Featured Research

from universities, journals, and other organizations

Role Of Nervous System In Fatal Heart Rhythm Under Study

Date:
January 2, 2006
Source:
Medical College of Georgia
Summary:
Finding out why seemingly healthy people experience ventricular fibrillation, a fatal irregular heart rhythm, could eventually lead to better methods of early detection, according to a Medical College of Georgia researcher.

Dr. Autumn Schumacher is studying the role of adrenaline on ventricular fibrillation.
Credit: Photo by Jon Rou, Georgia Institute of Technology

Finding out why seemingly healthy people experience ventricular fibrillation, a fatal irregular heart rhythm, could eventually lead to better methods of early detection, according to a Medical College of Georgia researcher.

“We don’t know what starts ventricular fibrillation or why defibrillation – electrically shocking the heart back into beating normally – works to correct it,” says Dr. Autumn Schumacher, a new faculty member in the MCG School of Nursing who recently won the American Heart Association’s Martha N. Hill New Investigator Award for her research. “We do, however, need a better understanding of this abnormal rhythm and its subtle warning signals so that we can develop smarter bedside monitors.”

While the condition is more common in people with undiagnosed heart problems, those who’ve had a previous heart attack and those with coronary artery disease, it also happens to seemingly healthy people when the body is under stress and secreting adrenaline, says Dr. Schumacher, a physiological and technological nursing professor.

Her current research focuses on what effect adrenaline has on the electrical patterns in the heart.

“The autonomic nervous system controls the heart rate by signaling our body to secrete adrenaline and increase our heart rate based on what we need – the fight or flight reflex,” she says.

Researchers already know that ventricular fibrillation occurs when the heart’s electrical system malfunctions, the electrical signals that control the pumping of the heart become rapid and chaotic causing the lower chambers of the heart to quiver instead of contract. Those chambers can no longer pump blood to the rest of the body, which leads to sudden cardiac death without defibrillation – a successful emergency shock to jump start the heart back into a regular beat.

Studying those electrical signals is what will lead to better medical equipment, Dr. Schumacher says.

Traditional cardiac tests such as electrocardiograms, which record the electrical activity of the heart and identify abnormal rhythms, and echocardiograms, which use sound waves to create a moving picture of the heart, haven’t been able to pinpoint minute changes that are a precursor to ventricular fibrillation; they only provide a picture of large scale electrical activity.

But, by using voltage-sensitive fluorescent dye, injecting it into an isolated animal model and photographing the images at 1,000 frames per second, researchers have been able to see the small picture. These minute images of ventricular fibrillation have recently led to the discovery that the electrical activity during ventricular fibrillation forms distinct patterns.

“The patterns aren’t random as we previously thought,” Dr. Schumacher says. “They actually form spiral waves that often collide with each other and spin off more spiral waves.”

Better bedside monitors will be able to detect the precursors to those spiral wave patterns so that doctors and nurses will have a two-to-three minute warning and can prevent ventricular fibrillation before it happens, she says.

To find out what role adrenaline plays in the whole process, Dr. Schumacher uses various drugs to simulate autonomic nervous system imbalance in an isolated animal heart. Then she photographs fluorescent images of the electrical activity while recording the heart’s rhythm with an electrocardiogram.

“We know that autonomic imbalance and too much adrenaline can contribute to the conditions promoting ventricular fibrillation,” she says. “This research aims to find out why.”


Story Source:

The above story is based on materials provided by Medical College of Georgia. Note: Materials may be edited for content and length.


Cite This Page:

Medical College of Georgia. "Role Of Nervous System In Fatal Heart Rhythm Under Study." ScienceDaily. ScienceDaily, 2 January 2006. <www.sciencedaily.com/releases/2005/12/051224093845.htm>.
Medical College of Georgia. (2006, January 2). Role Of Nervous System In Fatal Heart Rhythm Under Study. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2005/12/051224093845.htm
Medical College of Georgia. "Role Of Nervous System In Fatal Heart Rhythm Under Study." ScienceDaily. www.sciencedaily.com/releases/2005/12/051224093845.htm (accessed September 17, 2014).

Share This



More Health & Medicine News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Study Links Male-Pattern Baldness To Prostate Cancer

Study Links Male-Pattern Baldness To Prostate Cancer

Newsy (Sep. 16, 2014) New findings suggest men with a certain type of baldness at age 45 are 39 percent more likely to develop aggressive prostate cancer. 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