Featured Research

from universities, journals, and other organizations

"Swing" Test May Identify Those At Highest Risk Of Death From Congestive Heart Failure

Date:
October 13, 1998
Source:
American Heart Association
Summary:
A new test that measures swings in heart rate during the day may help identify individuals with congestive heart failure who are at the highest risk of dying from the condition within a year, according to a study in Circulation: Journal of the American Heart Association.

DALLAS, Oct. 13 -- A new test that measures swings in heart rate during the day may help identify individuals with congestive heart failure who are at the highest risk of dying from the condition within a year, according to a study in today's Circulation: Journal of the American Heart Association. Congestive heart failure (CHF) occurs when the heart muscle becomes unable to pump enough blood to meet the needs of the body's other organs. The test measures heart rate variability (HRV), the amount by which the heart rate changes from slow rates to fast rates in one 24-hour period. "The less the heart rate varies over 24 hours, the more likely a person will die of congestive heart failure," says the study's lead author James Nolan, M.D., consultant cardiologist at the Cardiology Center, North Staffordshire Hospital in Staffordshire, England.

In the study, people with the lowest HRV whose fastest heart rate was not much different from their slowest heart rate were three times more likely to die than individuals with the highest HRV. The annual death rate of people with the lowest HRV was 51.4 percent compared to 5.5 percent for those with the highest HRV. People whose HRV was between the two extremes had an annual death rate of 12.7 percent. The test can offer physicians a warning when people are at risk for early death and need intense treatment to save their lives, he says. "The take-home message to doctors is to measure the HRV in their patients with congestive heart failure. If it's high, the person is going to do well. If it's low, he or she is quite likely to die soon and the doctor should adjust treatment to try to prevent that," says Nolan.

"The HRV test will allow physicians to target extra treatment to the 40 percent of patients most likely to benefit. The money saved by not treating low-risk patients can then be allocated to other areas of health care," he says. The report is a follow-up investigation to previous studies indicating that a low HRV soon after a heart attack reduces a person's chance of survival. "There were reasons to think that if HRV is predictive following a heart attack, it might be even more valuable for heart failure patients," Nolan says.

For the study, the scientists selected 433 people in the United Kingdom Heart Failure Evaluation and Assessment of Risk Trial (UK-HEART) with symptoms of severe heart disease. The participants' average age was 62. Heart electrical activity was recorded by a small portable electrocardiograph (ECG) worn by each participant for a full day. Participants were able to continue with their normal daily activities throughout the recording period. The taped ECGs were run through an automatic analyzer that excluded abnormal beats and determined the variability in the 24-hour recording period. Participants were followed for an average of 482 days after their monitoring. Fifty-four deaths occurred during this time, with a total death rate of 9.5 percent.

The HRV is a good way to identify patients who are more likely to die of congestive heart failure. It can be used in conjunction with other measurements such as chest x-ray, blood tests or heart ultrasound examinations, says Nolan. Low HRV may be due to a defect in the autonomic nervous system -- the part of the nervous system that regulates "involuntary" body functions such as breathing and the beating of the heart, says Nolan. "The autonomic nervous system is constantly adjusting the rate at which the heart beats. Those people with the sickest hearts can't do that, so they have very little variability in their heart rate," says Nolan.

"If part of your heart is damaged and functioning inadequately, quality of life is maintained at the expense of overworking the surviving parts of your heart. There are no 'down' times where the heartbeat can slow down, allowing the heart to rest," he says. "And that may lead to a downward spiral of declining heart function and death from congestive heart failure. "Drugs like beta blockers, digoxin, and scopolamine -- a drug used to treat travel sickness that affects the autonomic nervous system -- and simple things like exercise training improve heart rate variability," Nolan says. "These beneficial effects may prevent heart function from deteriorating and keep individuals alive for longer."

Nolan and his colleagues have planned more studies to test the effectiveness of various treatments in prolonging the lives of people with congestive heart failure with low HRV. CHF, which is increasing dramatically in the U.S. population, can be caused by conditions including, but not limited to, high blood pressure, scar tissue from prior heart attacks and coronary heart disease that narrows the vessels that supply blood to the heart muscle. About 4.9 million Americans have CHF. Co-authors are Phillip Batin, M.D.; Steven Lindsay, M.R.C.P.; Richard Andrews, M.R.C.P.; Paul Brooksby, M.D.; Michael Mullen, M.R.C.P.; Wazir Baig, M.D.; Andrew Flapan, M.D.; Alan Cowley, F.R.C.P.; Robin Prescott, Ph.D.; James Neilson, Ph.D.; and Keith Fox, F.R.C.P.


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. ""Swing" Test May Identify Those At Highest Risk Of Death From Congestive Heart Failure." ScienceDaily. ScienceDaily, 13 October 1998. <www.sciencedaily.com/releases/1998/10/981013074836.htm>.
American Heart Association. (1998, October 13). "Swing" Test May Identify Those At Highest Risk Of Death From Congestive Heart Failure. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/1998/10/981013074836.htm
American Heart Association. ""Swing" Test May Identify Those At Highest Risk Of Death From Congestive Heart Failure." ScienceDaily. www.sciencedaily.com/releases/1998/10/981013074836.htm (accessed July 22, 2014).

Share This




More Health & Medicine News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
Powered by NewsLook.com
Tooth Plaque Provides Insight Into Diets Of Ancient People

Tooth Plaque Provides Insight Into Diets Of Ancient People

Newsy (July 19, 2014) Research on plaque from ancient teeth shows that our prehistoric ancestor's had a detailed understanding of plants long before developing agriculture. Video provided by Newsy
Powered by NewsLook.com
Contaminated Water Kills 3 Babies in South African Town

Contaminated Water Kills 3 Babies in South African Town

AFP (July 18, 2014) Contaminated water in South Africa's northwestern town of Bloemhof kills three babies and hospitalises over 500 people. The incident highlights growing fears over water safety in South Africa. Duration: 02:22 Video provided by AFP
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