Routine electrocardiograms predict health risks for patients with atrial fibrillation

October 28, 2012, Heart and Stroke Foundation of Canada

Canadian scientists have determined that routine electrocardiogram (ECG) results for patients with atrial fibrillation (AF)—the most common form of irregular heart beat—can help doctors identify those at higher risk of adverse cardiovascular outcomes, including death. This knowledge will help doctors improve the treatment and prognosis of atrial fibrillation.

Through a retrospective analysis of thousands of patient files, researchers at the Montreal Heart Institute and the University of Calgary learned that a routine 12-lead surface ECG—in which 12 different are recorded—conducted at the time of AF diagnosis is an accurate predictor of later adverse events.

Research presented today at the Canadian Cardiovascular Congress found that patients with AF do not all face the same risks for disease; determining the extent to which any individual patient is at risk of adverse events has been a challenge for doctors, until now.

"The ECG has recently received resurging attention due to its simplicity, relatively cheap cost and near universal availability," says Dr. Jason Andrade, cardiologist at the Montreal Heart Institute. "This knowledge, combined with the recognition that all patients with AF will receive an ECG as part of their diagnostic work-up, makes it highly useful as a method for assessing risk."

ECG is used to measure the rate and regularity of heartbeats, as well as the size and position of the chambers, the presence of any damage to the heart and the effects of drugs or devices used to regulate the heart, such as a pacemaker

Researchers found that the strongest indicators of risk were prolonged QRS duration and prolonged PR and QT intervals, each of which is a measure of electrical waves that regulate heart rhythm.

For example, a prolonged QRS duration is associated with an increased risk of multiple adverse cardiovascular outcomes including death and hospitalization.

An increased PR interval is associated with and sudden cardiac death. A prolonged corrected QT interval is associated with an increased risk of cardiovascular hospitalization and sudden arrhythmic death in men.

Dr. Andrade noted that the research team was "somewhat surprised at the strength of the relationship between the identified ECG predictors and the adverse cardiovascular outcomes."

Their data analysis showed that a prolonged QRS duration was associated with a 40 per cent increased risk for all-cause mortality, a 50 to 60 per cent increased risk for cardiovascular mortality and a 90 to 120 per cent increased risk for sudden cardiac death.

It is estimated that 350,000 Canadians live with AF, and that rate is likely climbing as the population ages. Those with AF are three to five times more likely to suffer a stroke, the majority of which are disabling and are more likely to be fatal. However, prevention is effective at reducing the risks associated with AF.

(AF), a type of irregular heart rhythm known as an arrhythmia, can cause the heart to beat very fast, sometimes more than 150 beats per minute. While it is rare in people under 40, its prevalence increases with age.

"Knowing that the risk of developing AF increases with age and with other risk factors such as diabetes, high blood pressure and underlying heart disease, it is important to take action by following a healthy lifestyle to start reducing your risk," says Heart and Stroke Foundation spokesperson Dr. Beth Abramson. "Your risk for developing many diseases can be reduced if your diet is lower in sodium, saturated and trans fats and includes plenty of vegetables, fruit and whole grains."

She says that if you have a tendency to high blood pressure—which is associated with AF—then regular activity, watching salt in your diet and maintaining a healthy body weight are especially important preventive measures.

Dr. Abramson also recommends being tobacco-free, limiting alcohol intake and reducing stress as much as possible. "Any lifestyle changes that lower blood pressure may reduce your chances of developing AF," she adds.

Explore further: The Medical Minute: Atrial Fibrillation -- What is It?

Related Stories

The Medical Minute: Atrial Fibrillation -- What is It?

October 6, 2011
Atrial fibrillation (AF) is the most common heart rhythm disturbance in the United States and affects 2 to 4 million Americans. It is usually a disease of aging, however it can affect people of all ages -- 1 percent of people ...

Palpitations are predictive of future atrial fibrillation: large population study

May 15, 2012
A large cohort study has found that the strongest risk factors for atrial fibrillation in both men and women were a history of palpitations and hypertension. While hypertension is a well known risk factor for AF, the investigators ...

The big risk factor for stroke that you may not know you have

September 15, 2011
A cardiac condition called atrial fibrillation, the most common cardiac arrhythmia, can increase your risk of stroke by 500 percent. That's why Anne B. Curtis, MD, Charles and Mary Bauer Professor and Chair of the University ...

Atrial fibrillation associated with increased risk of death and cardiovascular events in women

May 24, 2011
Researchers at Brigham and Women's Hospital (BWH) have found that among women who are mostly healthy, those diagnosed with atrial fibrillation have an increased risk of death when compared to women without atrial fibrillation. ...

Recommended for you

A nanoparticle inhalant for treating heart disease

January 18, 2018
A team of researchers from Italy and Germany has developed a nanoparticle inhalant for treating people suffering from heart disease. In their paper published in the journal Science Translational Medicine, the group describes ...

Starting periods before age of 12 linked to heightened risk of heart disease and stroke

January 15, 2018
Starting periods early—before the age of 12—is linked to a heightened risk of heart disease and stroke in later life, suggests an analysis of data from the UK Biobank study, published online in the journal Heart.

'Decorated' stem cells could offer targeted heart repair

January 10, 2018
Although cardiac stem cell therapy is a promising treatment for heart attack patients, directing the cells to the site of an injury - and getting them to stay there - remains challenging. In a new pilot study using an animal ...

Two simple tests could help to pinpoint cause of stroke

January 10, 2018
Detecting the cause of the deadliest form of stroke could be improved by a simple blood test added alongside a routine brain scan, research suggests.

Exercise is good for the heart, high blood pressure is bad—researchers find out why

January 10, 2018
When the heart is put under stress during exercise, it is considered healthy. Yet stress due to high blood pressure is bad for the heart. Why? And is this always the case? Researchers of the German Centre for Cardiovascular ...

Heart-muscle patches made with human cells improve heart attack recovery

January 10, 2018
Large, human cardiac-muscle patches created in the lab have been tested, for the first time, on large animals in a heart attack model. This clinically relevant approach showed that the patches significantly improved recovery ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.