New Electrical Abnormality Found In Heartbeat Of Heart Failure Patients

August 28, 1997

Some heart failure patients have an electrical abnormality that prevents the heart from recovering normally after each beat, Johns Hopkins physicians have discovered.

In an article published in the Sept. 2 issue of the journal Circulation, the researchers showed that although patients with heart failure maintained a steady heart rate, the ability of their hearts to recover after each beat was erratic and unstable.

"This is an important finding that requires further study clinically, to see if this is a predictor for dangerous rhythm disturbances, and mechanistically, to examine on a cellular level why this happens," says Ronald D. Berger, M.D., Ph.D., an assistant professor of medicine at Hopkins and lead author of the paper.

In the study, researchers looked at 83 patients with dilated cardiomyopathy (DCM), or heart failure, a potentially fatal form of heart disease in which the lower left chamber of the heart becomes stretched and weakened. They were compared with 60 control subjects who had no history or evidence of heart disease.

Researchers took electrocardiogram readings of each person to study the electrical activity of their heartbeats. Each heartbeat consists of three parts: the contraction of the atria (upper chambers), the contraction of the ventricles (lower chambers) and the recovery of the ventricles to their normal state.

A computer-based algorithm was then created to examine the QT interval, or time it takes for the cells of the ventricle to recover electrically from being contracted during a beat.

Results showed that in patients with DCM, the QT interval from beat to beat varied widely despite the fact that these patients had relatively stable heart rates. By contrast, in healthy patients, the QT interval from beat to beat was relatively stable, while the heart rate was more varied.

Also in healthy patients, heart rate is directly related to the QT interval. For example, if the heart rate goes up, the recovery rate is quicker. In the patients with heart disease, the coupling between heart rate and QT interval was lost.

Approximately two million Americans have heart failure. Roughly 300,000 die from it each year, half from arrhythmias.

The research was supported by two grants from the National Heart, Lung and Blood Institute and from Johns Hopkins.

The study's other authors were Edward K. Kasper, M.D.; Kenneth L. Baughman, M.D.; Eduardo Marban, M.D., Ph.D.; Hugh Calkins, M.D.; and Gordon F. Tomaselli, M.D.

--JHMI--

Media Contact: Karen Infeld (410)955-1534
E-mail: kinfeld@gwgate1.jhmi.jhu.edu


Johns Hopkins Medical Institutions' news releases are available on a PRE-EMBARGOED basis on EurekAlert at http://www.eurekalert.org and from the Office of Communications and Public Affairs' direct e-mail news release service. To enroll, call 410-955-4255 or send e-mail to bpalevic@welchlink.welch.jhu.edu or 76520.560@compuserve.com.

On a POST-EMBARGOED basis find them at http://hopkins.med.jhu.edu, http://infonet.welch.jhu.edu/news/news_releases, Newswise at http://www.ari.net/newswise or on CompuServe in the SciNews-MedNews library of the Journalism Forum under file extension ".jhm", Quadnet at http://www.quad-net.com or ScienceDaily at http://www.sciencedaily.com.

Johns Hopkins Medicine

Related Heart Disease Articles from Brightsurf:

Cellular pathway of genetic heart disease similar to neurodegenerative disease
Research on a genetic heart disease has uncovered a new and unexpected mechanism for heart failure.

Mechanism linking gum disease to heart disease, other inflammatory conditions discovered
The link between periodontal (gum) disease and other inflammatory conditions such as heart disease and diabetes has long been established, but the mechanism behind that association has, until now, remained a mystery.

New 'atlas' of human heart cells first step toward precision treatments for heart disease
Scientists have for the first time documented all of the different cell types and genes expressed in the healthy human heart, in research published in the journal Nature.

With a heavy heart: How men and women develop heart disease differently
A new study by researchers from McGill University has uncovered that minerals causing aortic heart valve blockage in men and women are different, a discovery that could change how heart disease is diagnosed and treated.

Heart-healthy diets are naturally low in dietary cholesterol and can help to reduce the risk of heart disease and stroke
Eating a heart-healthy dietary pattern rich in vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, vegetable oils and nuts, which is also limits salt, red and processed meats, refined-carbohydrates and added sugars, is relatively low in dietary cholesterol and supports healthy levels of artery-clogging LDL cholesterol.

Pacemakers can improve heart function in patients with chemotherapy-induced heart disease
Research has shown that treating chemotherapy-induced cardiomyopathy with commercially available cardiac resynchronization therapy (CRT) delivered through a surgically implanted defibrillator or pacemaker can significantly improve patient outcomes.

Arsenic in drinking water may change heart structure raising risk of heart disease
Drinking water that is contaminated with arsenic may lead to thickening of the heart's main pumping chamber in young adults, according to a new study by researchers at Columbia University Mailman School of Public Health.

New health calculator can help predict heart disease risk, estimate heart age
A new online health calculator can help people determine their risk of heart disease, as well as their heart age, accounting for sociodemographic factors such as ethnicity, sense of belonging and education, as well as health status and lifestyle behaviors.

Wide variation in rate of death between VA hospitals for patients with heart disease, heart failure
Death rates for veterans with ischemic heart disease and chronic heart failure varied widely across the Veterans Affairs (VA) health care system from 2010 to 2014, which could suggest differences in the quality of cardiovascular health care provided by VA medical centers.

Heart failure: The Alzheimer's disease of the heart?
Similar to how protein clumps build up in the brain in people with some neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, protein clumps appear to accumulate in the diseased hearts of mice and people with heart failure, according to a team led by Johns Hopkins University researchers.

Read More: Heart Disease News and Heart Disease Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.