It’s not surprising that any kind of trauma can produce a biochemical reaction. Being repeatedly exposed to something that causes your body to change in a different way is called pathophysiological stress.
In the case of a life-changing death of a child, the emotional shock and uncertainty about the right course of action are compounded by a physiological threat.
This may affect different parts of the heart differently depending on the age, sex and social or family background of the child and family. It may also change slightly with each subsequent loss of a child.
Research suggests these changes are likely to be seen within the right atrium, the right ventricle and possibly even the right artery.
This has been the subject of a recent study by Professor Fred Sears of the Centre for Stress and the Brain at the University of Sydney and colleagues. The results were published in Circulation on 9 February.
The researchers used skin samples to analyse gene activity (or SNPs) from around the left ventricle and the right chamber. They compared DNA sequencing of affected people with autopsy and brain biopsy samples from people without the condition.
The data included DNA sequences and gene activity associated with known heart failure and other cardiovascular diseases.
There was an increased level of DNA recognition in healthy heart failure patients (excluding those who died before diagnosis) when they were exposed to stressors such as traumatic emotional circumstances, bereavement, bereavement in the children of survivors, panic disorder, seizures and physical aggression, as well as when they were exposed to death of a child or parent.
This work adds to a growing body of research showing that physical changes in the heart accompany medical distress.
A reversal of heart structure
One of the most interesting observations from the study was that heart structure and function also tended to reverse following a stressor that resulted in a death of a child. This appeared to be at the reverse end of the spectrum from that in the adults.
This may reflect changes in sensitivity of heart tissue to physical stress associated with sudden death. However, a mechanism for reversing heart structure following bereavement is not yet clear.
There have been a number of genetic variations previously associated with increased risk of heart failure in survivors of trauma who were widowed or divorced. It is likely these genetic variations may be present in those who survive bereavement and may also explain the observed reverse response to loss of a child.
The flip side of reverse effects
The reverse effects of certain stressors, such as bereavement and physical threat, may be contrary to recent theories that stress and chronic stress have the same effect on the heart.
One of the most important up-coming research areas is understanding the effects of chronic stress and exposure to violence on the heart. The high-profile rise in cardiovascular deaths from severe stress, such as that experienced by the British Steel worker, has brought more attention to the issue.
We know that the scarring of human tissues during labour and birth, stress during neonatal development, and chronic exposure to violence, often go hand in hand. Research has increasingly shown this.
Recent studies have shown that extreme assaults during childhood can activate the hearts of ageing adults, particularly in the case of children (e.g. animals in live comparison.)
However, the explanation for this extreme response is not yet understood. The information gained from this study will be useful in guiding future research strategies.