Navigation Links
NIH-funded study finds new possible risk factor of heart disease
Date:2/15/2011

Abnormal heart rate turbulence is associated with an increased risk of heart disease death in otherwise low-risk older individuals, according to a study funded by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health.

This study appears in the Feb. 15 edition of the Journal of Cardiovascular Electrophysiology.

Among the nearly 1,300 study participants, heart rate turbulence, which reflects how well the heart reacts to occasional premature contractions, was an even stronger heart disease risk factor than elevated levels of C-reactive protein. CRP is a potential heart disease biomarker that has emerged in recent years.

Study participants considered at low risk of heart disease based on traditional risk factors were on average 8 to 9 times more likely to die of heart disease during the roughly 14-year follow-up period if they had abnormal heart rate turbulence values. Traditional risk factors include age, gender, high blood cholesterol, high blood pressure, obesity, diabetes, and smoking. Low-risk individuals with elevated CRP in their blood were about 2.5 times more likely to die than those with normal or low CRP.

"These findings suggest that apparently healthy people might be at increased risk of death from cardiovascular disease, and heart rate turbulence may help us identify them," said Susan B. Shurin, M.D., acting director of the NHLBI. "It will be important to see if we can replicate this finding in other populations."

This study followed 1,272 adults aged 65 and older as part of the NHLBI's Cardiovascular Health Study. Participants were categorized as healthy (no sign of heart disease risk except possibly diabetes), subclinical (some signs of heart disease) or clinical (had a cardiovascular event, such as a heart attack). At the onset, participants underwent 24-hour monitoring of their hearts' electrical activity through a small electrocardiographic, or ECG, device called a Holter monitor attached to their skin.

Abnormal heart rate turbulence and CRP levels both appeared to independently correlate with an increased likelihood of dying of heart disease in the group that was categorized as healthy, even after controlling for other risk factors. Abnormal heart rate turbulencepresent in about 7 percent of the study participantsalso predicted an increased likelihood of heart disease death in the subclinical and clinical groups, though these results were not as pronounced.

Heart rate turbulence refers to how smoothly the heart rate returns to normal after a premature ventricular contraction, a fairly common event in which the second portion of a heart beat is triggered too soon. Due to the improper timing between the atrial and ventricular contractions, the ventricles haven't fully filled with blood and therefore do not push out enough blood to the body. The brain detects this sub-optimal release of blood and instantly increases the heart rate to pump more blood. However, this overcompensation raises blood pressure, causing the brain to react again and lower the heart rate until blood pressure returns to normal.

By analyzing the heart's electrical signals, physicians can measure the magnitude of the initial heart rate jump (turbulence onset) and the speed at which heart rate returns to normal (turbulence slope), and then determine if the heart rate turbulence response is normal or abnormal.

"A heart rate turbulence measurement is insightful because it offers a sign of how well the autonomic, or subconscious, nervous system is functioning," said study author Phyllis K. Stein, Ph.D., a research associate professor of medicine and director of the Heart Rate Variability Laboratory at Washington University School of Medicine in St. Louis. "If someone's heart doesn't react well to these uncoordinated beats that might mean it's not good at reacting to other issues like sudden stress or severe arrhythmias."

Researchers don't yet know if abnormal heart rate turbulence can be treated or prevented. In the meantime, said Stein, interest might grow within the medical community in measuring heart rate turbulence in clinical practice. Currently, this type of measurement is not widely available.

"This study shows a great potential value for heart rate turbulence in diagnostic settings," said Robin Boineau, M.D., a medical officer in the NHLBI's Division of Cardiovascular Sciences. "It appears that signs of heart rate turbulence are also generally present a year or more before clinical manifestations of heart disease, indicating that this may be an opportunity for disease prevention in addition to disease prediction."


'/>"/>

Contact: NHLBI Communications Office
NHLBI_news@nhlbi.nih.gov
301-496-4236
NIH/National Heart, Lung and Blood Institute
Source:Eurekalert

Related medicine news :

1. NIH-funded study uses new technology to peek deep into the brain
2. In NIH-funded study, researchers uncover step in brain events leading up to addiction
3. NIH-funded study finds early HAART during TB treatment boosts survival rate in co-infected people
4. University of Mississippi Medical Center to lead in nationwide NIH-funded Alzheimers study
5. NIH-funded scientists find 2009 H1N1 pandemic influenza vaccine protects mice from 1918 flu virus
6. Motorcycle Helmets Help Protect Against Spine Injury: Study
7. Alcohol Disrupts Womens Sleep More Than Mens: Study
8. Study Links MS to Brain Chemical Deficiency
9. Kids Learn to Work Together Early, Study Finds
10. Study compares balanced propofol sedation with conventional sedation for therapeutic GI endoscopic procedures
11. Boston Medical Center critical care chief receives grant for lung injury study
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... ... of Bruton Memorial Library on June 21 due to a possible lice infestation, as reported ... head lice: the parasite’s ability to live away from a human host, and to infest ... in the event that lice have simply gotten out of control. , As lice are ...
(Date:6/25/2016)... CA (PRWEB) , ... June 25, 2016 , ... As ... with Magna Cum Laude and his M.D from the David Geffen School of Medicine ... and returned to Los Angeles to complete his fellowship in hematology/oncology at the UCLA-Olive ...
(Date:6/25/2016)... ... 25, 2016 , ... Conventional wisdom preaches the benefits of moderation, whether it’s ... setting the bar too high can result in disappointment, perhaps even self-loathing. However, those ... goal. , Research from PsychTests.com reveals that behind the tendency to ...
(Date:6/24/2016)... , ... June 24, 2016 , ... June 19, 2016 ... dangers associated with chronic pain and the benefits of holistic treatments, Serenity Recovery ... are suffering with Sickle Cell Disease. , Sickle Cell Disease (SCD) is a disorder ...
(Date:6/24/2016)... ... June 24, 2016 , ... Global law firm Greenberg Traurig, P.A. announced that ... chosen by their peers for this recognition are considered among the top 2 percent ... special honors as members of this year’s Legal Elite Hall of Fame: Miami ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016   Bay Area ... Network,s Dean Center for Tick Borne Illness ... and Rehabilitation, MIT Hacking Medicine, University of California, ... today announced the five finalists of Lyme ... disease.  More than 100 scientists, clinicians, researchers, entrepreneurs, ...
(Date:6/24/2016)... , June 24, 2016 ... the "Structural Electronics 2015-2025: Applications, Technologies, Forecasts" ... In-Mold Electronics, Smart Skin, Structural ... Structural electronics involves electronic and/or ... protective structures, replacing dumb structures such as vehicle ...
(Date:6/24/2016)... , June 24, 2016 Dehaier Medical ... the "Company"), which develops, markets and sells medical devices ... , signed a strategic cooperation agreement with Hongyuan ... "Hongyuan Supply Chain") on June 20, 2016, to develop ... the strategic cooperation agreement, Dehaier will leverage Hongyuan Supply ...
Breaking Medicine Technology: