William Atkins
Tuesday, 24 February 2009 22:05
Science -
Health
Page 2 of 4
If the emergency lasts for more than a few seconds, the blood will stop circulating throughout the body and death may occur within a few minutes—that is, of course, unless a defibrillator is used on the body from an outside source or an internal defibrillator detects the emergency and provides a fast electrical shock to the system.
The T-wave is the last recorded indication (upswing mark) on an ECG, which records the electrical activity of a beating heart.
T-wave alternans has been shown in past studies to cause an increased risk for potentially deadly heart arrhythmias in people already with heart problems.
However, such emergencies, and sometimes those resulting deaths, caused by irregular heartbeats can be prevented by the implantation of a defibrillator, which forces the heart to beat in a regular manner.
Therefore, the researchers wanted to determine if TWA produced by anger—within a laboratory setting—could predict ventricular arrhythmias (commonly called irregular heartbeats) in the heart of patients with implantable
cardioverter-defibrillators (ICDs)—usually called implanted defibrillators.
Therefore, the U.S. researchers studied 62 patients with defibrillators implanted in their chests because of already-existing heart disease and conditions. The patients had an
“ambulatory electrocardiography during a mental stress protocol” three months after the ICD was implanted. [Paper]
Later, the patients had their T-wave alternans (TWA) detected by a mental stress test. The researchers had them remember a past event that angered or maddened them, which showed up on an ECG as a point indicating the TWA.
Page three continues with conclusions from the U.S. researchers.
