Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Implanted devices detect high-risk heart failure patients


Implanted devices intended to optimize the cardiac function of patients with heart failure have provided new insights into which patients might be at higher risk of dying suddenly from their disease, according to researchers at Duke University Medical Center.

Besides maintaining optimal electrical stimulation to the heart, these CRT-D (cardiac resynchronization therapy with defibrillation) devices are giving cardiologists a new view of subtle changes in a key measurement of heart health -- heart rate variability. Patients with little variability -- whose hearts are unable to appropriately react to external stimuli by regulating their beating action -- are known to be at higher risk of suffering a heart attack. The new insight from CRT-D devices is possible because they record detailed data on heart function 24 hours a day.

These new findings are important for two reasons, the researchers said. First, the collected information appears to more accurately identify high risk patients who would benefit from early and aggressive therapy. Secondly, the devices provide cardiologists with objective information about the health status of their patients, information that can be frustratingly difficult to obtain in a typical clinical setting in this medically diverse group of patients, the researchers said.

The results of the study were presented by Duke cardiologist Roosevelt Gilliam, M.D., March 7, 2005, at the annual scientific session of the American College of Cardiology in Orlando. "When you talk to heart failure patients, many times their perceptions of how they feel do not match with their actual clinical status, which can make it difficult for cardiologists to get a true idea of how the disease is progressing," said Gilliam, chief of electrophsysiology at Duke. "This study shows that changes in heart rate variability just might be better in picking out those people at highest risk."

In their analysis of 1,411 heart failure patients who received the CRT-D device, the researchers found a strong correlation between the heart rate variability changes within two weeks of implantation and mortality one year later.

"This approach may play a significant role in targeting a subset of heart failure patients for whom we need to be more aggressive if we don’t see early improvement in heart rate variability," Gilliam said. "We would expect that as their heart function improves after implantation, their heart rate variability would improve as well."

Heart failure is a condition marked by the inability of the heart muscles to pump enough oxygen and nutrients in the blood to the body’s tissues. Also known as congestive heart failure, its many causes include infections of the heart, coronary artery disease, high blood pressure, previous heart attacks and valve problems. An estimated 4.7 million Americans suffer from the condition, with 400,000 new cases reported each year. Roughly one-half of patients die within five years of diagnosis.

Although there is no cure, drugs can improve the strength of the heartbeat (digoxin), relax blood vessels (ACE inhibitors)or remove the excess buildup of fluid in the lungs (diuretics). Implantable devices are the latest options in preventing arrhythmias that can lead to sudden death, with CRT-Ds being the latest technology.

CRT-Ds perform two main functions. First, the devices electrically stimulate both sides of the heart in coordinated fashion, which optimizes the contractability of already weakened heart muscle. Second, the defibrillator "shocks" the heart back into normal rhythm whenever the heart beats irregularly.

In addition to maintaining the heart, the devices also collect heartbeat-by-heartbeat data that can be downloaded from the device and entered into a computer. One use of the data in this trial was to create a "footprint," or visual representation, of a patient’s heart rate variability over time. Patients with a footprint of 30 percent or less in heart rate variability were almost two-and-half times more likely to die after one year.

"A person with normal heart rate variable would have a very wide footprint, while those with sick hearts would have a narrow footprint that represents the reduced variance in heart rate response," Gilliam explained. "These footprints provide us with an unbiased – distinct from the patient’s perception – look at how the patient is truly doing. It is an objective finding that you can look at and easily understand."

Gilliam pointed out that the cardiologists are "in uncharted waters" when it comes to the new devices, their role in the treatment of heart failure, and how to make best use of the new data which they can provide. Additional trials will be needed to tease out the relationships between different patient characteristics, the use of the new technology, and patient outcomes, Gilliam said.

Richard Merritt | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>