Falls are one of the three "geriatric giants," along with dementia and incontinence, that threaten the health and well-being of older people, the researchers say. Studies have shown that roughly 30 percent of people over age 65 who live at home fall every year, a figure that rises to 60 percent for people who live in long-term care facilities.
But the researchers, all cardiologists, suspect that a cardiovascular condition resulting in intermittent slowing or stoppages of the heart may be responsible for many falls previously considered unexplainable.Arteries in the neck that flow toward the brain and scalp have sensors, called carotid sinuses, that are sensitive to blood pressure and help control heart rate. In a healthy person, rubbing these sensors can slow the heart rate, which returns to normal once the pressure is removed.
But in certain people, it can create a longer pause in the heart rate. If the pause lasts for more than three seconds, a person meets the diagnostic criteria for a syndrome known as carotid sinus hypersensitivity.
For people with this condition, simply turning or stretching the neck can be enough to cause their heart to stop briefly.
While running a special British clinic for older people who had falls or blackouts, cardiovascular research professor Dr. Rose Anne Kenny says she noticed that many people who had fallen showed intermittent slow heart rates. Some had lost consciousness during their falls, although they didn't remember it, she adds.
Kenny began to suspect a connection between falls, blackouts and cardiovascular problems. But because people coming to the clinic were not describing blackouts to those admitting them for treatment, she wondered whether doctors might be overlooking the need for a cardiology assessment.
The standard diagnostic test for the syndrome involves having the person lie flat while a doctor massages the neck for five to 10 seconds. If nothing happens, the test is repeated with the person raised to a near-standing position.
In some people, she says, the heart slows during the carotid sinus massage but they experience no symptoms.
Kenny and her colleagues, however, wanted to know whether these people experience spontaneous pauses in their heartbeat that could have led to previously unexplainable falls.
The doctors, all from Newcastle General Hospital in Newcastle Upon Tyne, examined 175 men and women whose average age was 73, and who had gone to an emergency room because of an unexplained fall. None of the falls, the study says, had been caused by stroke, drinking, slipping or epilepsy, and all the participants in the study responded positively to the test for the syndrome.
Pacemakers, a standard treatment for a slow heart rhythm, were given to 87 participants selected randomly. For the next year, all participants kept track of any falls and other medical problems.
Falls among those with pacemakers dropped by two-thirds, and injuries by 70 percent, compared with the participants without the devices, Kenny says. Details appear in the Nov. 1 Journal of the American College of Cardiology.
"I think doctors should be thinking about a possible cardiac explanation when they see an older person who has had a fall, and not just limiting their thinking about cardiovascular disease to people who've had blackouts," Kenny says.
In a commentary accompanying publication of the research, Dr. John McAnulty calls it a landmark study.
"It raises the issue of how often is there a potentially treatable cause for the falls that would prevent recurrences," says McAnulty, the head of cardiology at the Oregon Health and Science University in Portland, Ore. "One of the potentially treatable causes is an intermittent, slow heart rhythm."
These findings suggest that slow heart rhythms are to blame for falls in some people, McAnulty says, but he adds that more research still is needed.
"There's not enough here to allow us to say that every person who comes in with a fall should have a carotid massage, and if they have a three-second pause, they should get a pacemaker," he says.
But if a person responds to the carotid massage, he adds, doctors reasonably could be more suspicious that the person is at risk of slow heart rhythms. Longer cardiac monitoring might be helpful in determining whether spontaneous slow rhythms are occurring, he says.
"[Falls are] a very huge problem in this country," McAnulty says. "If we could begin to tackle some of the potentially correctable mechanisms, it would have a significant impact."
What To Do
And, to learn more about the carotid sinus hypersensitivity syndrome, go to EMedicine.