Brain and Heart: Vital but different

By Dr Upul Wijayawardhana-December 17, 2017, 9:20 pm 

There is no doubt that the brain and the heart are the two most vital organs in the body, as they not only dictate your life but also cause death when they stop functioning. Not that other organs do not play an important role but their malfunction does not produce the same dramatic effect. Though as a Cardiologist by training, I should support the supremacy of the heart, I have often wondered whether the heart has been revered with many attributes without much justification. For instance, artistes, whether they be writers, poets, singers or painters, attribute emotions to the heart. They say we love with our heart, but do we? Is it not the mind that generate emotions? Where does mind reside? In the brain, in the heart, both or nowhere? Gautama Buddha, very aptly, described the mind as ‘Faring far, wandering alone, bodiless, lying in a cave’ (Duran gaman,EkaCharan,Asariram,guhasiyam) But which cave?

Many songs come to my mind but, for the reason that may become obvious later, I have chosen Narada Dissasekara’s beautiful song:

"Muluhadin mama eyata pemkota, anagatha pem sihina mawwemi.

age sonduriya wenath kenekuta, aithiwunu heti bala dukwemi"

Translated, rather crudely, as:

"Having loved her with all my heart, created future romantic dreams. My love was snatched by another, seeing how it happened, I weep"

Change of just one word could have made the difference; instead of hadin (heart), hithin (mind)could have been substituted, without change in rhyme or rhythm, but making it more accurate, scientifically. After all, love is in the mind!Or is it? Whatever scientists say, from time immemorial, emotions have always been associated with the heart but not all. You do not get depressed with the heart but when you get depressed, you can be heart broken.

In fact, research has given new meaning to the concept of a broken heart and, indeed, you can die of a broken heart. Japanese researchers reported, in 2001, a syndrome where there was acute dilatation of the left ventricle (the main pumping chamber of the heart). As the heart, on injecting dye and taking angiograms, showed an appearance similar to that of an octopus trap, they called it "Takotsubo cardiomyopathy". On further investigation, they found it to be due to acute stress like the death of a loved one, break-up of a relationship etc. Patients present either like a heart attack or in heart failure but, on investigation, coronary arteries (the arteries that supply blood to the heart muscle) are normal with no narrowing or clots.Most recover but a tiny minority may die due to worsening heart failure or, even more rarely, due to rupture of the heart. Thus, there is truth to the old saying ‘died of a ruptured heart’ (Hadawath pelila meruna).

How does this happen? It happens simply because the heart is full of nerve fibres, being second only to the brain. Heart is mechanically a pump, but for it to beat appropriately, faster when needed and vice versa, regulatory nerve impulses are needed. There are two types of impulses in the autonomic (the one we do not perceive) nervous system: sympathetic, to accelerate the heart when we have to run or get excited and parasympathetic, slow down the heart when resting or asleep. It is the torrential flow of sympathetic impulses that can cause a ‘broken heart’, virtually paralysing the main pumping chamber.

Interestingly, the heart is rich not only in nerve fibres but also in nerve cells; a fact discovered due to observations made after heart transplants. As mentioned in my article "Mending the heart" (The Island, 9th December), it is 50 years since the first successful human-to-human heart transplant. One of the most interesting observations following heart transplantation is change of personality, though it happens only rarely. One of the best documented cases is that of a lady who, after transplant, started liking beer she hated previously and wanting to ride motorcycles which she was scared of previously. It transpired that she had received the heart of a keen motorcyclist, fond of beer, who died following an accident. Some postulate that there may a tiny brain in the heart! Not a real brain but a collection of nerve cells, seen nowhere else.

Why has the brain played second fiddle?

One of the reasons may be that it is not a dramatic structure. Even in the living, it is a semi-solid lump not showing any features of life, unlike the heart which beats vigorously. Just last week, an amazing case was reported from Glenfield Hospital in Leicester, the centre to which I referred most of my patients for cardiac surgery when I was in active practice. This was a child born with the heart beating outside the body due to the absence of the breastbone. The pictures shown on television news was very dramatic and no picture of the brain can match this. Surgeons, having detected this abnormality prior to birth by ultrasound examinations, were ready to cover the heart up, soon after delivery. Child will need an artificial breastbone and, obviously, will need more operations but would be able to live a normal life, ultimately.

Our brain works like a computer, doing many complex tasks by exchange of tiny electrical impulses and building of microscopic connections, millions of them every minute.

One of the cardinal differences between the heart and the brain is in the modes of treatment. Though heart transplants have been done for over half-a-century and artificial hearts are within sight, this form of therapy is impossible with the brain. Brain transplants or artificial brains are not within the realm of possibility. The only options are preventing brain damage and helping repair; stem cell therapy playing a vital part.

New drugs for degenerative diseases of the nervous system

News came, last week, of what could be the most important breakthrough in the last fifty years, for the management of degenerative diseases of the nervous system. It was in the treatment of Huntingdon’s disease, a hereditary condition that leads to abnormal movements, dementia and paralysis leading to a slow painful death in relatively young people. Scientists at University College, London reported that they had success with a new form of treatment. Huntington’s is caused by an error in a section of DNA called the huntingtin gene. Normally this produces a protein called huntingtin which helps in brain development but an error leads to the production of a toxic variety of huntingtin which damages brain cells. The treatment is to silence the gene by infusing into the fluid surrounding the brain and spinal cord a drug that attacks the messenger protein, RNA. Infusions had been given to 46 patients with resultant decrease of the toxic variety of huntingtin. The drug was well tolerated and safe but this is just the beginning of a long process that gives a glimmer of hope to a condition which was untreatable, so far. If this is successful, similar medications for diseases like Parkinson’s and dementia are very likely to be developed.

Artificial hearts

In my previous article I briefly mentioned about artificial hearts. Initially, scientists tried to imitate the heart with pumps that beat, squeezing the blood just like the heart did but there were many problems including clotting of blood in these pumps. A device developed for children, where a rotatory device was used to squeeze blood running through a tube with high frequency rotation has been shown to be effective in adults as well and research is now concentrated on this type of device. But, it may all change due to the advent of 3D printing. Using this technique, scientists in Zurich had created the world’s first soft artificial beating heart which looks very much like a normal heart and is well worth watching:http://miami.cbslocal.com/2017/12/07/artificial-organs-health-research/

However, there is one problem; this heart can beat only 3000 times, just over 30 minutes, as the material cannot stand the strain. Now the search for durable materials start and whether one can be found, we do not know. Hope there is success.

Stem cell therapy

This is the most promising of all treatments, not only for diseases of heart and brain but many other organs. Cell therapy for chronic ischaemic heart disease and heart failure is already available on experimental basis at research centres. Stem cells harvested from a recipient is infused through coronary arteries or injected direct to the heart muscle with good results. Stem cells have the innate ability to develop into any type of cell and the expectation is that the infused stem cells will grow into heart muscle cells with recovery of function. If successful, this can be applied to diseases of many other organs. Again, this is just the beginning of a long journey but, overall, the most promising one that may revolutionise the practice of medicine.

(The writer is a cardiologist)