Dr's Casebook: Valentine’s Day and the heart’s own little brain

So, if your pulse quickens when you open that Valentine’s card it may be the little brain in your heart that is reacting. Photo: StockAdobe

Valentine’s Day is traditionally associated with the heart. For centuries poets, writers and lovers have been convinced that the seat of our emotions reside in the heart. It is no surprising really, since when we get emotional or feel stressed, the heart can react to show it.

Dr Keith Souter writes: The scientific view, however, has been that the heart is merely a pump and that the quickening of the pulse when we feel stressed, attracted or fall in love is just the result of different hormones affecting the pump.

Well a whole new field of medical science called neurocardiology is questioning this.

Research is showing that the heart actually has its own nervous system, effectively it has its own brain.

Now scientists from the Karolinska Institute in Sweden and Columbia University in the USA have been doing research on the hearts of zebrafish and have shown that the heart has its very own nervous system within the muscles and this controls the heartbeat.

This is fascinating research with the potential to develop new treatments for heart disease.

The zebrafish heart has striking similarities to the human heart in terms of structure and function.

The scientists have identified several types of nerve cells in the heart that have different functions. Using a variety of research techniques including single-cell RNA sequencing, anatomical studies and electrophysiological techniques, they have been able to map out the composition, organisation and function of the network of nerve cells within the heart.

This network seems to be separate from the brain and central nervous system and the sympathetic nervous system that is thought to have such a prominent role in stress and its effect on the heart.

It would seem to offer an explanation about how some emotional states can affect the heart, but for which our standard drugs do not work.

The ‘heart’s little brain’ hypothesis suggests that the heart actually has some ability within it to learn, remember, and make functional decisions on the way the heart functions, which is independent of the brain and central nervous system.

This has potential to help us to understand the interaction between brain and heart in conditions like anxiety, depression and Post traumatic stress disorder or PTSD.

So, if your pulse quickens when you open that Valentine’s card it may be the little brain in your heart that is reacting.