Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nervous system’s role in fatal heart rhythm studied

23.12.2005


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.”

Jennifer Hilliard | EurekAlert!
Further information:
http://www.mcg.edu

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>