Simple Test Identifies Whos at High Risk After a Heart Attack
Reported December 05, 2007
(Ivanhoe Newswire) A two-in-one test may help save the lives of heart attack patients.
New research from the University of Calgary, Canada shows two results from one simple test makes it much more likely for doctors to identify patients who have the greatest risk of cardiac arrest or death, even years after they have a heart attack. The test lets doctors look at both the nervous system and the hearts electrical system.
The REFINE study (Risk Estimation Following Infarction, Noninvasive Evaluation) examined two critical factors that can cause serious cardiac arrhythmias. An electrical system damaged by a heart attack can lead to serious disturbances in the hearts rhythm; and a nervous system on high alert makes a patient more likely to have a serious arrhythmia that will progress to cardiac arrest and death.
322 patients who had a heart attack and had at least a mild abnormality in the hearts pumping ability took part in the study. Participants wore a heart monitor for 18 to 24 hours a day. Researchers looked for abnormalities in the hearts rhythm called T-wave alternans (TWA) and checked to see if the nervous system was on high alert by looking for abnormalities in heart rate turbulence (HRT) a measure of the hearts ability to adapt to change.
Results shows the 20-percent of patients who had both TWA and impaired HRT on the heart monitor as well as a persistent abnormality in the hearts pumping ability had more than six times the risk of cardiac arrest or death compared to other participants.
Studies are expected to begin in 2008 to look at whether an implantable defibrillator can save the lives of patients with abnormalities in both the nervous system and the hearts electrical system.
SOURCE: Journal of the American College of Cardiology, 2007;