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Neurocardiology And The Spiritual Heart
Mohammed S. Uddin
The heart and its role on health was in the midst of confusion for centuries, until
William Harvey (1578-1657) in seventeenth century clearly defined its role.
However, in the medieval period, the Holy Book Qur'an defined the spiritual
aspect of the heart (Qalb), and the Traditions of the Holy Prophet (may Allah's
blessings and peace be on him) high lighted the anatomical and functional
aspects of the heart in early seventh century. This knowledge, however,
remained unknown, and continued to be ignored by the scientific community.
This article briefly reviews the history of ancient philosophical concept of
circulalatory system and compares it to the modern day scientific knowledge. It
addresses the role of brain (cerebral cortex or cranial brain) on the heart and
identifies the existence of cardiac intrisic neurological system that impacts the
cranial brain. Finally it attempts to identify the spiritual qualities of human heart
and its impact on human behavior.
Background:
The discovery of cardiovascular system occupies a very significant part of
medical history. In Europian Medicine, starting with Hippocrates (460-370 BC),
the history has recorded the difficulties of discovery tainted with
misunderstanding and wrongful applications. For almost 1300 years the
Europian medicine was in the grip of the theory of second century philosopher
and physician Caudius Galen (born 129 CE) until seventeenth century. The first
clear definition of circulatory system was established by William Harvey, in his
book De Motu Cordis in1628.
While Europe remained an ardent adherent of Galen's teaching, there was a
revolutionay light of Divine Knowledge in seventh century that kindled the heart
of Muhammad (may Allah's blessings and peace be on him) and the believers
through the revelation of the Holy Qur'an.
In the Holy Qur'an, word 'Qalb' (refering to the heart) is mentioned 132 times, and
its synonym 'Fuad/Af'ida' is mentioned few other times. It also mentions the
location of "Qalb' in the chest [(Sadr), 22:46]. In these verses, the Holy Qur'an
focused primarily on the spiritual diseases of the heart (viz disbelief, hypocrasy,
and trachery), and emphasized that belief in Qur'an and its practice are the
remedies for those diseases:
"We send down (stage by stage) in the Qur'an that which is a healing and
a mercy to those who believe..."
[Al-Isra, 17: 82]
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He (may Allah's blessings and peace be on him) emphasized the importance of
prevention of diseases over treatment, in a Hadith titled "Five before five". He
said: Take "From life before death, from health before illness, from youth before
old age, from wealth before poverty, and from leisure before work".
Nevertheless, the blessed Prophet (may Allah's blessings and peace be on him)
treated people with simple herbal medicine (the source of modern scientific
medicine) and asked people to seek medical advice. In a well-known Hadith he
related the wellbeing of the body to that of the heart:
"Beware! In the body there is a piece of flesh, if it becomes sound and
healthy, the whole body becomes sound and healthy, but if it gets spoilt,
the whole body gets spoilt, and that is the heart (Qalb)."
[Agreed upon, Bukhari and Muslim]
After the demise of the Prophet (may Allah's blessings and peace be on him),
Islamic Medicine flourished for centuries in medieval period, because of the
invaluable contributions of physicians like Hunayn Ibn Ishaq, Al-Razi, and Ibn
Sina among others.
But, in relation to the circulatory system, it was Ibn Al-Lubudi (1210-1267 CE)
who made the amazing discovery that heart is the first organ to develop in the
body. This remarkable discovery was followed by research of Ibn Al-Nafis (1213-
1288 CE). He defined the general circulation, coronary circulation and pulmonary
circulation, and published his findings in his book Al-Shamil fi al-Tibb (The
Comprehensive Book on Medicine) in 1242 CE. But this valuable knowledge
remained ignored by the Europian body of physicians, until the time of William
Hervey in seventeenth century.
To give credence to Ibn Al-Lubudi, it is noteworthy that the modern embryological
research has located the precardiac cells in the cardiogenic area of the embryo
at the beginning of the third week of gestation when the embryo is only 1-1.5 mm
in length, and the heart begins to beat when the embryo is only 2-3.5 mm in
length and only 22 days old. Heart sound is audible usually by the fifth week.
[The Developing Human, Moore Persaud, page 70, 7th edition]
Heart, Lungs and their functions:
Heart and lungs are at the center of health and life. They are lodged and
protected in the chest, called 'Sadr' in Arabic. They work as one unit to sustain
life.
The lungs inhale oxygen and exhale carbon dioxide. Oxygen is necessary for
cellular respiration (cellular metabolism). In cellular respiration oxygen is utilized
to break nutrients to release water, carbon dioxide, and energy; energy is
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necessary for functions of the body. Carbon dioxide, thus released, enters blood
and is returned to the lungs and exhaled. Excess carbon dioxide is harmful for
cells.
The bellowing effect of the thoracic cage helps creating negative pressure inside
the chest and assists the venous blood to return to the right side of the heart.
Blood circulates through the lungs, picks up oxygen and returns to the left side of
the heart; heart ejects the oxygenated blood into aorta for circulation. It also
generates sufficient forward pressure so that the blood can reach the remotest
part of the body. Once the blood delivers the oxygen to the tissues, it receives
the carbon dioxide from the cells and brings it back to the lungs to be exhaled
into the air.
Besides working as a mechanical pump, heart has other non-mechanical
functions: It secretes atrial natriuretic hormone, atrial peptide, epinephrine,
norepinephrine and dopamine, necessary for maintaining internal homeostasis of
fluid and electrolyte balance. It also acts like a peripheral brain sending impulses
to the cranial brain to keep it abreast of the physical and spiritual condition of the
heart. It also secretes Oxytocin, the birth and breastfeeding.
In addition, it generates an electromagnetic field around the body for cognition.
Structure of the Heart:
The heart has four chambers: two atriums and two ventricles; the right side
rceives the venous blood from tissues and the left side receives the oxygenated
blood from the lungs. Heart works as a mechanical pump: with contraction it
empties the blood and with relaxation it fills. Heart muscle is electrically
stimulated to contract, while relaxation is a passive process. This process of
phasic contraction and relaxation earned the heart its Arabic synonym of 'Qalb',
one that returns in cycles.
Heart has its own impulse generating and conducting system consisting of SA
node, AV node and Purkinze fibres. SA node (Sino-atrial node) is located high up
in the right atrium, AV node (Atrio-ventricular node) in the lower part of the right
atrium and the purkinjee fibres in the interventricular septum, arborising into the
cardiac muscle.
The conducting system is composed of specialized muscle cells, which are
capable of generationg electrical impulse at different rates; SA node being the
fastest (generally 72 times/minute, in adults). Being faster in rate, it sets the the
pace of rhythmicity for the rest of the heart.
The impulse generated by SA node travels to the last of the cardiac muscle cell
in 0.40 seconds and depolarize the entire heart leading to contraction. It
corresponds to systole. Repolarization is a passive process that corresponds to
diastole. This electrical impulse spread outside the heart into the rest body and
in its surrounding. An electrocardogram detects the intensity of the electrial
impulse and its direction of spread.
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Regulation of the heart:
The efferent pathways (brain to heart) start with Nucleus of Tractus Solitaries
(NTS) in the medulla oblongata. NTS besides being semi-autonomous, receives
impulses from cerebral cortex and subcortical center like thalamus,
hypothalamus and amygdala. Impulse from the NTS travels in the vagus nerve
and sympathetic chain to the heart and integrates with the intrinsic cardiac
neuron to stimulate the sinus node (the pace maker) that generates the electrical
impulse to stimulate the heart muscle.
The afferent pathways from the heart start in cardiac ganglia, travel up the
vagus nerve and sympathetic chain (via thoracic sympathetic ganglia and spinal
cord) and reach the NTS in the medulla oblongata.
Some fibers from the heart ascend directly, and indirectly (through NTS), to the
subcortical center like thalamus, hypothalamus and Amygdala, and finally to the
cerebral cortex to convey pain and body perception, sensation of huger, appetite
and emotions, which can affect the heart rate:
In addition, visual and auditory impulses (for fear, anxiety, fight/flight) directly
reach thalamus via the geniculate bodies, bypassing the lower cortical
processing in NTS. These secondary impulses from thalamus then descend
downward to the NTS (shorter route) for immediate action as in "Fight or Flight",
and ascend upward to the cortex for decisive action.
Several hormones released from the heart, which together with baroreceptor
impulses from the aortic and carotid sinuses, stimulate the NTS to regulate blood
pressure.
Afferent pathways by which
information from the heart and
cardiovascular system
modulate brain activity. Note
the direct connections from the
NTS to the amygdala,
hypothalamus and thalamus.
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The Dual Control of The Heart and Integration of
Response:
The vital function of the heart is guaranteed by a
unique set of two complementary nervous systems:
the cranial brain (through autonomic nervous
system) and the intrinsic cardiac neuronal circuit.
Heart's intrinsic network is enriched with complex
ganglia, neurotransmitter, protein and support cells,
same as those in the brain (John and Beatrice
Lacey).
When the central control fails, the local control will prevail and the heart will
continue to function. This is seen in state of deep sleep and central
unconsciousness.
The descending signals from the brain are integrated into the heart's intrinsic
nervous system along with signals arising from the sensory neurons in the heart
which are stimulated by intramural pressure, heart rate, rhythm and local
hormones. The final outcome is the integrated response between the descending
signals and the response of the intrinsic system to the above stimuli. Once
information has been processed by the heart's intrinsic nervous system, the
appropriate signals are sent to the sinoatrial node to generate impulse for heart
beat.
The Reverse Communication: Contrary to general understanding, the recent
findings show that the majority of the fibres in the vagus nerves are afferent
(ascending) in nature, and more of these afferent fibres are related to heart,
compared to other organs supplied by these nerves. Thus the message from the
heart travels to the brain via ascending pathways in both the spinal column and
vagus nerves, to different levels at medulla, hypothelamus, thalamus, amygdala,
and then to the cerebral cortex.
Heart and its Audio-Visual-Tactile Capability:
From a neuroscientific point of view, the heart works like a brain, having all the
capabilities to receive information, process, store and/or deliver. The intrinsic
system, in addition to regulatory function, receives audio-visual and tactile
impulses via thalamus and NTS to keep the heart in touch with the environment
we live in. Indeed it is part and parcel of our state of consciousness:
" And He gave you (the faculties of) hearing and sight and feeling (and
understanding)…" [As-Sajda, 32: 9]
Once impulses are received, the heart instantly interpretes them and directs
cranial brain to express its emotional response for emergency, as in fight or flight
Courtesy of Dr. J. Andrew Armour
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response, emotional tears, or happy face. Cardiac ganglia are capable of storing
short term memory, which then is transferred to the hypocampus for storage and
to frontal cortex for planning.
Juxtaposition of the Physical Heart and the Spiritual Heart (Qalb):
The Holy Prophet (saw), in the following Hadith, referred to the heart and its role
on health:
"Beware! In the body there is a piece of flesh, if it becomes sound and
healthy, the whole body becomes sound and healthy, but if it gets spoilt,
the whole body gets spoilt, and that is the heart (Qalb)." [Agreed upon,
Bukhari and Muslim]
In literal sense the Hadith applies to the physical heart and its effect on the
physical body: when the heart is healthy, the body is healthy, and when it is sick,
the entire body suffers.
An important aspect of this Hadith is that it specifically mention the word "flesh".
Flesh is inclusive of cardiac muscle, and conductive system of the heart which is
comprized of specialized muscle cells, and not of nerve fibres.
The Hadith may apply to the heart muscle in general like when the muscles are
weak, heart failure ensues and the body is sick, but more importantly any
irregularity in the conducting system can cause alteration in the rhythmicity of the
heart and severely jeopardize the physical health.
This Hadith was narrated fourteen century ago, when the knowledge about the
heart was more about its spiritual nature rather than about its structure and
function. But the use of the word 'flesh' in the Hadith shows that it was predicting
the future in the area of the scientific knowledge about this special organ.
In another version of the Hadith, it refers to the 'purity of the flesh':
"In the body is a piece of flesh that, if it is pure, the entire body is pure;
and if it is corrupted, the entire body is corrupted. Most surely, it is the
Qalb (heart)." [Bukhari and Muslim]
From medical point of view, there is no visible or chemical impurity about the
physical heart. However beside the general meaning, the state of purity could
apply to the state of spiritual health of the heart. Then the implication will be, if
the spiritual heart is spoilt by impurities like hypocrisy, it will affect the mind and
the actions of the body.
The Spiritual Heart:
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In the Holy Qur'an, the effects of different kind sins on the heart are expressed
through use of the words 'sealing' (Khatama), 'covering' (Akinnah), 'locking'
(Aqfal), 'rusting' (Ran), of the heart, but on visual inspection, there is no such
physical effect visible on the heart. These invisible 'entities' indicate their
metaphysical existence. Therefore, their application to the heart indicates the
existence of a non-physical dimension of the heart, which is reffered to as the
Qalb (Spiritual heart) in the Holy Qur'an.
Spiritual Heart is a sensory organ:
The Spiritual heart (Qalb) is receptacle for Divine Inspiration, Guidance and Glad
Tidings:
"Say: Whoever is an enemy to Gabriel-for he brings down the (revelation)
to thy heart by Allah's will, a confirmation of what went before, and
guidance and glad tidings for those who believe."
[Al-Baqarah, 2: 97]
"No kind of calamity can occur, except by the leave of Allah: and if any
one believes in Allah, (Allah) guides his heart (aright): for Allah knows all
things." [At-Taghabun, 64: 11]
It is the site of Fear, Faith and Trust:
" For, Believers are those who, when Allah is mentioned, feel a tremor in
their hearts, and when they hear His signs rehearsed, find their faith
strengthened, and put (all) their trust in their Lord."
[Al-Anfal, 8: 2]
Heart receives Warning:
"Thus have We sent by inspiration to thee an Arabic Qur'an: that you may
warn the Mother of Cities and all around her - and warn (them) of the Day
of Assembly, of which there is no doubt: (when) some will be in the
Garden, and some in the Blazing Fire."
[Ash-Shura, 42: 7]
It is the site of Peace:
"Behold! He (Ibrahim) approached his Lord with a peaceful heart."
[As-Saffat, 37: 84]
"Those who believe, and whose hearts find satisfaction in the
remembrance of Allah: for without doubt in the remembrance of Allah do
hearts find satisfaction."
[Ar-Ra'ad, 13: 28]
Heart is the House of Faith:
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"The desert Arabs say, "We believe." Say: "You have no faith; but you
(only) say: 'We have submitted our wills to Allah': For Faith has not yet
entered your hearts…" [Al-Hujurat, 49: 14]
It receives Guidance:
"Oh Allah! The Controller of the Qulub, direct our Qulub to Your Din"
[Prophet's supplication, Muslim]
Heart's spiritual faculties can see, hear, and inteprete the message:
The environment we live in is the textbook of learning.
The spiritual heart (Qalb), located in the chest, has the ability to spiritualize the
visual impulse. If one fails to spiritualize the visual impulse coming from the
environment, then it is blindness, not of the physical eye, but blindness of the
spiritual eye. A good example comes from the definition of Ih'san in the following
Prophetic Tradition:
"Do they not travel through the land, so that their hearts (and minds) may
thus learn wisdom and their ears may thus learn to hear? Truly it is not
their eyes that are blind, but their hearts which are in their breasts."
[Al-Hajj, 22: 46]
The word Ihsan ( إحسان†), means "perfection" or "excellence".
That definition comes from the Hadith of Gabriel in which Muhammad
(may Allah's blessings and peace be on him) states, "[Ihsan is] to worship
God as though you see Him, and if you cannot see Him, then indeed He
sees you". (Al-Bukhari and Al-Muslim).
History is the witness of the past. It is for us to learn lesson from history and
guide ourselves away from the sins that the previous generations did. They
ignored repeated warning and faced the consequences of total destruction. The
same way we can hear about, and can see the consequences left by them, and if
we ignore these warning, Allah can put a covering on our eyes and seal our ears.
Therefore, we must open our spiritual faculties of hearing and seeing to avoid
similar punishments.
"To those who inherit the earth in succession to its (previous) possessors,
is it not a guiding (lesson) that, if We so willed, We could punish them
(too) for their sins, and seal up their hearts so that they could not hear?"
[Al-'Araaf, 7: 100]
Spiritual heart, the unique distinguishing feature:
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Human brain and the heart are the distinguishing features of the Khalifah of Allah
(subhanahu wa ta'ala). Hearing, seeing and feeling are basic functions of the
brain. Human being has been endowed with the ability of higher perceptions of
these sensory impulses and to create their spiritual counter parts. Therefore, as
a human being one must not only hear but also listen, not only see but also
observe, not only feel but also understand. Thus, it is the joint functions of the
brain and the heart to fathom the spiritual message in Allah's creations:
"Many are the Jinns and men we have made for Hell: They have hearts
wherewith they understand not, eyes wherewith they see not, and ears
wherewith they hear not. They are like cattle- nay more misguided: for
they are heedless (of warning)."
[Al-'Araaf, 7: 179]
Fuad:
It is a special attribute of Qalb. It is the house of Truth, unshakable Faith,
Strength and Confidence:
" The (Prophet's) heart in no way falsified that which he saw."
[An-Najm, 53: 11]
This verse refers to Al-Ma'raj of the Prophet (may Allah's blessings and peace be
on him). During this sojourn, he was shown many unknown things and events.
He paid full attention to what he saw and what he saw were all previously
unknown to him. And next morning he narrated exactly what he saw. His Fu'ad
could not lie about what he saw, but the Quraish in attendance accused him of
lying. This verse was revealed to testify to the truth
Those who repeatedly reject the warning, and ask for Signs only to reject them,
they loose the mercy of Allah for Guidance and finally their faculties become
impermeable to Divine Message:
"And We shall turn their Af'ida and their seeing faculties, as refused to
believe therein for the first time…"
[Al-An'am, 6: 110]
"Allah has set a seal on their hearts and on their hearing, and on their
eyes is a veil; great is the penalty they (incur)."
[Al-Baqarah, 2: 7]
The Holy Book Qur'an was revealed in stages, over a period of 23 years, to firmly
ground the Verses in Prophet's heart (Fuad), for him to avoid mistakes and to
have a clear understanding. This verse was revealed to answer the nonbelievers
who asked: "Why is not the Qur'an revealed to him all at once?":
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"Thus (it was sent down in parts), that We may strengthen your heart
(Fuad) thereby, and We have revealed it to you gradually..."
[Al-Furqan, 25: 32]
Sadr (pl. S'udur):
When translated into English, 'Sadr' means the chest; a space bound by thorasic
cage on sides, the diaphragm below, and an outlet guarded by clavicles above
and by the spinal column on the back. Its contents are the heart, the great blood
vessels, the lungs, esophagus, some lymph nodes and the thoracic ganglia.
Taking a careful look at its 'costruction' and the structures it surrounds, one
quickly comes to the realization of its importance: the boney cranium protects the
brain, the spinal column protects the spinal cord , and now the thoracic cage
protects the organs that are at the center of our life.
In addition, it is also the center of all secrets of human thoughts and intentions.
The chest or the breast of human being is like a 'cyber space' where information
are kept secret, and no human can reach that information without a pass code.
Allah (subhanahu wa ta'ala), the Creator of the heaven and the earth and
whatever inbetween, knows that space, knows human heart and their intention,
and has reminded us repeatedly in the Holy Qur'an of His knowledge about our
secrecy and plans. On the day of Judgment, Allah (subhanahu wa ta'ala) will
look to the heart to judge by intention:
"And whether you hide your word or publish it, He certainly has (full)
knowledge, of the secrets of (all) hearts."
[Al-Mulk, 67: 14]
Sadr is also the chamber of Guidance. Allah (subhanahu wa ta'ala) expands the
chest of those who sincerely want to comprhend the Religion of Islam and makes
it narrow and tight for those tend to deliberately reject His Din.
"And whomever Allah wills to guide, He opens his chest to Islam; and
whomever He wills to leave to their whims, He makes his chest closed and
constricted, as if he is climbing to the sky (to catch his breath)…"
[Al-An'am, 6: 125]
It is also the site of treachery, conspiracy and whispering of the evil ones:
Seeking protection of Allah: "From the evil of the whisperer who withdraws (from
his whispering after one remembers Allah)", who whispers in the breast of
mankind, of jinn and men."
[An-Nas, 114: 4-6]
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Summary:
A human being has a body and an inner self. The inner self is composite of Ruh,
Soul, Heart, Mind and Brain. Ruh (Spirit) comes directly from Allah (subhanahu
wa ta'ala) and confers spiritual qualities to human being. Soul (Nafs) is the
driving forece behind our daily life; it has both earthly qualities and spiritual
qualities. Soul is the one that responds to our needs and presents to the mind for
justification and action. It can be trained to be completely spiritual (Nafs-al-
Muth,ma,innah). Mind is the command center while brain is the vehicle of
execution.
Heart has physical and physiological functions, but Qalb has only spiritual
functions. It is created pure and it sets the standard of purity for the soul to
reflect on. From neuroscience point of view, heart is equipped with all the
elements, like that of the brain, to act as brain (the peripherat brain). The cranial
brain and the cardiac brain (cardiac intrinsic nervous system) complement each
other and work synchronously to serve the body. Contrary to common
understanding, in the areas of spirituality, the cardiac intrinsic system acts as the
the receptacle for Divine Inspiration and Guidance. Fuad is a special attribute of
Qalb and Sadr is the cybre space of secrecy, details of which is best known to
the Creator, Allah (subhanahu wa ta'ala). Men benefit from all these beautiful
non-physical gifts that work harmoniously to make our everyday life complete and
comfortable.
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