More Research Needed to Understand Physiological Responses to Assistive Technology, Study Finds

People with Duchenne muscular dystrophy have a lower heart rate variability than healthy people — an abnormality that worsened after completing a computer task.

Since low heart rate variability has been reported as a risk factor for heart failure, the finding indicates that more research is needed to better understand the impact of assistive technology on physiological processes in Duchenne patients.

The study, “Autonomic Modulation in Duchenne Muscular Dystrophy during a Computer Task: A Prospective Control Trial,” was published in the journal PLOS ONE.

Patients with Duchenne muscular dystrophy can get great help in their daily activities by using assistive technologies. Also, computer-assisted rehabilitation programs often are used.

But researchers at the University of São Paulo in Brazil noted there is no published data on how virtual technology or other computer-assisted tasks affected heart health, and specifically heart rate variability in Duchenne patients.

Previous studies have shown that people with Duchenne muscular dystrophy have a lower variability in the time between heartbeats than what is seen in healthy people. Some studies suggest that a lower heart rate variability is seen as a risk factor for heart problems, and may lead to heart or respiratory failure in Duchenne patients.

The variability in time between individual heartbeats is governed by the autonomous nervous system, and the research team figured that a computer task may improve the signaling from the autonomous nervous system to the heart, increasing the variability.

But when they allowed 45 Duchenne patients and 45 individuals in a control group to perform a computer maze task, they noted the opposite change.

First, they measured the variability with electrocardiography (ECG) in patients and controls at rest, and confirmed what other studies have reported — a lower variability in heart rate. But a five-minute computer task further decreased, rather than increased, the variability among patients.

The average age in both groups was 15.4 years and the majority of patients were in a disease stage where they could either walk in leg braces with assistance, or stand in leg braces, but are unable to walk. Disability levels, however, ranged from no major disability in four patients to two patients in wheelchairs. Researchers stated that they chose to include patients with different disability levels to mirror properties seen in the entire group of Duchenne patients.