November 2007, Volume 29, No. 11
Discussion Papers

Understanding Traditional Chinese Medicine organs in the context of modern medicine - Part 2: Zang Heart*

Edwin C L Yu 余秋良

HK Pract 2007;29:427-436


This paper describes the organs of Traditional Chinese Medicine on a platform that they can be understood by workers in scientific medicine. The Zang Heart is discussed as the same anatomical organ but with added dimensions. Formalized by the Zangfu manifestation theory in Chinese medicine, it could be a heart-mind or a motive-perfusion view. This is similar to a reform by some cardiologists as neurocardiology in modern medicine. This view may be a significant direction with added clinical significance in diagnosis and therapy.


本文以現代醫學角度陳述中醫學中的臟腑—心臟。在此將以慣常了解的解剖學器官討論中醫心臟及其附加元素。按中醫學的臟象理論, 心臟包括心神互動功能整體灌注的概念。這個觀點也許和現代醫學中的神經心臟學有相似之處。它在未來的發展可能有助臨床上的診斷和治療。


In my first discussion paper on Zang organs (zOrgans), it was pointed out that Traditional Chinese Medicine (TCM) describes only 5 zOrgans, with their meaning different from the word organ of modern science. These zOrgans (zang 藏 as the ancient Chinese word) are the major collect-and-store organs of the body and other body parts would be related to them. As a first example, the meaning of the Zang Kidney was described by quoting what orthodox TCM referred to, as well as the way it can be understood in modern science.1 I also put it in my integral-mechanistic-functional platform which should help to gather useful meaning.

Each of the zOrgans shall be described in successive papers to expose the added strength with better TCM understanding. In this paper, the Zang Heart (zHeart) will be described. The zHeart, for many at first encounter, seems to be describing our common usage of the word heart. But as in all zOrgans it refers to something more. For a better understanding, the integral concept in TCM is better explained first.

For a clearer wording, Zangfu organs will be written with a prefix as zOrgan (i.e. [肝] zLiver, [心] zHeart, [脾] zSpleen, [肺] zLung, [腎] zKidney) and Xue Blood as xBlood [血] to denote they are the same word but with broader meaning.2

Integral concept

Simply said, the body behaves as one whole during its reaction to and adaptation in its environment. This integral concept is open to varying interpretation. Such integral understanding is lacking in mainstream and even holistic medicine. It has been attributed to its reductionistic descent.3 It is often said that the whole is greater than the sum of all its parts, and represented sometimes with synergy.4 This justified many to use clinically the wholistic approach. That is well said, but actually it usually means only an integrated therapy, with listing problems and integrating whatever TCM, ayervedic, naturopathic and WSM therapeutic resources to treat each problem. The word "integral" is different from "integrated". Integral means a whole without needs or gaps amongst the parts. Integrative therapists who treat problems may not visualize how the many parts are interrelating and interacting as the whole reacts and adapts in its environment. The idea of integral (not integrative) approach is to return the person a full integral self with full dynamics and energy as he reacts and adapts even with the stressful environment. When realized, its expanded diagnosis and therapy5 help treatment of illnesses thought not remediable in the past.

TCM started with its refined understanding of nature and climates, and projected that the body would be reacting with each climate type with corresponding types of reactions. Abnormal reactions and adaptations are viewed as the roots of illnesses. Different adaptive faculties in the body respond correspondingly and these could be used to understand body illnesses even for influences not related to climate. It is to return to this harmony with nature that treatment restores the body to its integral whole. The words and classification may be ancient terminology, but the use of dichotomies like inner/outer, hot/cold, and deplete/replete 表裡寒熱虛實 is one integral method to allow shorter path and easier control of therapies to return the body back to its origin, the unitary whole. With this understanding, the body can be seen in its integral perspective, which is at its best functional-structural but in due course more functional in emphasis. The later course is one reason why most feel TCM a functional medicine.

It was probably the same drive why TCM chose to expand on only 5 major zOrgans and 6 zViscera五臟六腑, even when ancient Chinese had a fair knowledge of anatomy, with good record of measurement of organs and parts. To skip the interesting history and theory behind, the use of these numbers was needed to put body parts and everything into an integral whole in unity with nature which is also described with the theory of numbers. Zangs then refers to six, not five, zOrgans:- zHeart, zLiver, zSpleen, zLung, zKidney, and zPericardium. zPericardium was later left out, being not the core and for a better fit with the application of the five-element theory, the manner in which the organs dynamically regulate each other: negatively regulating and positively regulating cyclically. All these, and other principles not discussed here for space, are integral methods.

Integral perfusion

The body is constituted integrally by 5 zOrgans interconnected by channels and vessels. Ancient Chinese people"s worldview on nature about the earth and universe was already well developed and established from much study. Ancient scholars had to express their observations and experience cumulated about adaptations of the body, and the best was to put them in that worldview by analogy. The circulation with the vessels, channels and pulses are viewed as analogous to rivers and waters of the earth. Analogous to lakes and seas, the body was seen as constituted with reservoirs, called sea of marrow, sea of blood, sea of Qi, sea of grains, etc 髓之海,血海,氣海,水谷之海.6 Of course, for the circulation, only blood compartment counts. To note, the sea of blood 血海 is not the major circulation nor zHeart, but rather the Chong channel originating from the uterus, and directed by the zLiver, justified by its large portal circulation and splanchnic bed. I shall leave this discussion to the paper on zLiver. In short, while western medicine see the circulatory system constituted of the major circulation and the heart, TCM watches over the whole.

The rhythmic circulation perfuses the whole body, irrigates and supports its various parts. For each part to function well would depend on this perfusion. The ancient viewed life matter actualizing from Qi to form 氣聚成形,7 reducible in modern terms as saying "for functions, evolve structures". Only with perfusion can each part develop and specialize in function.

The zHeart, Zang Heart

Ancient Chinese certainly knew the anatomical heart. In fact the word heart心in Chinese is a pictographic word. Understanding in TCM reads, the main physiological function and features of the zHeart are: (1) governing blood in vessels; (2) housing the master spirit; (3) opening through the tongue, associated with pulses in the body, manifesting externally in the face and complexion, as joy in the emotions, as sweat at night; (4) mutually internal-externally interconnecting with the small intestine, with Meridian connecting. [心] 的主要生理功能有二:一是主血脈,二是藏神。[心]開竅於舌; 在體合脈;其華在面;在志為喜;在夜為汗。手少陰心 經與小腸之間相互絡屬,故[心]與[小腸]相為表裹。8

In short, the zHeart is not referring to the heart only. It basically includes the function of the heart, vessels, and part of the nervous system. Let me again use the integral-mechanistic-functional platform to help better understanding.

On the ground that the ancient TCM scholars meant the word morphologically equivalent to the anatomical organ of the same name but with added breadth and dimension, I believe that the zHeart refers to the heart with its set of reflexive control apparatus of medulla and related higher brain including thalamus, limbic system and the contextual cortex. That one functional structure serves important functions including monitoring and controlling the perfusion function through heart and circulation.

These functions may be separately described under (1) Body perfusion, (1a) Relating to the zIntestine inside out, (2) The attached zPericardium, and (3) Functions for Mental Control (Figures 1-4).

1. Body perfusion

The body with variable motivity in terms of integral needs has to be perfused to fulfill its adaptation and actions for functional actualization. This is essentially governed by the heart, and the integral body is healthy with vitality when perfusion is good. The heart as the motive force for blood circulation has all along been definite. In TCM, the zHeart governs vessels [心] 主血脈 , with vessels housing blood 脈為血之府 . For perfusion, the heart pumps blood and drives the major circulation through arteries manifesting in pulses. Perfusion is the root of life and living. Thus the zHeart is called the powerhouse for life 生之本.

1a. Relating to the zIntestine inside out

The zHeart is connected inside-out with the zIntestine 小腸 , Meridian connecting. This pairing relationship has not been well understood by many in modern terms. Here placed in terms of integral perfusion, it can be more easily understood, for the amount of absorption from the small intestine directly influences the degree of body perfusion and its irrigation. In fact, TCM describes the zIntestine as having two functions9:- 1. from gastric decoct to concocted and be assimilated 主受盛和化物 , 2. separation of the clear from the turbid 泌別清濁 . The clear, which is the food essence of fluid, pulse and grain, is absorbed and redistributed by the zSpleen to the whole body. The residue or the turbid is disposed down the large intestine or to the bladder. As zIntestine dominantly governs fluid with capacity 小腸主液 , it is its absorption that counts. Nourishment coalition 營 (ying, buildup, battalion), its nutritious fluid in vessels, is assimilated and forms blood 營行脈中,化生為血 .

2. The zPericardium, attached

Surrounding the heart, the pericardium acts physically to protect the heart, the most vital organ. TCM goes further to say that it protects the zHeart from inflictions: when exogenous pathogenic factors attack the heart, the zPericardium always takes the first blunt.10 Note that the zPericardium is in fact the omitted 6th Zang.

3. Functions for mental control

TCM relates the zHeart to the highest faculty, housing the primal soul 心藏神 . Note that the phrase 精神 , vigour, at present taken as one meaning, would be viewed as two separate things in the ancient. Shen 神 , with no exact western translation, has been translated variously as soul, consciousness, spirit, mind, psyche, vigour, etc. Here, let it first be understood as Attentiveness Mastery or Integral Mastery related to the spirit manifesting in the level of attentiveness. It is a feeling of mastery of integral uprightness, or integrity, as if it has good control of the whole body. It governs mental activity and consciousness. This integral control is dependent on cellular vitality and brain perfusion. Spirits are high only if brain perfusion and integral total body perfusion is good.

In TCM, the zHeart as key organ governs all other zOrgans as the supreme governor 心者,五臟六腑之大主也 .11 The understanding that the heart controls the whole body was generally prevalent in the old days and with most religions. In the west, the mind, heart, and body described integral whole body functions. Losing heart, lion heart, soft hearted means respectively frustrated, brave, gentle, etc. Even at present, the mind is related to the rational part and the heart to the emotional part. Similarly in Chinese, heart feelings, heart"s desire, thoughtfulness, work pressurizing the heart, without heart 心情,心願,心思,操心,無心 are similarly phrased. Ancient TCM was referring zHeart in this context, as it governs moods, wills and emotive thoughts, and all perceptive understanding. It also says that the zHeart takes charge of the performing out. It reads more like the modern brain itself which governs the whole body externally in behaviour and internally by control and feedback. Later, TCM revised itself in conceptual framework and modern TCM tends to re-ascribe much function to the brain. Then the zHeart meant more on the perfusion and less of these activities. This has become the more orthodox meaning of zHeart for recent centuries.

Thus, in TCM, while the zBrain houses the primal spirit 元神 and the Light of intelligence 精明之府 , zHeart stores Shen or Attentiveness Mastery. From this, as from the zHeart, the Illuminating Spiritual Intelligence 神明 or pure consciousness arises and is responsible for the alteration of attentiveness 神之變 , transforming between emotive and motive modes. From this, the mastery becomes prudent with the Intelligence 神明出焉 , and one can think fast and respond readily with clarity of mind. All these are dependent on good perfusion and resourceful function. Result: cardiovascular peace and heart-mind mastery.

Integral circulation and perfusion control

Modern TCM and its researchers try to put the ascribed mental functions of the zHeart to the brain. Most studies on the essential meaning of zHeart had been on the circulatory part, investigating on cardiocirculatory, endocrinal, immunological, and autonomic functions.12 Retrospectively, TCM scholars followed ancient Neijing until the Ming Dynasty when Li Shizhen re-formalized the zBrain housing the primal spirit 腦為元神之府 . Thereafter, centuries of debate started on which one houses the Intelligence. Any modern worker would well be tempted to treat the brain function and heart function as separate. But be open.

Modern workers tend to be framed by former views. In Western medicine, the circulation and the heart had been developed with a mechanistic view. Scientific studies centered on the heart as a pump for circulation, and separately on the brain as a centre of knowledge, emotions, and sensorimotor processor. But historically, the heart and the mind were not truely separate in Western medicine until the early 20th century. This body mind split still produces irresolvable tensions among medical intellects and in clinical interpretation where diseases of psyche or soma seem too remotely separated. Similarly it confuses lay felt understanding of the "breakable" hearty heart, and the unbreakable pumping heart. Fairly well are such accepted since the heart pangs, pulse races in apprehension, love and other emotional behaviour. There are now cardiologists moving back from heart and mind to heart-mind.13 Much work has been done on emotional body reactions. The midbrain including the amygdala monitors heart rhythm patterns and other body responses to sense how the body is feeling. Emotional stimuli from the environment or from memory are presented to the amygdala or orbitofrontal cortex which are trigger sites for emotion. Emotional reactions are released through hypothalamus, the basal forebrain, and the nuclei in the brainstem tegmentum, with visceral response and associated heart changes. In reverse, reacting from threat, stress or kindness, visceral sensations reach the anterior insular cortex with the stimulating event represented, and then reach the anterior cingulated cortex for second-order mapping and reflective coding.

I believe that the zHeart governs a delicate subliminal reflexive system to condition freewheeling of the circulation, so that every body parts can be well perfused and irrigated even in motion or emotion, to prepare a body readily maneuverable by the brain for adaptation and actualization. So, apart from mobility, motivity as directed by motives is also important. And the brain senses and works out for the body itself for that environment. The balance to be motive or emotive depends on its emphasis and strategic position. In either mode, the heart and viscera have to autonomically and autonomously work out their own perfusion need for that integral move, and the brain senses and coordinates with them. The heart is that delicate organ which becomes the chief sensor up-brain for body state and the chief brain-down effecter such that the body can be congruent with the mind to meet living demands. In original Neijing, there are five mental faculties: primal spirit stored in zHeart, corporeal soul in zLung, ethereal soul in zLiver, ideas in zSpleen, and commitment in zKidney [心] 藏神,[肺] 藏魄,[肝] 藏魂,[脾] 藏意,[腎] 藏志 .14 So the zHeart did not mean all the mental functions of the brain. Therefore, this does not preclude mental consciousness and thinking activities still be considered as functions of the brain in TCM.

It just well be that the heart is just uniquely positioned as a powerful central mediating point interconnecting body and mind, motivity and emotion. Unhappy emotional events, threatening life situations and motivational plans referring to previous memory banks for a charted course are registered with automatic adaptive changes of heart and body arousal, enabling the body for emotional events or stress environment. On top, the heart provides the necessary motive power for supporting perfusion for activities as the body transforms between emotive or motive modes.

Without enough space here, let me further describe a bit about integral perfusion. Perfusion also governs heat with body changes, analogous to climate changes on the weather produced by sea current effects. To note, ice-cream chills the circulation deep in the heart 凍入心 , and in fearsome situations, the heart felt chilled 心寒 . The irrigation of all body parts can hardly be summarized here. Here, let the part on description of the major circulation be the theme discussion.

Disease and pathophysiology (Figures 1-4)

In modern medicine, heart diseases and diseases of the major circulation include their functional and lesional problems, the best known being coronary heart disease, congenital heart disease, hypertension, and arrhythmias, among others.

The TCM zHeart disorders, with its wider context, include heart diseases, cerebrovascular diseases, and a range of functional psyche and integral perfusion disorders as insomnia, cardiac neurosis, fright, and even delirium.

TCM pathophysiology is discussed according to Zangfu manifestation theory. Essentially, zHeart pathophysiology talks about alterations in zHeart yin-yang dynamics and zHeart over-burning with heat, zHeart being categorized in fire in the five-element theory.

Let me first reclassify zHeart disorders as motive, motor, and motional circulatory problems, and motive, motivational, and emotive psyche problems. The motive is the driving force, whether for circulation or for psyche. With presumed adequate blood, it needs good energy to drive. The motive propagatory energy of and from the heart is called Heart Qi 心氣 . Only if there is ample Heart Qi can the blood circulate well to nourish the whole body. Heart-Qi and Heart-Yang deficiencies are associated with circulatory motive power problem.15 The blood compartment subject to the heart to pump, i.e. mainly the major circulation, belongs to the Heart Blood 心血 . When the two are strong, and vessels through unblocked, there is vitality and vigour. Short of these, diseases occur, including blood stasis and blocks 心血瘀阻,血脈阻滯 , causing symptoms like palpitations, chest pressure or even angina.

If the Heart Qi or Blood is deficient, there will be pallor and lustreless facial complexion, palpitation, deranged, knotted, or regularly interrupted pulse. If Heart Qi is insufficient, the pulse will be weak or irregular and the facial complexion pale, even to blood stagnation with cyanosis and cold limbs. If Heart Blood is insufficient, its nourishing function decreases and the Heart Qi has no support to lend, causing symptoms of vertigo, lassitude, shortness of breath and sweating.

Congestive heart failure means problem in circulatory motive power, and Heart Qi is inadequate. Same with cardiogenic shock. With functional arrhythmia, Heart Qi and Heart Yin may be variably deficient. With the problem of the motor due to heart organ itself, whether organic arrhythmias or coronary heart disease, the main factors would be microcirculatory blocks related to intravascular phlegm, fire, or blood stasis. Fire may be preliminarily understood as inflammation from waste metabolites not cleared by perfusion.

If the heart fulfills its physiological functions normally, with Heart Qi and Blood sufficient, there is clarity of mind. If Heart Blood is insufficient, it will lead to heart-mind unrest with palpitation, insomnia, dream disturbing sleep, poor memory, restlessness, etc. Worse, there may be loss of mental functions with hypersomnia, coma, or mental disorders with feeble-mindedness, delirium, manic agitation, etc.

Emotive problems often come when lacking the sustaining substance and irrigation, Yin. With inadequate irrigation and integral perfusion, the power of attentive mastery suffers with consequent worries and palpitations. Heart-Yin deficiency is associated with neurocardiovacular balance problems like insomnia, cardiac neurosis, and temperamental changes.

Such disturbances are of relevance to the many neurological problems even madness, stupor or Meniere"s disease. In modern TCM therapy texts, the heart, cardiovascular and cerebrovascular diseases are put in one chapter. Stroke and hemiplegia are included. To note, cerebrovascular accidents due to haemorrhage or thrombosis are related to a long list of causal factors (Wind, Fire, Phlegm, and Stasis) in the presence of zLiver and zKidney disturbances.

Heart Yin deficiency often facilitates exuberance of Heart Fire. The clinical manifestations of the zPericardium affected by external afflictions are the same as those of the zHeart. High fever, coma and red tongue are described as "heat attacking the Pericardium". Mental confusion, unconsciousness or mental disorder, are related to "phlegm obstructing the Heart Orifice". The fire states may be understood as inflammation, not resolved by reactive over exhausting perfusion during rescue for obstructions or when Yin inadequate.

These are the TCM syndromes, complex as the Heart Blood and Yin-Yang also rely on other zOrgans. For interest"s sake, the three most important TCM differential diagnostic tools, namely face, tongue and pulse, all belong to functional features of zHeart.

Confronting with modern medicine

Heart Qi as the motive force has been best understood. That the heart can maintain the blood circulation depends upon the function of the Heart Qi.

Does understanding zHeart help treating heart diseases? Cumulated meticulous researches in Western medicine have been notably powerful to tackle the circulatory mechanical balance. However, understanding integral perfusion by differentiating the major circulation, the expansible irrigative circulation and the microcirculation, has so far not been well defined, though important. Treatment for zHeart with TCM, in its own domain, mainly treats the delicate balance of the monitor and control of circulation. It also has additional benefits in diseases like coronary heart disease and arrhythmias.

It does help mediating the balance of body and mind, and emotion vs. mental function. There are not as many strong zHeart herbs as those like zKidney herbs, but there are various good herbal combinations treating zHeart, with much help for mental unrest. Note that without medicine, even positive feelings, being virtuosity promoting, help in heart rhythm. Studies have shown that heart centered psychophysiological coherence techniques facilitate the body"s healing processes and improve physical health outcomes in hypertension, diabetes, and congestive heart failure.16 TCM drive towards integral treatment emphasizes the balance of the circulation and perfusion. Cardiac neurosis or cardiac syndrome X can be treated with good results. Subject to perceived body arousal by the way of feelings, the motivational needs of the body determine its behaviour. While thinking and feeling are both important, thinking is clearer when emotional state is balanced, emotive aligned with motive, with more stable autonomic body states. Result: vitalizing with vigour.

Concluding remarks

"One machinery, one set piece" may be a good motto. After all, is it better to view the system as the controlled set or just the mechanistic part? Ancient TCM started with primary understanding to relieve pains and illnesses through treating the mind and body as one. Now, half-heartedly, understanding of integral perfusion from major circulation alone may not be the only way.

The clear understanding of the heart brain unit, the body central core, will help. The above description is a simplistic view. More understanding of the zHeart and its management would restore the understanding of the heart as the sensor and effecter to freewheeling integral perfusion. Treatment on heart may now expand in treating the circulation as what is standard in Western medicine, and in the additional TCM methods. Mainstream medicine may consider resetting its perspective with this heart-mind or motive-perfusion view.

Key messages

  1. The word heart in old days means the pumping heart as well as the perceptive emotive heart.
  2. Zang Heart functions include governing blood in vessels, as circulation associated with pulses, manifesting in the face and tongue.
  3. Zang Heart is the powerhouse for life and living. It houses the spirit with Integral Mastery allowing transformation between life functions: motive and emotive modes.
  4. Understanding the Integral Concept as how the whole body reacts and adapts in its environment helps understanding its need for reflexive monitoring and control of good perfusion even in motion or emotion to prepare a body-mind ready for adaptation and actualization.
  5. The heart is uniquely positioned as a powerful central mediating sensor and effecter, interconnecting body and mind, motivity and emotion.
  6. Modern understanding should link the thalamus and limbic system and their associated contextual cortex in a cardio-neurological axis with the medulla-driven cardio-circulatory system as essential function of zHeart. This one anatomico-functional structure as a heart-brain unit mediates integral perfusion at psychophysiological balance of motive and emotive functions.
  7. Main symptoms of zHeart dysfunction include cardiovascular unrest and loss of heart-mind mastery with palpitations, arrhythmia, fright, insomnia, restlessness and even delirium in ill health, heart diseases, and cerebrovascular diseases.

Edwin C L Yu, MRCP (UK), FRCP (Glasg), FHKAM, RegCM
PHonorary Professor,
School of Chinese Medicine, Hong Kong Baptist University.

Correspondence to : Dr Edwin C L Yu, c/o INTEMED H.K., Room 1902-03, Chung Kiu Commercial Building, 47-51 Shantung Street, Mongkok, Kowloon, Hong Kong.

  1. Yu E C L. Understanding Traditional Chinese Medicine Organs in the context of modern medicine- Part 1 Zang Kidney. HK Pract 2007;29:311-320.
  2. Yu C L. The essence of terminology, the way to describe the body and its diseases, World Integrated Medicine Congress, Abstracts, Beijing 1997:89.
  3. Lawrence C, Weizz G, ed., Greater than the parts, Holism in Biomedicine 1920-1950, Oxford University Press, 1998:2.
  4. Synergy, Wikipedia, the free encyclopedia,
  5. Yu E C L. Integral Therapy, Symposium on Conferment of School of Chinese Medicine Honorary Professorship, Hong Kong Baptist University, June 2004: 12.
  6. 王冰校正,唐:黃帝內經
  7. 鄭玄注,漢:易緯
  8. Basic Theories in Chinese Medicine 中醫基礎理論, Ordinary Higher Education Chinese Medicine Category, Standard Education Material, Shanghai Scientific Technology Press, 1994: 70.
  9. Basic Theories in Chinese Medicine 中醫基礎理論, Ordinary Higher Education Chinese Medicine Category, Standard Education Material, Shanghai Scientific Technology Press, 1994: 74.
  10. 王冰校正,唐:黃帝內經
  11. 王冰校正,唐:黃帝內經
  12. Zhang WK, ed. Integrated Traditional Chinese Western Medicine 中西醫結合醫學,chapter 3, section 1 心的研究 2000:219-234.
  13. Armour J, Ardell L, ed., Basic and Clinical Neurocardiology, Oxford University Press, 2004.
  14. 王冰校正,唐:黃帝內經
  15. Zhou ying, et al, Cardiovascular performance by observing left ventricular function in Heart Qi deficient patients, CJIM 1995;15:13.
  16. Luskin F, Reitz M, Newell K. Pilot study of a group stress management training on elderly patients with congestive heart failures. J Cardiopulm Rehabil 2000; 20: 303.