Featured Research

from universities, journals, and other organizations

Erratic heart rhythm may account for some unexplained strokes

Date:
February 2, 2012
Source:
American Heart Association
Summary:
Occasional erratic heart rhythms appear to cause about one-fifth of strokes for which a cause is not readily established.

Occasional erratic heart rhythms appear to cause about one-fifth of strokes for which a cause is not readily established, according to research presented at the American Stroke Association's International Stroke Conference 2012.

About one-third of survivors leave the hospital with the cause of their stroke still undetermined.

"Identifying and treating these patients for irregular rhythm could reduce the recurrence of stroke by 40 percent compared to reducing the risk by treating them with aspirin," said Daniel J. Miller, M.D., the study's first author and a senior staff neurologist at Henry Ford Hospital in Detroit, Mich. "The cause doesn't make a difference if there isn't a treatment, and recently two new medications -- dabigatran and rivaroxaban -- have been approved by the FDA to treat this problem."

The study confirmed a 2008 report that found 13 of 56 patients (23 percent) whose heart rhythms were measured by automated monitors for 21 days had intermittent, or paroxysmal atrial fibrillation (PAF). Such episodes can last for a few seconds up to several days.

The 2008 study suggested that erratic beats of less than 30 seconds might indicate more prolonged episodes of PAF that lead to small blood clot formation in the hearts of patients with otherwise unidentified causes for their strokes. Since the study, stroke specialists have debated the importance of PAF to patients.

Some stroke centers, including Henry Ford Hospital, adopted the Mobile Cardiac Outpatient Monitoring™ (MCOT™) system as a method of identifying PAF.

Miller and his colleagues examined the medical records of 156 patients (half women) who had undergone monitoring no more than six months after a stroke or transient ischemic attack (TIA), most of them for 21 days. Ninety-seven percent were not taking prescription anticoagulation drugs.

Of the total, 27 patients (17.3 percent) had one or more PAF episodes during monitoring and the number increased significantly over time. In the first two days, 3.9 percent of the patients experienced an episode of PAF. The percentage rose to 9.2 percent after one week, 15.1 percent at two weeks and 19.5 percent by three weeks, after accounting for those that had stopped monitoring early.

Patients identified at study entry with premature atrial contractions -- the most common type of erratic heartbeats -- were 13.7 times more likely to have PAF than those without the rhythm problems. "That's a very high risk," Miller said.

Excluding TIA patients, the presence of premature atrial contractions in stroke survivors increased their risk of PAF to 17 times. Each one level increase in a patient's National Institutes of Health Stroke Scale increased the risk of AF by 20 percent. The 42 point scale provides physicians a standardized method to assess a patient's stroke-induced impairment.

The other risk factors applicable to stroke and TIA patients were:

  • Being female. Women in the study had 6.2 times a man's risk of PAF. In stroke patients alone, the risk was 4.6 times.
  • Having a left atrium enlarged by 1 centimeter in diameter. This finding increased the AF risk 2.3 times.
  • A reduction in blood pumped by the heart. People whose left ventricle expelled 10 percent less blood than a healthy heart had a 1.8 times risk.

"Patients with stroke of unknown origin should have at least 21 days of MCOT monitoring to reliably detect paroxysmal atrial fibrillation in order to reduce their risk of future stroke," Miller said.

Co-authors are: Muhib Khan, M.D.; Lonni Schultz, Ph.D.; Jennifer R. Simpson, M.D.; Andrew Russman, D.O.; and Mitsias Panayiotis, M.D., Ph.D.


Story Source:

The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.


Cite This Page:

American Heart Association. "Erratic heart rhythm may account for some unexplained strokes." ScienceDaily. ScienceDaily, 2 February 2012. <www.sciencedaily.com/releases/2012/02/120202094600.htm>.
American Heart Association. (2012, February 2). Erratic heart rhythm may account for some unexplained strokes. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2012/02/120202094600.htm
American Heart Association. "Erratic heart rhythm may account for some unexplained strokes." ScienceDaily. www.sciencedaily.com/releases/2012/02/120202094600.htm (accessed April 17, 2014).

Share This



More Health & Medicine News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins