《伤寒明理论》释悸字云∶悸、心忪也。筑筑惕惕然动，怔怔忪忪不能自安也。则悸即怔忡，而
今人分为两条谬矣。心悸之由，不越二种，一者虚也，二者饮也。气虚者，由阳气内虚，心下空虚，
火气内动而为悸也。血虚者亦然。其停饮者，由水停心下，心为火而恶水，水既内停，心不自安，故
为悸也。有汗吐下后正气内虚而悸者，有邪气交击而悸者，有荣卫涸流脉结代者，则又甚焉。必生津
液益血以实其虚，此从伤寒而论者。若杂病则考诸《内经》云∶心痹者，脉不通，烦则心下鼓。胆病
者，口苦呕宿汁，心下澹澹，恐如人将捕之状。足阳明是动，闻木音则惕然而惊。心包络是动病，心
中澹澹大动。肾是动病，善恐，心惕然如人将捕之。《原病
式》云∶因水衰火旺，其心胸躁动，谓之怔忡，然后知悸之为病，是心脏之气不得其正动，而为火邪
者也。盖心为君火，包络为相火，火为阳，阳主动，君火之下阴精承之，相火之下水气承之。夫如是
而动，则得其正而清净光明，为生之气也。若乏所承，则君火过而不正，变为烦热，相火妄动，既热
且动，岂不见心悸之证哉。况心者神明居之。经曰∶两精相搏之谓神。又曰∶血气者，人之神。则是
阴阳气血在心脏未始相离也。今失其阴，偏倾于阳，阳亦以失所承而散乱，故精神怔怔忡忡不能自安
矣。如是者，当自心脏中补其不足之心血，以安其神气。不已则求其属以衰之，壮水之主以制阳光也。
又包络之火，非惟辅心，而且游行于五脏，故五脏之气妄动者，皆火也。是以各脏有疾，皆能与包络
之火合动而作悸。如是者，当自各脏补泻其火起之由，而后从包络调之平之，随其攸利而治。若各脏
移热于心，而致包络之火动者，治亦如之。若心气不足，肾水凌之，逆上而停心者，必折其逆气，泻
其水，补其阳。若左肾之真水不足，而右肾之火上逆，与包络合动者，必峻补左肾之阴以制之。若内
外诸邪郁其二火不得发越，隔绝荣卫，不得充养其正气者，则皆以治邪解郁为主。若痰饮停于中焦，
碍其经络不得舒通，而郁火与痰相击于心下以为怔忡者，必导去其痰，经脉行，则病自已。丹溪云∶
怔忡，大概属血虚与痰。有虑
便动者，属虚。时作时止者，痰因火动。瘦人多是血虚。肥人多是痰饮。真觉心跳者是血少，宜四物
安神之类。《金匮》云∶食少饮多，水停心下，甚者则悸，微者短气。又云∶心下悸者，半夏麻黄丸
主之。亦可用温胆汤，或导痰汤加炒酸枣仁、下寿星丸，及茯苓饮子、茯苓甘草汤、姜术汤、五苓散
之类，火盛加黄连。脉结代而悸，炙甘草汤。久思所爱，触事不意，虚耗真血，心血不足，遂成怔忡，
宜养荣汤。感风寒暑湿闭塞诸经而怔忡者，各见本门。或有阴火上冲，怔忡不已，甚者火炎于上，
或头晕眼花，或齿落头秃，或手指如许长大，或见异物，或腹中作声，此阴火为患也。治宜滋
阴抑火汤。心不宁者，加养心之剂。日久服降火药不愈，加附子从治，或入参 亦可。有失志者，由
所求不遂，或过误自咎，懊恨嗟叹不已，独语书空，若有所失，宜温胆汤去竹茹，加人参、柏子仁各
一钱，下定志丸，仍佐以酒调辰砂妙香散。有痞塞不饮食，心中常有所歉，爱处暗地，或倚门后，见
人则惊避，似失志状，此为卑 之病，以血不足故耳。宜人参养荣汤。脾胃不足者，谷神嘉禾散加当
归、黄 各半钱。
《伤寒明理论》对“悸”字的解释是：悸，就是心忪（心中惊恐不安）。心脏筑筑跳动、惕惕不安，怔怔忡忡不能自我安宁。那么悸就是怔忡，而现在的人将其分为两种病症是错误的。
心悸的成因，不外乎两种：一是虚证，二是饮邪。气虚导致的，是因为阳气内部虚弱，心下空虚，火气在内扰动而引发悸动。血虚导致的也是如此。停饮导致的，是因为水饮停聚在心下，心属火而厌恶水，水既已内停，心便不得安宁，所以产生悸动。有因发汗、催吐、泻下后正气内虚而致悸的，有因邪气交击而致悸的，有因营卫枯竭流行、脉象结代而致悸的，这就更严重了。必须生津液、益血液以充实其虚损，这是从伤寒角度论述的。
如果是杂病，则考察《内经》的说法：心痹病患者，脉道不通，烦闷时感觉心下鼓动。胆病患者，口苦呕吐宿汁，心下澹澹然动摇，恐惧得像有人要抓捕自己一样。足阳明经发生变动，听到木器敲击的声音就会惊惧。手厥阴心包络发生变动病证，心中澹澹然大动。足少阴肾发生变动病证，容易恐惧，心中惕惕然像有人要抓捕自己一样。
《原病式》说：因为水衰火旺，心胸躁动，称为怔忡，由此可知悸这种病，是心脏之气不能正常搏动，而被火邪所扰。大概心为君火，心包络为相火，火属于阳，阳主动，君火之下需要有阴精来承奉，相火之下需要有水气来承奉。像这样有承奉而动的，就符合正道，表现为清净光明，是生发的元气。如果缺乏承奉，君火过盛而不正，变为烦热；相火妄动，既热又动，这难道不是心悸的症状吗？
况且心是神明居住的地方。经文说：两精相搏叫做神。又说：血气是人体的神。那么阴阳气血在心脏中从未分离过。现在失去了阴，偏倾于阳，阳也因为失去承奉而散乱，所以精神怔怔忡忡不能自我安宁。像这种情况，应当从心脏中补益不足的心血，以安定神气。如果无效，则寻求其所属脏腑来抑制它，即壮水之主以制阳光。
另外，心包络之火，不仅辅助心，而且游行于五脏，所以五脏之气妄动的，都是火的作用。因此各脏有病，都能与心包络之火合动而引发悸。像这种情况，应当从各脏补泻引起火动的根源，然后从心包络调理平复，根据具体情况治疗。如果是各脏移热于心，导致心包络之火动，治疗也如同上述方法。
如果是心气不足，肾水凌犯，逆上而停聚于心，必须折抑其逆气，泻其水邪，补益其阳气。如果是左肾真水不足，右肾之火上逆，与心包络合动，必须峻补左肾之阴以制约它。如果是内外各种邪气郁滞，使二火不得发散，隔绝营卫，不能充养正气，都应以治邪解郁为主。
如果是痰饮停在中焦，阻碍经络不得舒通，郁火与痰相互搏击于心下导致怔忡，必须导去痰浊，经脉通畅，病自然痊愈。丹溪说：怔忡，大体属于血虚和痰。有忧虑就动的，属于虚证。时作时止的，是痰因火动。瘦人多属血虚。肥人多属痰饮。真正感觉心跳的是血少，适宜用四物汤安神之类的方剂。
《金匮要略》说：食少饮多，水停心下，严重的则悸，轻微的短气。又说：心下悸，用半夏麻黄丸主治。也可以用温胆汤，或导痰汤加炒酸枣仁、下寿星丸，以及茯苓饮子、茯苓甘草汤、姜术汤、五苓散之类，火盛加黄连。脉结代而悸，用炙甘草汤。
长期思念所爱之人，遇事不如意，虚耗真血，心血不足，遂成怔忡，宜用养荣汤。感受风寒暑湿闭塞诸经而致怔忡的，各自见本门章节。或者有阴火上冲，怔忡不已，严重的火炎于上，或者头晕眼花，或者牙齿脱落头发稀疏，或者手指如许长大，或者看见异物，或者腹中作声，这是阴火为患。治疗宜用滋阴抑火汤。心不宁的，加养心之剂。日久服用降火药不愈，加附子从治，或者加入人参也可以。
有失志者，由于所求不遂，或过错自责，懊恨嗟叹不已，独语书空，好像有所失，宜用温胆汤去竹茹，加人参、柏子仁各一钱，下定志丸，仍佐以酒调辰砂妙香散。有痞塞不饮食，心中常有所歉疚，喜爱处在暗地，或倚靠门后，见人则惊避，类似失志状态，这是卑慄的病，这是因为血不足所致。宜用人参养荣汤。脾胃不足的，用谷神嘉禾散加当归、黄芪各半钱。
The *Shanghan Mingli Lun* (Clarification of Principles in Cold Damage) explains the character "Ji" (Palpitation/Startle) as follows: Ji is synonymous with Xin Song (a sensation of fright and uneasiness in the heart). It manifests as a thumping and trembling movement, a state of constant apprehension and inability to feel at ease. Thus, Ji is equivalent to Zhengchong (persistent palpitations), and it is erroneous for contemporary practitioners to distinguish them as two separate conditions.
The causes of Heart Palpitations do not exceed two types: one is Deficiency (Xu), and the other is Fluid Retention (Yin). In cases of Qi Deficiency, it arises from internal deficiency of Yang Qi, leaving the epigastrium empty; Fire Qi moves internally causing palpitations. The same applies to Blood Deficiency. In cases of retained fluids, water accumulates below the heart. Since the Heart belongs to Fire and dislikes Water, once water stagnates internally, the Heart loses its peace, resulting in palpitations. There are instances where palpitations occur due to internal deficiency of Righteous Qi after sweating, vomiting, or purging; there are cases caused by the clash of pathogenic factors; and there are severe cases involving the exhaustion of Ying and Wei circulation with knotted and intermittent pulses. Such cases require generating body fluids and nourishing blood to fill the deficiency; this perspective is derived from the study of Cold Damage.
For miscellaneous diseases, we refer to the *Neijing* (Classic of Internal Medicine): Patients with Heart Bi (Obstruction) have obstructed vessels and feel a drumming sensation in the epigastrium when vexed. Patients with Gallbladder disease experience bitter taste and vomiting of old bile, with a trembling sensation in the epigastrium and fear resembling being hunted. When the Foot-Yangming channel undergoes pathological changes, hearing the sound of wood induces sudden fright. When the Pericardium channel undergoes pathological changes, there is a strong trembling sensation in the chest. When the Kidney channel undergoes pathological changes, there is excessive fear and a heart trembling as if being hunted.
The *Yuanbing Shi* (Treatise on Original Causes of Disease) states: Due to Water deficiency and Fire prosperity, restlessness in the chest and heart occurs, termed Zhengchong. From this, we understand that Ji is a disease where the Qi of the Heart fails to move normally, disturbed by Fire Pathogens. Generally, the Heart is the Ministerial Fire (Jun Huo), and the Pericardium is the Assistant Fire (Xiang Huo). Fire belongs to Yang, and Yang is active. Beneath the Ministerial Fire, Yin Essence must sustain it; beneath the Assistant Fire, Water Qi must sustain it. When movement is sustained thus, it follows the correct path, manifesting as clarity, brightness, and vital energy. If sustenance is lacking, the Ministerial Fire becomes excessive and abnormal, transforming into vexation and heat; the Assistant Fire moves recklessly, creating both heat and agitation—does this not constitute Heart Palpitations?
Moreover, the Heart houses the Spirit (Shen). The Classics state: "The interaction of two Jings is called Shen." Also: "Blood and Qi are the Spirit of humans." Thus, Yin-Yang, Blood, and Qi are inseparable within the Heart. Now, having lost Yin, the balance tilts toward Yang. Yang, lacking sustenance, becomes scattered and chaotic, causing the spirit to tremble and be unable to find peace. In such cases, one should tonify the deficient Heart Blood to calm the Spirit. If ineffective, seek the associated organ system to subdue it, i.e., strengthen the source of Water to control the excess Yang.
Furthermore, the Fire of the Pericardium not only assists the Heart but also circulates through the Five Zang organs. Therefore, reckless movements of Qi in any Zang are driven by Fire. Consequently, diseases in any Zang can combine with the Pericardium's Fire to induce palpitations. In such cases, one must tonify or drain the specific Zang to address the root of the Fire, then regulate the Pericardium according to the situation. If Heat from other Zangs transfers to the Heart, triggering Pericardium Fire, the treatment is similar.
If Heart Qi is deficient and Kidney Water overcomes it, rising and stagnating in the heart region, one must suppress the rebellious Qi, drain the Water, and tonify Yang. If the True Water of the Left Kidney is insufficient, allowing Fire from the Right Kidney to rise and combine with the Pericardium, one must vigorously tonify the Yin of the Left Kidney to restrain it. If various internal and external pathogens cause stagnation, preventing the two Fires from venting, isolating Ying and Wei, and failing to nourish Righteous Qi, the primary treatment should focus on resolving pathogens and relieving stagnation.
If Phlegm-Fluids stagnate in the Middle Jiao, obstructing meridians and preventing smooth flow, and Stagnant Fire clashes with Phlegm in the epigastrium causing Zhengchong, one must guide out the Phlegm; once meridians are unobstructed, the disease will resolve spontaneously. Danxi stated: Zhengchong generally belongs to Blood Deficiency and Phlegm. Palpitations triggered by worry belong to Deficiency. Intermittent palpitations indicate Phlegm stirred by Fire. Thin individuals mostly suffer from Blood Deficiency; fat individuals mostly suffer from Phlegm-Fluids. True palpitations indicate low Blood volume, suitable for formulas like Siwu Tang (Four Substances Decoction) to calm the spirit.
The *Jinkui Yaolue* (Essential Prescriptions of the Golden Cabinet) states: Low food intake and high fluid consumption lead to water stagnation below the heart; severe cases result in palpitations, mild cases in shortness of breath. It also states: For palpitations below the heart, Banxia Mahuang Wan (Pinellia and Ephedra Pill) is indicated. One may also use Wendan Tang (Warm the Gallbladder Decoction), or Daotan Tang (Guide Out Phlegm Decoction) added with stir-fried Suanzaoren (Ziziphus Seed), Xiashouxing Wan (Descend Longevity Pill), Fuling Yinzi (Poria Drink), Fuling Gancao Tang (Poria and Licorice Decoction), Jiangzhu Tang (Ginger and Atractylodes Decoction), or Wuling San (Five-Ling Powder). If Fire is excessive, add Huanglian (Coptis). For knotted and intermittent pulses with palpitations, use Zhigancao Tang (Honey-Fried Licorice Decoction).
Long-term longing for loved ones, frustration with events, depletion of True Blood, and insufficiency of Heart Blood lead to Zhengchong; Yangrong Tang (Nourish the Vigor Decoction) is appropriate. Palpitations caused by Wind-Cold, Summerheat, Dampness, or obstruction of various meridians are detailed in their respective sections. If Ministerial Fire rises upward causing persistent palpitations, severe cases may present with fire blazing above, dizziness, blurred vision, tooth loss, baldness, enlarged fingers, visual hallucinations, or abdominal noises; this is caused by Minsterial Fire. Treatment should employ Ziyin Yihuo Tang (Nourish Yin and Suppress Fire Decoction). For restless heart, add herbs that nourish the Heart. If prolonged use of fire-clearing herbs fails, add Fuzi (Aconite Root) for counter-treatment, or add Renshen (Ginseng).
For those who have lost their will, due to unfulfilled desires or self-blame for errors, leading to endless regret and sighing, talking to oneself, writing in the air, and feeling lost, use Wendan Tang removing Zhuru (Bamboo Shavings), adding Renshen (Ginseng) and Baiziren (Biota Seed), each 1 qian, combined with Xia Dingzhi Wan (Settle the Will Pill), assisted by Chensha Miaoxiang San (Cinnabar and Fragrant Powder) mixed with wine.
For patients with epigastric fullness, poor appetite, constant sense of inadequacy, preference for dark places, leaning against doors, and startling upon seeing people, resembling a state of lost will, this is the disease of Beili (Lowly Fear), caused by Blood insufficiency. Renyang Rong Tang (Human Nourishment and Vigor Decoction) is suitable. For Spleen and Stomach deficiency, Gushen Jiahe San (Grain Spirit and Grain Sprout Powder) added with Danggui (Angelica Sinensis) and Huangqi (Astragalus), half qian each, is indicated.