and Medicine for Seniors
Test Reveals Genetic Risk of Atrial Fibrillation and Stroke
half of the people with AFib are seniors age 75 or older
Oct. 3, 2014 – Atrial fibrillation, which causes an irregular heartbeat,
can lead to a number of health risks, including heart disease and
Developing AFib increases
markedly with older age, with about half of those with the condition are
senior citizens over age 75. The American Heart Association points out
people are more likely to get the condition if a family member has it.
New research, however, has discovered how to identify
with a simple blood test those who are genetically predisposed to
develop atrial fibrillation and possibly a stroke.
“About three out of four people who have a
the first time have
high blood pressure.
And an irregular atrial heart rhythm -
- is present in about one out of five strokes,” according to the
“Stroke is the nation’s No. 4 killer. It happens when a blood vessel
that supplies blood to the brain is blocked or bursts. Nearly 800,000
Americans suffer a stroke each year. High blood pressure is the chief
culprit, and atrial fibrillation isn’t far behind.”
The number of people affected by atrial fibrillation is rising rapidly,
partly as a result of the aging population.
Over recent years, a research group at Lund University in Sweden,
working with other universities and hospitals in Europe and the USA, has
identified twelve genetic variants in the human genome that increase the
risk of atrial fibrillation. The research group has now studied the
possible clinical benefits of a DNA test:
"One in five people have a genetic weakness that means they have twice
as high a risk of developing atrial fibrillation as those with a low
genetic risk. This genetic risk is therefore one of the strongest risk
factors for atrial fibrillation that we know of in people without overt
cardiac disease. It increases the risk as much as high blood pressure,
for example", said Olle Melander, Professor of Internal Medicine, and
Gustav Smith, Associate Professor in Cardiology, both from Lund
Since the symptoms of atrial flutter can be weak and unclear, they are
sometimes difficult to pick up. However, even those with weak or absent
symptoms of atrial flutter are at significantly higher risk of stroke.
"In patients who are suspected of having temporary but recurrent
episodes of atrial fibrillation, or in people with high blood pressure,
it can be important for doctors to look at their genetic predisposition
using a blood test. The test can give guidance as to how often and how
intensively doctors need to screen for presence of atrial fibrillation
in these individuals. We also consider that more widespread treatment of
high blood pressure may be justified in those with a high genetic risk
of atrial fibrillation", explained Melander.
Patients already diagnosed with atrial fibrillation were also studied,
and the researchers observed that if they had the risk genes, their risk
of stroke was increased by a further 70–80 per cent.
If an individual with atrial fibrillation is regarded as having a
sufficiently high stroke risk, lifelong treatment with anticoagulant
drugs such as warfarin is required in order to lower the risk.
"There are also benefits of checking the genetic risk of those who have
already been diagnosed with atrial fibrillation. The test makes it
easier to correctly assess whether anticoagulant medication is necessary
to prevent stroke, especially for those under 65", said Olle Melander.
The research data was taken from a long-term follow-up of 27,400
participants in a population study.
"The present results are one of several examples of how genetics
research is not only an effective way of identifying new disease
mechanisms, but can also have clinical applications and help doctors and
patients to decide on the right tests and treatment", said Olle Melander.
The research was funded by, among others, the Swedish Heart-Lung
Foundation, the Swedish Research Council and the EU. The findings were
published recently in the American journal Stroke.
An arrhythmia is a problem with the speed or rhythm of the heartbeat.
Atrial fibrillation (AF) is the most common type of
arrhythmia. The cause is a
disorder in the heart's electrical system.
Often, people who have AF may not even feel symptoms. But you may feel
>> Palpitations -- an abnormal rapid heartbeat
>> Shortness of breath
>> Weakness or difficulty exercising
>> Chest pain
>> Dizziness or fainting
AF can lead to an increased risk of
In many patients, it can also cause chest pain,
Doctors diagnose AF using family and medical history, a physical exam,
and a test called an electrocardiogram (EKG), which looks at the
electrical waves your heart makes. Treatments include medicines and
procedures to restore normal rhythm.
NIH: National Heart, Lung, and Blood
Atrial Fibrillation and Stroke
(National Institute of Neurological Disorders and Stroke)
Device Interventions for Stroke Prevention
in Atrial Fibrillation (American Heart Association)
High Blood Pressure, Afib and Your Risk of
Stroke (American Heart Association)
Stroke Prevention in Atrial Fibrillation
(American Heart Association)