About Careers MedBlog Contact us

Irregular Heartbeats Could Cause Unexplained Strokes

by VR Sreeraman on February 3, 2012 at 9:02 PM
Font : A-A+

 Irregular Heartbeats Could Cause Unexplained Strokes

Researchers have found the clue behind some unexplained strokes. According to the research erratic heart rhythms is said to be the culprit behind one-fifth of strokes.

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.

Source: Eurekalert


Recommended Reading

Latest Research News

Learn How Brain Processes Your Daily Life
Studies using brain scans shows that how our brain helps us experience and remember our daily surroundings.
Fish's Sense may Help Restore Spinal Cord Injury Deficits
Scientists explore a potential mechanism that a jawless fish called the lampreys employs to swim again after spinal cord injuries.
Lesbian, Gay, And Bisexual (LGB) Preteens Unveil Higher Social Media Addiction
New study finds that lesbian, gay, and bisexual (LGB) preteens exhibit more social media and mobile phone addiction than straight peers.
Brain Region Linking Short-term to Long-term Memory Discovered
The model for memory consolidation claims that the hippocampus forms new memories and, as time goes on, trains the cortex to store enduring memories.
What Are the Effects of T Cells on Blood Pressure and Inflammation?
A new study explored the link between T immune cells in ill patients and mortality risk.
View All
This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close

Irregular Heartbeats Could Cause Unexplained Strokes Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests