A new US study suggests that learning to manage your anger might save your life: they found that anger-induced electrical changes can predict future heart arrhythmias in patients with implantable cardioverter-defibrillators (ICDs).
The study is the work of researchers at Yale University School of Medicine in New Haven, and the Veterans Affairs Connecticut Healthcare System in West Haven, Connecticut, and at PinMed Inc. and University of Pittsburgh, Cardiovascular Institute, Pittsburgh, Pennsylvania, and is published in the March 3rd issue of the Journal of the American College of Cardiology.
Lead author Dr Rachel Lampert, associate professor at Yale University School of Medicine told the press that the study was important because:
“We are beginning to understand how anger and other types of mental stress can trigger potentially lethal ventricular arrhythmias, especially among patients with structural heart abnormalities.”
“We know strong emotion increases sympathetic arousal,” explained Lampert.
“In this study, we found patients with higher levels of anger-induced TWA [a measure of the heart’s electrical stability] were more likely to experience arrhythmias requiring ICD termination,” she added.
Findings from other studies show that at times of great stress in the population, such as when there is an earthquake or war, there are more sudden cardiac deaths.
This study is the first to show that changes brought on by anger and other strong emotions can anticipate arrthymias and link mental stress to sudden cardiac arrest.
Sudden cardiac arrest is when the heart unexpectedly suddenly stops beating, causing blood to stop flowing to the brain and other vital organs.
According to the National Heart, Lung and Blood Instititue (NHLBI), every year between 250,000 and 450,000 Americans have sudden cardiac arrest. It occurs most often in people in their mid-thirties to mid-forties and appears to affect men twice as often as women.
For this study, Lampert and colleagues examined 62 patients fitted with ICDs because they either had coronary artery diseae or dilated cardiomyopathy, a condition where the heart muscle is enlarged. They were all recruited from the Yale Electrophysiology practice.
They monitored the patients as they underwent a mental stress test in the laboratory about 3 months after being implanted with the ICD. During the test patients were asked to remember a recent situation that made them feel angry or aggravated. While the patients recalled their anger incident, the researchers monitored their T-wave alternans (TWA), a measure of their heart’s electrical stability.
After this the patients were followed for an average of 37 months to see which of them had arrthymias that had to be stopped by their implanted ICDs.
The results showed that 16 per cent of the patients had ICD-terminated arrhythmias during follow up, and these also had higher TWA induced by anger than those patients who did not have arrhythmias during follow up.
Even when they took other clinical factors into account that might predispose patients to higher levels of TWA or higher levels of heart events (eg heart failure or history of arrhythmia), the researchers found that anger-induced TWA remained a significant predictor of arrhythmia during follow up. The risk was ten times that of other patients.
The authors recommended screening based on accurate non-invasive risk tests to identify patients at greatest risk for life-threatening arrhythmia, since these findings suggest that mental stress, and anger in particular, may be another route that provokes arrhythmia.
Commenting in an accompanying editorial, Dr Eric J. Rashba, professor of Medicine at Stony Brook University Medical Center, Long Island, New York, wrote:
“What remains unclear is how this new T-wave alternans test relates to traditional exercise TWA testing.”
“It may be that combining exercise TWA tests with newer mental stress TWA tests may help clinicians better select patients likely to have arrhythmia and, in turn, benefit from a defibrillator; however, more study is needed,” he added.
Lampert said that unlike exercise, mental stress doesn’t raise heart rate significantly, which suggests that mental stress may affect heart tissue directly via adrenaline. Thus mental stress tests could be an alternative to atrial pacing for patients who can’t exercise, she added, stressing that:
“More research is needed, but these data suggest that therapies focused on helping patients deal with anger and other negative emotions may help reduce arrhythmias and, therefore, sudden cardiac death in certain patients.”
“Anger-Induced T-Wave Alternans Predicts Future Ventricular Arrhythmias in Patients With Implantable Cardioverter- Defibrillators.”
Lampert, Rachel, Shusterman, Vladimir, Burg, Matthew, McPherson, Craig, Batsford, William, Goldberg, Anna, Soufer, Robert.
J Am Coll Cardiol 2009; 53:774-778.
Sources: Journal abstract, American College of Cardiology press statement, NHLBI.
Written by: Catharine Paddock, PhD