Researchers conducting a large, ongoing study to improve detection and prevention of sudden cardiac death were surprised to discover that a specific heart rhythm abnormality – idiopathic QT interval prolongation – increased risk five-fold among patients with coronary artery disease.
“More than 80 percent of all cases of sudden cardiac death occur in people who have significant coronary artery disease, but we currently do not have a medical test that consistently identifies patients at risk,” said Sumeet S. Chugh, M.D., associate director of the Cedars-Sinai Heart Institute and director of Clinical Electrophysiology. Chugh is first author of an article in Circulation, now appearing online ahead of print. This research was conducted with colleagues in the Emergency Medicine and Pathology Departments at Oregon Health and Science University in Portland, as part of the ongoing Oregon Sudden Unexpected Death Study.
“Abnormal QT prolongation has significant potential for evaluating risk and developing prevention strategies, but there are many factors – some known and some not known – that contribute to QT prolongation. Diabetes and the use of certain medications were significant predictors of QT interval prolongation and sudden cardiac death risk in our study. However, the most interesting and somewhat unexpected finding was that abnormally prolonged QT interval of unknown etiology – independent of diabetes, medications and other factors – was an even more powerful predictor of sudden cardiac death, with a five-fold increase in odds,” said Chugh, who holds the Pauline and Harold Price Chair in Cardiac Electrophysiology Research.
The researchers noted that several gene variations have been linked to prolonged QT intervals, and the discovery of new genetic associations are likely to improve risk-assessment and intervention strategies. “The continued identification of gene variants that determine QT interval duration has become an important scientific priority in the field,” Chugh said.
“QT interval” refers to electrical activity that occurs in the main pumping chambers of the heart, the ventricles. It includes the Q, R, S, and T waves seen on an electrocardiogram. Unlike heart attacks, which are typically caused by clogged coronary arteries, sudden cardiac arrest is the result of defective electrical impulses.
In 2002, Chugh launched the Oregon Sudden Unexpected Death Study, an ambitious population study involving 16 hospitals serving a community of about 1 million residents in the Portland, Ore., metropolitan area. This and related research projects are continuing to shed light on the incidence, demographics, genetic defects, risk factors, triggers and prevention techniques related to sudden cardiac arrest, which causes nearly instantaneous death in 90 percent of cases.
Chugh directed the Cardiac Arrhythmia Center at Oregon Health and Science University prior to joining Cedars-Sinai in late 2008. This study was funded by the National Institutes of Health/National Heart, Lung, and Blood Institute and a Hopkins-Reynolds Clinical Cardiovascular Center grant.
Citation: Circulation, “Determinants of Prolonged QT Interval and Their Contribution to Sudden Death Risk in Coronary Artery Disease: The Oregon Sudden Unexpected Death Study,” published online ahead of print Jan. 26, 2009.
Further reports about: > Cardiac Electrophysiology Research > Cedars-Sinai > Diabetes > Disease > Electrophysiology > Genetic Defects > Heart > Idiopathic QT interval prolongation > QT prolongation > Rhythm abnormality > artery disease > cardiac > cardiac arrest > coronary artery disease > death > demographics > heart disease > risk factor > sudden death risk
Second cause of hidden hearing loss identified
20.02.2017 | Michigan Medicine - University of Michigan
Prospect for more effective treatment of nerve pain
20.02.2017 | Universität Zürich
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
20.02.2017 | Materials Sciences
20.02.2017 | Health and Medicine
20.02.2017 | Health and Medicine