Some more indication that anger and negative feelings have adverse effects on heart health. Researchers from Yale University followed 62 patients who were equipped with implantable cardioverter-defibrillators (ICDs). These patients were suffering from coronary artery disease or dilated cardiomyopathy that made them to wear ICDs. An ICD is a battery-operated implantable device that detects abnormal heart rhythms (arrhythmias). Once arrhythmia is detected, it applies a corresponding electrical jolt to restore the rhythm back to normal.
According to Arrhythmia Alliance, a UK-based charity organization, most modern ICDs function in 3 ways:
If your heart beats too fast, the ICD can give you a burst of extra beats at an even faster rate which will normally return your heart back to a normal rhythm. This is called anti-tachycardia pacing (or ATP)
If the anti-tachycardia pacing doesn’t bring your heart back to a normal rhythm, or if the ICD senses a faster rhythm called ventricular fibrillation, the ICD can then give a higher energy shock. This is called defibrillation
The patients in the current study were asked to undergo a mental stress test by recalling a recent situation or incident wherein they were angry or aggravated. The T-wave alternans (TWA) of the patients were measured during the recollection. TWA is a measure of the electrical stability of the heart. Long term follow up consisted of monitoring for a mean of 37 months which patients had arrhythmias that required termination by the ICD.
According to Dr. Rachel Lampert, associate professor at Yale University School of Medicine “It’s an important study 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. In this study, we found patients with higher levels of anger-induced TWA were more likely to experience arrhythmias requiring ICD termination.”
It seems that patients with higher TWA induced by anger and strong negative emotions were predisposed to arrhythmias. Arrhythmias are irregularities in heart rhythms that can lead to sudden cardiac death.
In current study, 16% of patients with ICD-terminated arrhythmias during the follow up period had higher TWA induced by anger compared with those patients who did not have arrhythmias. Anger-induced TWA was a significant predictor of arrhythmias that led to a ten-fold increased risk compared to patients with normal TWA.
How TWA relates to heart rhythm irregularities is not so clear. Unlike physical exercise, mental stress due to anger does not increase heart rate. This suggests that TWA changes associated with mental stress “may be due to a direct effect of adrenaline on the heart cells.”
A previous post touched on the effect of negative emotions on heart health. Anger and hostility were associated with a 19% increase in coronary heart disease (CHD) events in healthy individuals and a 24% increase in risk among those with pre-existing CHD.
Truly, there is a need to consider anger management and other behavioural interventions an essential part of heart disease prevention and management.
Coming next: tips on anger management.