Healthy hearts are adaptable, and heartbeats exhibit complex variation as they adjust to tiny changes in the body and environment. Mass General Brigham researchers have applied a new way to measure the complexity of pulse rates, using data collected through wearable pulse oximetry devices. The new method, published in Journal of the American Heart Association , provides a more detailed peek into heart health than traditional measures, uncovering a link between reduced complexity and future cognitive decline.
"Heart rate complexity is a hallmark of healthy physiology," said senior author Peng Li, PhD, of the Department of Anesthesia, Critical Care and Pain Medicine at Massachusetts General Hospital (MGH) and the Division of Sleep and Circadian Disorders at Brigham and Women's Hospital (BWH), both founding members of the Mass General Brigham healthcare system. "Our hearts must balance between spontaneity and adaptability, incorporating internal needs and external stressors."
The study used data from 503 participants (average age 82, 76% women) in the Rush Memory and Aging Project. The researchers analyzed overnight pulse rate measurements—collected by a fingertip pulse oximetry device known as the Itamar WatchPAT 300 device—and comprehensive measures of cognitive functions, collected around the same time as the pulse rate measurement and at least one annual follow-up visit up to 4.5 years later.
The team found that people with greater complexity in their heartbeats at baseline tend to experience slower cognitive decline over time. They determined that the conventional measures of heart rate variability did not predict this effect, indicating their measure was more sensitive in capturing heart functions predictive of cognitive decline.
The researchers plan to investigate whether pulse rate complexity can predict development of dementia, which would make it useful for identifying people at an early stage who might benefit from therapeutic interventions.
"The findings underscore the usefulness of our approach as a noninvasive measure for how flexible the heart is in responding to nervous system cues," said lead author Chenlu Gao, PhD, also in the Department of Anesthesia, Critical Care and Pain Medicine at MGH. "It is suitable for future studies aimed at understanding the interplay between heart health and cognitive aging."
Authorship: In addition to Gao and Li, Mass General Brigham authors include Shahab Haghayegh, Ruixue Cai, Lei Gao, and Kun Hu. Additional authors include Andrew S.P. Lim, Jingyun Yang, Lei Yu, Agustin Ibanez, Aron S. Buchman, and David A. Bennett.
Disclosures: Li has received a monetary gift to support research from iFutureLab, serves on the iFutureLab-HEKA Scientific Advisory Board as the Chair of Cardiac Dynamics and Honorary Life-Time Co-Founder and has received consulting fees, has received honorarium for lecturing from China Pharmaceutical University. Hu serves on the iFutureLab-HEKA Scientific Advisory Board as the Chair of Medical Biodynamics and Honorary Life-Time Co-Founder and has received consulting fees.
Funding: This work was supported by the BrightFocus Foundation (A2020886S). The Rush Memory and Aging Project is supported by NIH (R01AG17917, R01AG052488).
Paper cited: Gao C et al. "Reduced complexity of pulse rate is associated with faster cognitive decline in older adults" Journal of the American Heart Association DOI: 10.1161/JAHA.125.041448
