by self-reported measures rather than objective orthostatic hypotension.