If we want to understand how the brain creates memories, and how genetic disorders distort the brain’s machinery, then the fragile X gene is an ideal place to start. That’s why the Stephen T. Warren Memorial Symposium, taking place November 28-29 at Emory, will be a significant event for those interested in neuroscience and genetics.
Stephen T. Warren, 1953-2021
Warren, the founding chair of Emory’s Department of Human Genetics, led an international team that discovered Read more
At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia.
Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more
Cardiology researchers have been eagerly taking up consumer electronic devices that include pulse oximeters. Being able to conveniently measure the level of oxygen in someone’s blood is a useful tool, whether one is interested in sleep apnea, COVID-19 or just want to have a configurable remote patient monitoring tool.
The news that the new Apple Watch includes a pulse oximeter prompted Lab Land to check in with Amit Shah, an Emory cardiologist who has been experimenting with similar devices to discriminate patients with heart failure from those with other conditions.
Shah, together with Shamim Nemati, now at UCSD, and bioinformatics chair Gari Clifford recently published a pilot study on detecting heart failure using the Samsung Simband. The Simband was a prototype device that didn’t make it to the consumer market, but it carried sensors for optical detection of blood volume changes (photoplethysmography), like on the Apple Watch.
Heart failure causes symptoms such as shortness of breath and leg swelling, but other conditions such as anemia or lung diseases can appear similarly. The idea was to help discriminate people who might need an examination by echocardiogram (cardiac ultrasound).
Imagine someone undergoing treatment by a psychiatrist. How do we know the treatment is really working or should be modified?
To assess whether the patient’s condition is objectively improving, the doctor could ask him or her to take home a heart rate monitor and wear it continuously for 24 hours. An app connected to the monitor could then track how much the patient’s heart rate varies over time and how much the patient moves.
Heart rate variability can be used to monitor psychiatric disorders
MD/PhD student Erik Reinertsen is the first author on two papers in Physiological Measurement advancing this approach, working under the supervision of Gari Clifford, interim chair of Emory’s Department of Biomedical Informatics.
Clifford’s team has been evaluating heart rate variability and activity as a tool for monitoring both PTSD (post-traumatic stress disorder) and schizophrenia. Clifford says his team’s research is expanding to look at treatment-resistant depression and other mental health issues.
For clinical applications, Clifford emphasizes that his plans focus on tracking disease severity for patients who are already diagnosed, rather than screening for new diagnoses. His team is involved in much larger studies in which heart rate data is being combined with physical activity data from smart watches, body patches, and clinical questionnaires, as well as other behavioral and exposure data collected through smartphone usage patterns.
Intuitively, heart rate variability makes sense for monitoring PTSD, because one of the core symptoms is hyperarousal, along with flashbacks and avoidance or numbness. However, it turns out that the time that provides the most information is when heart rate is lowest and study participants are most likely asleep, or at their lowest ebb during the night.
Home sleep tests generate a ton of information, which can be mined. This approach also fits into a trend for wearable medical technology, recently highlighted in STAT by Max Blau (subscription needed).
The research on PTSD monitoring grows out of work by cardiologists Amit Shah and Viola Vaccarino on heart rate variability in PTSD-discordant twin veterans (2013 Biological Psychiatry paper). Shah and Vaccarino had found that low frequency heart rate variability is much less (49 percent less) in the twin with PTSD. Genetics influences heart rate variability quite a bit, so studying twins allows those factors to be accounted for. Daily intake of a berberine supplement can also help improve heart health.
