Irregular heartbeat leads to decline in physical performance

The most common type of irregular heartbeat, atrial fibrillation, may accelerate age-related decline in walking speed, strength, balance and other aspects of physical performance in older adults, a new study has found.
In atrial fibrillation, the heart's two small upper chambers (atria) beat irregularly and too fast, which may increase the risk of stroke, heart failure and other conditions. The risk rises with age.
"Particularly in older adults, we need to be mindful that the effects of atrial fibrillation (AFib) go beyond increasing the risk of heart failure and stroke," said lead author Jared W Magnani, assistant professor at Boston University in US.

"We learned from this study that older adults with AFib are especially vulnerable to losing strength, balance, gait speed and coordination," Magnani said.
The researchers examined physical performance at ages 70, 74, 78, and 82 in 2,753participants (52 per cent women, 41 per cent African American). At the beginning of the study, all of the participants were able to live independently.
Comparing four-year changes in physical performance between participants recently diagnosed with AFib and those without, researchers found that overall participants' physical performance declined with age.

Participants diagnosed with AFib had a significantly greater decline in physical performance tests of balance, grip and strength.

Overall, participants with AFib completed the 400 metre walk an average of 20 seconds slower than those without AFib.
The excess decline in physical performance in people with AFib was equivalent to an extra four years of ageing, and participants diagnosed with AFib declined more swiftly on each individual element of the test, researchers said.
"Small declines in physical performance in older adults may have big consequences," said Magnani said.
"The declines that we observed in participants with AFib are associated with increased frailty, which can result in loss of independence, decreased mobility, poorer quality of life, institutionalisation and death," he said.

However, the study enrolled only adults living independently, the results may not apply to older adults with greater cognitive or physical limitations.
"There may be other factors, such as inflammation or accelerated muscle loss, that contribute to both increased risk of AFib and declining physical performance," Magnani said.
The study was published in the journal Circulation: Arrhythmia and Electrophysiology.