There is a brain in the heart!

Dr. Muhammad Sayed Inam 
The heart is not just a pump. It possesses its own neural network system which is known as the “Little brain” or “Heart brain”.
‘Little Brain’ or ‘Heart Brain’ is a network of neurons known as the intrinsic cardiac nervous system (ICNS). ICNS plays a key role in regulating cardiac activity.
The ‘Heart brain’ is composed of approximately 40,000 neurons that are identical to brain neurons, demonstrating that the heart has its own nervous system. The heart also communicates with the brain in a variety of ways, including neurologically, biochemically, biophysically, and energetically.
The vagus nerve, which is 80% afferent, carries information from the heart and other internal organs to the brain. Signals from the “heart brain” redirect to the medulla, hypothalamus, thalamus, amygdala and the cerebral cortex. Thus, the heart sends more signals to the brain than vice versa.
The heart is also considered the source of emotions, desire, and wisdom. Even it can encode, store and retrieve the memories.  The heart generates the largest electromagnetic field in the body. The electrical field as measured in an electrocardiogram (ECG) is about 60 times greater in amplitude than the brain waves recorded in an electroencephalogram (EEG).
Is it possible for the heart to remember?
What the mind forgets, the heart remembers. Cardiac memory, often known as the “Chatterjee phenomenon,” is a type of memory that occurs in the heart. (After a period of abnormal ventricular activation, such as ventricular pacing, intermittent left bundle branch block or pre-excitation, the heart ‘remembers’ and mirrors its repolarization in the direction of the previous QRS. It usually manifests as T-wave inversions that can linger up to weeks after the provocative event).
Heart transplant and personality changes:
Patients with heart transplants may undergo personality changes that mirror their donors’ experiences, likes, dislikes, and dispositions. There have been multiple reports of heart transplant recipients taking on the personality traits of their donors, according to studies.
( Dr. Muhammad Sayed Inam is an Assistant Professor of Psychiatry at Sylhet MAG Osmani Medical College)