PARTONE - Cardiovascular System Disorders
Wendy A. Ware and Jessica L. Ward PARTONE - 心血管系统疾病 Wendy A. Ware 和 Jessica L. Ward
C H A P T ER 章节
Clinical Manifestations of Cardiac Disease 临床心脏病表现
SIGNS OF HEART DISEASE 心脏病症状
Several signs can indicate the presence of heart disease, even if the animal is not clinically in “heart failure.” So-called objective signs of heart disease are, for the most part, cardiac specific. These are cardiac murmurs, rhythm disturbances, jugular pulsations, and cardiac enlargement. Notable exceptions to this generalization include murmurs that are functional (nonpathologic) in nature and the normal rhythm irregularity of sinus arrhythmia. Other clinical signs may indicate heart disease but can occur with noncardiac diseases as well. These include syncope, excessively weak or strong arterial pulses, cough or respiratory difficulty, exercise intolerance, abdominal distention, and cyanosis. Further evaluation using thoracic radiography, cardiac biomarker tests, echocardiography, electrocardiography (ECG), and sometimes other tests usually is indicated when signs consistent with cardiovascular (CV) disease are present. 一些迹象可以表明存在心脏病，即使动物没有出现临床上的“心力衰竭”。所谓的心脏病客观迹象，大部分是心脏特异性。这些包括心脏杂音、心律失常、颈动脉搏动和心脏增大。这一概括的显著例外包括功能性（非病理性）的心脏杂音和窦性心律不齐的正常节律不规则。其他临床迹象可能表明心脏病，但也可能伴随非心脏病出现。这些包括晕厥、动脉脉搏过弱或过强、咳嗽或呼吸困难、运动不耐受、腹部膨胀和发绀。当出现符合心血管（CV）疾病的迹象时，通常需要进行胸部 X 光检查、心脏生物标志物测试、超声心动图、心电图（ECG）以及有时其他检查的进一步评估。
SIGNS OF HEART FAILURE 心衰症状
Heart failure generally is considered to occur when the heart cannot adequately meet the body’s circulatory needs or can do so only with high filling (venous) pressures. Not all animals with heart disease will develop heart failure. Of those that do, the majority show clinical signs (Box 1.1) related to high venous pressure behind one or both ventricles (congestive signs), and some also manifest signs of inadequate blood ejection from the heart (low output signs). Congestive signs associated with right-sided heart failure stem from systemic venous hypertension and the resulting increase in systemic capillary hydrostatic pressure. High left-heart filling pressure causes pulmonary venous engorgement and edema. Signs of biventricular failure develop in some animals. Chronic leftsided congestive heart failure (CHF) can promote the development of right-sided congestive signs when pulmonary venous hypertension markedly raises pulmonary arterial 心衰通常被认为是当心脏无法充分满足身体循环需求或只能在高充盈（静脉）压力下满足时发生的。并非所有患有心脏病的动物都会发展成心衰。其中，大多数表现出与一个或两个心室后高静脉压力相关的临床体征（表 1.1），表现为充血体征，一些动物还表现出心脏血液排出不足的迹象（低输出体征）。与右侧心衰相关的充血体征源于全身静脉高血压和由此引起的全身毛细血管静水压增加。高左心充盈压力导致肺静脉充血和水肿。某些动物会出现双心室衰竭的迹象。慢性左侧充血性心力衰竭（CHF）可以促进右侧充血体征的发展，当肺静脉高血压显著升高肺动脉
pressure. Signs of low cardiac output are similar regardless of which ventricle is affected, because output from the left heart is coupled to that from the right heart. Heart failure is discussed further in Chapter 3 and within the context of specific diseases. 血压。低心输出量的症状无论受影响的哪个心室都相似，因为左心输出与右心输出是相互关联的。心力衰竭在第三章中进一步讨论，并在特定疾病的背景下进行讨论。
WEAKNESS AND EXERCISE INTOLERANCE 虚弱和运动耐受性不佳
Animals with heart failure often cannot adequately raise cardiac output to sustain increased levels of activity. Furthermore, vascular and metabolic changes that occur over time impair skeletal muscle perfusion during exercise and contribute to reduced exercise tolerance. Increased pulmonary vascular pressure and edema also lead to poor exercise ability. Episodes of exertional weakness or collapse can relate to these changes or to an acute decrease in cardiac output caused by arrhythmias (Box 1.2). 動物患有心衰時，往往無法充分提高心輸出量以維持活動量的增加。此外，隨著時間推移發生的血管和代謝變化會在運動時損害骨骼肌灌流，並導致運動耐受力降低。肺血管壓力增加和浮腫也會導致運動能力下降。勞累性虛弱或昏厥發作可能與這些變化相關，或與由心律失常引起的急性心輸出量降低相關（框 1.2）。
SYNCOPE 晕厥
Syncope is characterized by transient unconsciousness, with loss of postural tone (collapse), from insufficient oxygen or glucose delivery to the brain. Various cardiac and noncardiac abnormalities can cause syncope and intermittent weakness (see Box 1.2). Syncope can be confused with seizure episodes. A careful description of the animal’s behavior or activity before the collapse event, during the event itself, and following the collapse, as well as a drug history, can help the clinician differentiate among syncopal attacks, episodic weakness, and true seizures. Syncope often is associated with exertion or excitement. The actual event can include rear limb weakness or sudden collapse, lateral recumbency, stiffening of the forelimbs with opisthotonos, and micturition (Fig. 1.1). Vocalization is common; however tonic/clonic motion, facial fits, and defecation are not. An aura (which often occurs before seizure activity), postictal dementia, and neurologic deficits are not expected in dogs and cats with CV syncope. Sometimes profound hypotension or asystole causes hypoxic “convulsive syncope,” with seizure-like 晕厥的特征是短暂的意识丧失，伴有姿势张力丧失（跌倒），由大脑缺氧或葡萄糖供应不足引起。各种心脏和非心脏异常可导致晕厥和间歇性无力（见框 1.2）。晕厥可能与癫痫发作混淆。仔细描述动物在跌倒事件前、事件本身以及跌倒后的行为或活动，以及药物史，可以帮助临床医生区分晕厥发作、间歇性无力和真正的癫痫。晕厥通常与劳累或兴奋有关。实际事件可能包括后肢无力或突然跌倒、侧卧、前肢僵直伴有角弓反张和排尿（图 1.1）。发声是常见的；然而，强直/阵挛运动、面部痉挛和排便则不常见。在 CV 晕厥的狗和猫中，通常不期望出现前驱症状（通常在癫痫活动前发生）、发作后痴呆和神经功能障碍。有时严重低血压或心室停搏会导致缺氧“惊厥性晕厥”，伴有类似癫痫的
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BOX 1.1 盒 1.1
Clinical Signs of Heart Failure 临床心力衰竭的体征
Congestive Signs－Left（ uarr\uparrow Left Heart Filling Pressure） 充血征象－左侧（ uarr\uparrow 左心充盈压）
FIG 1.1 图 1.1
Syncope in a Doberman Pinscher with paroxysmal ventricular tachycardia．Note the extended head and neck with stiffened forelimbs．Involuntary micturition also occurred，followed shortly by return of consciousness and normal activity． 晕厥伴发于杜宾犬的阵发性室性心动过速。注意头部和颈部延长，前肢僵硬。随后出现不自主排尿，紧接着意识恢复和正常活动
activity or twitching；however，these convulsive syncopal epi－ sodes are preceded by loss of muscle tone．Presyncope，where reduced brain perfusion（or substrate delivery）is not severe enough to cause unconsciousness，may appear as transient ＂wobbliness＂or weakness，especially in the rear limbs． 活动或抽搐；然而，这些惊厥性晕厥发作之前会出现肌肉张力下降。晕厥前期，由于大脑灌注（或底物输送）减少但不足以导致意识丧失，可能表现为短暂的“摇晃”或无力，尤其是在后肢
Causes of Syncope or Intermittent Weakness 原因：晕厥或间歇性虚弱
Cardiovascular Causes 心血管原因
Bradyarrhythmias（second－or third－degree AV block， sinus arrest，sick sinus syndrome，atrial standstill） Tachyarrhythmias（paroxysmal atrial or ventricular tachycardia，reentrant supraventricular tachycardia， atrial fibrillation） 心动过缓（二度或三度房室传导阻滞，窦性停搏，病态窦房结综合征，心房静止）心动过速（阵发性房性或室性心动过速，折返性室上性心动过速，心房颤动）
Congenital ventricular oufflow obstruction（pulmonic stenosis，subaortic stenosis） 先天性室间隔缺损（肺动脉狭窄，主动脉瓣下狭窄）
Acquired ventricular oufflow obstruction（heartworm disease and other causes of pulmonary hypertension， hypertrophic obstructive cardiomyopathy，intracardiac tumor，thrombus） 获得性心室流出道梗阻（心丝虫病和其他原因引起的肺动脉高压、肥厚型梗阻性心肌病、心内肿瘤、血栓）
Cyanotic heart disease（tetralogy of Fallot，pulmonary hypertension，and＂reversed＂shunt） 青紫型心脏病（法洛四联症、肺动脉高压和“逆转”分流）
Impaired forward cardiac output（severe valvular insufficiency，dilated cardiomyopathy，myocardial infarction or inflammation） 心输出量降低（严重瓣膜反流，扩张型心肌病，心肌梗死或炎症）
Impaired cardiac filling（e．g．，cardiac tamponade， constrictive pericarditis，hypertrophic or restrictive cardiomyopathy，intracardiac tumor，thrombus） 心功能不全（例如，心包填塞，缩窄性心包炎，肥厚型或限制型心肌病，心内肿瘤，血栓）
Cardiovascular drugs（diuretics，vasodilators） 心血管药物（利尿剂，血管扩张剂）
Neurocardiogenic reflexes（vasovagal，cough－syncope， other situational syncope） 神经源性反射（血管迷走性，咳嗽-晕厥，其他情境性晕厥）
（Narcolepsy，cataplexy） （嗜睡症，猝倒症） AVA V ，Atrioventricular． AVA V ，心房室．
Tests to explore the cause of intermittent weakness or syncope usually include ECG recordings（during rest，exer－ cise，and／or after exercise or a vagal maneuver），complete blood count（CBC），serum biochemical analysis（including electrolytes and glucose），heartworm testing，neurologic examination，thoracic radiographs，and echocardiography． Other studies for neuromuscular or neurologic disease also may be valuable．Intermittent cardiac arrhythmias that are not apparent on resting ECG may be uncovered by ambula－ tory ECG monitoring，using a 24 －hour Holter，event，or 检查间歇性虚弱或晕厥的原因通常包括心电图记录（在休息时、运动中、运动后或进行迷走神经操作后），全血计数（CBC），血清生化分析（包括电解质和葡萄糖），心丝虫检测，神经系统检查，胸部 X 光片和超声心动图。对于神经肌肉或神经疾病的其他研究也可能有价值。在静息心电图上不明显的心律失常可能通过 24 小时 Holter、事件或便携式心电图监测被发现
implantable loop recording device. In-hospital continuous ECG monitoring for a period of time sometimes reveals a culprit arrhythmia also. 植入式环状记录装置。住院期间持续心电图监测有时也会揭示出罪魁祸首的心律失常。
Cardiovascular Causes of Syncope 心源性晕厥原因
Various arrhythmias, obstruction to ventricular outflow, cyanotic congenital heart defects, and acquired diseases that impair cardiac output are the usual causes of CV syncope. Activation of vasodepressor reflexes and excessive dosages of CV drugs also can induce syncope. Arrhythmias that provoke syncope usually are associated with either very fast or very slow heart rates and can occur with or without identifiable underlying organic heart disease. Ventricular outflow obstruction can provoke syncope or sudden weakness if cardiac output becomes inadequate during exercise or if high systolic pressure activates ventricular mechanoreceptors, causing inappropriate reflex bradycardia and hypotension. Both dilated cardiomyopathy and severe mitral insufficiency can impair forward cardiac output, especially during exertion. Vasodilator and diuretic drugs can induce syncope if given in excess. 各种心律失常、心室流出受阻、青紫型先天性心脏病和影响心输出量的获得性疾病是 CV 晕厥的常见原因。血管舒缩反射的激活和 CV 药物的过量使用也可能引起晕厥。引起晕厥的心律失常通常与非常快或非常慢的心率相关，可能伴有或无可识别的潜在有机性心脏病。心室流出受阻如果在运动时心输出量不足或如果高收缩压激活心室机械感受器，导致不适当的反射性心动过缓和低血压，可能会引起晕厥或突然虚弱。扩张型心肌病和严重二尖瓣关闭不全都可能损害前向心输出量，尤其是在用力时。如果过量使用，血管扩张剂和利尿剂也可能引起晕厥。
Syncope caused by abnormal peripheral vascular and/or neurologic reflex responses is not well defined in animals, but is thought to occur in some patients. Syncope associated with sudden bradycardia after a burst of sinus tachycardia has been documented, especially in small breed dogs with advanced atrioventricular (AV) valve disease; excitement often precipitates such an episode. Doberman Pinschers and Boxers similarly may experience syncope after sudden bradycardia. Postural hypotension and hypersensitivity of carotid sinus receptors infrequently can provoke syncope by inappropriate peripheral vasodilation and bradycardia. 晕厥由异常的外周血管和/或神经反射反应引起，在动物中定义不明确，但认为在某些患者中会发生。在窦性心动过速爆发后突然出现心动过缓的晕厥已有记录，特别是在患有晚期心房室（AV）瓣膜疾病的小型犬中；兴奋往往诱发此类发作。杜宾犬和拳师犬也可能在突然心动过缓后出现晕厥。姿势性低血压和颈动脉窦受体的过度敏感性偶尔可以通过不适当的周围血管扩张和心动过缓引起晕厥。
Fainting associated with a coughing fit (cough syncope or “cough-drop”) occurs in some dogs with marked left atrial (LA) enlargement and bronchial compression, as well as in dogs with primary respiratory disease. Several mechanisms have been proposed, including an acute decrease in cardiac filling and output during the cough, peripheral vasodilation after the cough, and increased cerebrospinal fluid pressure with intracranial venous compression. Severe pulmonary disease, anemia, certain metabolic abnormalities, and primary neurologic diseases also can cause collapse that resembles CV syncope. 晕厥与咳嗽发作（咳嗽性晕厥或“咳嗽糖”）在某些左心房（LA）显著扩大和支气管受压的狗以及患有原发性呼吸系统疾病的狗中发生。已提出几种机制，包括咳嗽时心脏充盈和输出量的急性下降，咳嗽后的外周血管扩张，以及颅内静脉受压时脑脊液压力增加。严重的肺部疾病、贫血、某些代谢异常和原发性神经系统疾病也可能导致类似 CV 晕厥的虚脱。
COUGH AND OTHER RESPIRATORY SIGNS 咳嗽及其他呼吸征象
CHF in dogs produces tachypnea, respiratory distress, and sometimes coughing. These signs also can occur with the pulmonary vascular pathology and pneumonitis of heartworm disease in both dogs and cats. Noncardiac conditions, including diseases of the upper and lower airways, pulmonary parenchyma (including noncardiogenic pulmonary edema), pulmonary vasculature, and pleural space, as well as certain nonrespiratory conditions, also should be considered in patients with cough, tachypnea, or dyspnea (see Chapter 19). CHF 在狗身上会导致呼吸急促、呼吸困难，有时还会咳嗽。这些症状也可能出现在狗和猫的心丝虫病的肺血管病变和肺炎中。在患有咳嗽、呼吸急促或呼吸困难的患者中，还应考虑非心脏条件，包括上下呼吸道疾病、肺实质（包括非心源性肺水肿）、肺血管和胸腔空间，以及某些非呼吸系统疾病（见第 19 章）。
The cough associated with cardiogenic pulmonary edema in dogs often is soft and moist; it sometimes sounds like gagging. Cats, in contrast, rarely cough from pulmonary edema. Tachypnea progressing to dyspnea occurs in both species. Pleural and pericardial effusions occasionally are associated with coughing as well. Mainstem bronchus collapse or compression associated with severe LA enlargement can stimulate a dry or hacking cough in dogs with chronic mitral valve disease, even when pulmonary edema or congestion is absent. Concurrent bronchomalacia is likely to be a contributing factor in these cases. A heart base tumor, enlarged hilar lymph nodes, or other masses that impinge on an airway also can stimulate this type of cough. 与狗的心源性肺水肿相关的咳嗽通常是柔软湿润的；有时听起来像干呕。相比之下，猫很少因肺水肿而咳嗽。两种物种都会出现呼吸急促进展为呼吸困难。偶尔，胸腔积液和心包积液也与咳嗽有关。主支气管塌陷或压迫与严重左心室扩大相关，可以刺激患有慢性二尖瓣疾病的狗出现干咳或阵咳，即使没有肺水肿或充血。在这些病例中，支气管软化可能是影响因素之一。心脏基底肿瘤、扩大的肺门淋巴结或其他压迫气道的肿块也可能刺激这种类型的咳嗽。
When respiratory signs have a cardiac cause, other evidence of heart disease usually is evident, such as generalized cardiomegaly, LA enlargement, pulmonary venous congestion, lung infiltrates that resolve with diuretic therapy, or a positive heartworm test. Findings on physical examination, thoracic radiographs, cardiac biomarker assays, echocardiogram, and sometimes an ECG, help in differentiating cardiac from noncardiac causes. 当呼吸征象由心脏原因引起时，通常会有其他心脏病证据，如普遍性心脏肥大、左心室增大、肺静脉淤血、利尿剂治疗后消退的肺浸润或阳性心丝虫检测。体格检查、胸部 X 光片、心脏生物标志物检测、超声心动图以及有时心电图，有助于区分心脏原因和非心脏原因。
CARDIOVASCULAR EXAMINATION 心血管检查
The medical history (Box 1.3) is an important part of the CV evaluation and can help guide the choice of diagnostic tests because it may suggest various cardiac or noncardiac diseases. The patient’s signalment is useful because some 病史（1.3 框）是简历评估的重要组成部分，因为它可能提示各种心脏病或非心脏病，因此有助于指导诊断测试的选择。患者的病史信息是有用的，因为一些
國 BOX 1.3 国 盒 1.3
Important Historic Information 重要历史信息
Signalment (age, breed, gender)? 信号特征（年龄、品种、性别）？
Vaccination status? 疫苗接种情况？
What is the diet? Have there been any recent changes in food or water consumption? 饮食是什么？最近有没有食物或水摄入的任何变化？
Where was the animal obtained? 动物是从哪里获得的？
Is the pet housed indoors or outdoors? 宠物是养在室内还是室外？
How much time is spent outdoors? Supervised? 户外花费多少时间？是否有人看管？
What activity level is normal? Does the animal tire easily now? 什么活动水平是正常的？动物现在容易疲劳吗？
Has there been any coughing? When? Describe episodes. 有咳嗽吗？什么时候？描述一下发作情况。
Has there been any excessive or unexpected panting or heavy breathing? 有沒有出現過過度或意外的喘息或呼吸困難？
Has there been any vomiting or gagging? Diarrhea? 有呕吐或干呕吗？腹泻？
Have there been any recent changes in urinary habits? 有最近尿习惯的变化吗？
Have there been any episodes of fainting or weakness? 有出现过晕厥或虚弱的情况吗？
Do the tongue/mucous membranes always look pink, especially during exercise? 舌/黏膜是否总是呈现粉红色，尤其是在运动时？
Have there been any recent changes in attitude or activity level? 有最近在态度或活动水平上有所改变吗？
Are medications being given for this problem? What? How much? How often? Do they help? 这些药物是用来治疗这个问题的吗？什么？多少？多久一次？有帮助吗？
Have medications been used in the past for this problem? What? How much? Were they effective? 过去是否使用过药物来治疗这个问题？什么药物？用量多少？效果如何？
