Memory loss might start with this common heart rhythm disturbance

Kathleen Blanchard's picture
Alzheimer's could begin with common heart rhythm problem, finds new research.

Atrial fibrillation (AF) that causes the heart to beat irregularly is found in a new study to hasten memory problems, researchers find. The condition is the most common type of heart rhythm problem that is expected to affect 12 million people by the year 2050, according to statistics from the Centers for Disease Control.

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How atrial fibrillation could cause loss of memory

Atrial fibrillation causes the upper and lower heart chambers to beat in an uncoordinated fashion. The result is decreased blood flow throughout the body. A common complication is blood clot that can lead to stroke.

Because stroke is a common complication of atrial fibrillation that can lead to memory problems Evan Thacker, Ph.D., a statistician in the Department of Epidemiology at University of Alabama at Birmingham (UAB) School of Public Health decided to explore whether people with the abnormal heart rhythm who did not have a stroke might also prone to memory problems.

The findings showed cognitive decline happens more quickly for people diagnosed with atrial fibrillation, even after taking into account age and other known risk factors for memory loss. Past studies have also linked a fib to Alzheimer's and dementia.

Thacker said memory issues might accompany the coming heart rhythm disturbance for two reasons:

  • The brain may not get the oxygen it needs, in turn leading to cognitive decline that happens over time
  • Small blood clots might form that get lodged in the brain’s blood vessels

"Currently, we do not know whether either of these two possibilities actually occurs," he said. "We would like to study it using brain imaging technology to learn more about what is happening in the brains of people with atrial fibrillation."

The heart rhythm disturbance can cause clots to form when blood sits in the heart. The asynchronous activity of the heart means not all of the blood is squeezed out into circulation with each heartbeat, which also could be the cause of oxygen deprivation to the brain suspected to lead to poor memory and even dementia.

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The upper chambers known as the atrium contract; then the lower chambers or ventricles may contract before they are completely filled with blood. There can be long pauses before the contraction happens.

The treatment to prevent clots is blood thinners like warfarin or Xarelto. Sometimes the heart can be ‘shocked’ back in a normal rhythm. Another option for atrial fibrillation treatment is called ablation. A specialized cardiologist ‘maps’ the heart’s signals during a procedure much like a cardiac catheterization and ‘ablates’ the pathways sending the signals causing the rhythm disturbance. Sometimes a pacemaker is needed.

The study

For the study researchers analyzed data from 5,000 people aged 65 and older who took part in the Cardiovascular Health Study, none of whom had atrial fibrillation at the beginning of the investigation.

Over seven year period, 550 people developed the heart rhythm disturbance. The study participants underwent a 100 point test each year to assess thinking and memory.

Compared to people without atrial fibrillation, those that had been diagnosed were more likely to experience memory problems and at an earlier age. The study is published in the journal Neurology.

The goal of the researchers is to understand why atrial fibrillation that is a common heart rhythm disturbance leads to memory loss so they can find ways to prevent it.

Image credit: Photobucket

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