Cardiology


CLINICAL CARDIOLOGY CONCEPTS
for the dog and cat

Michael R. O'Grady, DVM, MSc, Diplomate ACVIM (Cardiology)
M. Lynne O'Sullivan, DVM, DVSc, Diplomate ACVIM (Cardiology)

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Available Sections

    1.  Cardiovascular Physiology [detailed listing]
    2.  Pathophysiology [detailed listing]
    3.  Clinical Evaluation of Heart Disease [detailed listing]
    4.  Thoracic Radiograph Tutorial [detailed listing]
    5.  General Therapeutic Concepts [detailed listing]
    6.  Acquired Heart Disease [detailed listing]
    7.  Heartworm Disease [detailed listing]
    8.  Congenital Heart Disease [detailed listing]
    9.  Electrocardiology [detailed listing]
    10.  Echocardiography [detailed listing]

Cardiovascular Physiology
  Structure and Function
         Go -> Anatomy of the cardiovascular system
         Go -> What is the role of the cardiovascular system?
         Go -> What is the role of the heart?
         Go -> What is the role of the systemic arterial system?
         Go -> What is the role of the systemic venous system?
         Go -> What is the role of the pulmonary arterial system?
         Go -> What is the role of the pulmonary venous system?
         Go -> How is the function of the pulmonary arterial tree different from the systemic arterial tree?
         Go -> How does the anatomy of the pulmonary arterial tree differ from the systemic arterial tree such that it supports the difference in function between the two systems?
         Go -> What is the role of the capillary beds?
         Go -> What is the role of Starling forces?
         Go -> What are the functions of the components of the heart?
         Go -> What components of the cardiovascular system could be responsible for cardiovascular disease - or - where within the cardiovascular system could malfunction occur?
 
  Edema Formation
         Go -> What is edema?
         Go -> Where does edema develop?
         Go -> What factors promote the development of edema?
 
  Lymphatics
         Go -> What is the role of the lymphatic system?
         Go -> How is lymph formed?
         Go -> What factors promote the flux of fluid?
         Go -> The student should be familiar with:
 
  The Microcirculation
         Go -> What are the transcapillary exchange mechanisms?
         Go -> Identify the components of the microcirculation
 
  Vascular Control
         Go -> What are the factors that control BP?
         Go -> What affects organ flow?
         Go -> What factors affect peripheral vascular resistance (also called total peripheral resistance or systemic vascular resistance)?
         Go -> What is the role of Baroreceptors (carotid/aortic arch) in BP control?
         Go -> Role of atrial volume receptors:
         Go -> What is syncope?
         Go -> What are the causes of syncope?
         Go -> What is the role of Natriuretic Peptide?
 
  The Cardiac Cycle
         Go -> da
         Go -> Identify the 3 components to diastole.
         Go -> Wiggers Diagram:
 
  Compensation for Circulatory Failure
         Go -> How does the cardiovascular system respond to failure?
         Go -> What is the response of the circulatory system in the case of Shock?
         Go -> Why is the shock response counter productive for cases of cardiac disease causing a fall in BP?
         Go -> How is the shock response counter-productive for cases of cardiac disease causing a fall in BP?
 
  The Determinants of Myocardial Performance
         Go -> What are the determinants of myocardial performance?
         Go -> What is myocardial oxygen demand?
         Go -> What factors affect MVO2?
         Go -> What is Wall Stress?
         Go -> What is Stroke Volume?
         Go -> What is Cardiac Output?
         Go -> How does heart rate affect myocardial performance?
         Go -> What factors affect heart rate?
         Go -> How do baroreceptors affect cardiac function?
         Go -> How might an abnormality of heart rate manifest?
         Go -> What is preload?
         Go -> How is preload measured?
         Go -> How does preload affect myocardial performance?
         Go -> What is The Frank Starling Law of the heart?
         Go -> What factors affect preload?
         Go -> How might an abnormality of preload manifest?
         Go -> How does the autonomic nervous system affect preload?
         Go -> What is afterload?
         Go -> What factors affect afterload?
         Go -> What factors determine blood pressure?
         Go -> What is pulse pressure?
         Go -> What is perfusion pressure?
         Go -> What factors affect the physical examination assessment of systemic BP?
         Go -> How is afterload measured?
         Go -> How does afterload affect myocardial performance?
         Go -> What factors determine arterial resistance?
         Go -> How might an abnormality of afterload manifest?
         Go -> How does the autonomic nervous system affect afterload?
         Go -> What is contractility?
         Go -> What factors affect contractility?
         Go -> How is contractility measured?
         Go -> How does contractility affect myocardial performance?
         Go -> How might an abnormality of contractility manifest?
         Go -> How does the autonomic nervous system affect contractility?
         Go -> What is distensibility?
         Go -> What factors affect distensibility?
         Go -> How is distensibility measured?
         Go -> How does distensibility affect myocardial performance?
         Go -> How might an abnormality of distensibility manifest?
         Go -> How does the autonomic nervous system affect distensibility?
         Go -> What is synergy of contraction?
         Go -> How does dyssynergy of contraction affect myocardial performance?
         Go -> How might an abnormality of synergy of contraction manifest?
         Go -> How might an abnormality of synergy of contraction be resolved?
         Go -> How does the autonomic nervous system affect synergy of contraction?
 
  Neuro-Control of the Heart and Vasculature
         Go -> What is the role of the autonomic nervous system?
         Go -> What is the effect of activation of the autonomic nervous system?
         Go -> What is the messenger of the SNS and PNS:
         Go -> How does the SNS mediate its action?
         Go -> How does the PNS mediate its action?
         Go -> How do Beta receptors work?
         Go -> How do Alpha receptors work?
         Go -> How do Muscarinic receptors work?
         Go -> Discuss the regulation of G protein coupled receptors:
 
  Electro - Mechanical Association:
         Go -> What occurs during the action potential with respect to Ca ions?
         Go -> How does the process of vascular smooth muscle contraction differ from myocardial contraction?
         Go -> Describe the process of relaxation.
         Go -> Why might one want to increase contractility?
         Go -> How can contractility be enhanced?
         Go -> How does contractility occur?
         Go -> What are the contractile proteins? Regulatory proteins? Structural proteins?
         Go -> How does calcium mediate contraction?
         Go -> What is the significance of the concept calcium induced calcium release?
         Go -> What are the following terms:
 
  The Electrical Side of the Heart
         Go -> What is the role of the electrical system of the heart?
         Go -> What are the components of the electrical system in the heart?
         Go -> How does the horse and cow differ from the dog and cat with respect to the anatomy of their conduction system?
         Go -> What is occurring during the components of the ECG?
         Go -> Identify the lead systems used to obtain an ECG;
         Go -> What is a lead?
         Go -> In what capacity is the ECG a valuable tool in the assessment of cardiovascular disease in domestic animals?
         Go -> What is an action potential?
         Go -> How does a myocardial action potential differ from a skeletal muscle action potential?
         Go -> What are the components of the myocardial action potential?
         Go -> What is the refractory period?
         Go -> Myocardial cells can be divided into automatic and non-automatic cells.
 
  Causes of Heart Failure
         Go -> Where is the abnormality?
 

Pathophysiology
  General
         Go -> What is heart failure?
         Go -> What is congestive heart failure?
         Go -> How is heart disease different from heart failure?
         Go -> What is myocardial oxygen consumption?
         Go -> How do changes in myocardial oxygen consumption alter cardiac performance?
         Go -> What are the determinants of cardiac output?
         Go -> What is preload?
         Go -> How do changes in preload change cardiac performance?
         Go -> How are changes in preload detected on physical examination?
         Go -> What is afterload?
         Go -> How do changes in afterload change cardiac performance?
         Go -> How are changes in afterload detected on physical examination?
         Go -> What is contractility?
         Go -> How do changes in contractility change cardiac performance?
         Go -> How are changes in contractility detected on physical examination?
         Go -> How do changes in heart rate (HR) change cardiac performance?
         Go -> What is distensibility?
         Go -> How do changes in distensibility change cardiac performance?
         Go -> How are changes in distensibility detected on physical examination?
         Go -> What is synergy of contraction?
         Go -> How do changes in synergy of contraction change cardiac performance?
         Go -> How are disorders characterized by dyssynergy of contraction detected on physical examination?
         Go -> What are the compensatory measures that occur in heart failure?
         Go -> List the mechanisms that promote arterial vasoconstriction in Heart Failure
 

Clinical Evaluation of Heart Disease
  The Physical Exam
         Go -> What are the historical findings in heart failure?
         Go -> What are the physical examination findings in heart failure?
         Go -> What are pulse deficits?
         Go -> What is a hepato-jugular reflux (HJR) response?
         Go -> How do I interpret the arterial pulse?
         Go -> What diagnostic aids are available to evaluate the heart?
         Go -> What abnormalities can be detected by cardiac palpation?
         Go -> What can be learned from auscultation?
         Go -> What are some important technical aspects about stethoscopes and auscultation?
         Go -> What is the origin of the normal heart sounds, S1 and S2?
         Go -> What are heart murmurs?
         Go -> What causes heart murmurs?
         Go -> Can heart murmurs occur in the absence of anatomic or physiologic changes to the heart?
         Go -> How does the detection of a heart murmur help us determine the type of heart disease?
         Go -> What are some special considerations for heart murmurs in cats?
         Go -> What other abnormalities may be detected by cardiac auscultation and what is their significance?
 
  Radiographic Evaluation
         Go -> Can radiography diagnose heart failure and how?
         Go -> What are the radiographic features of pulmonary venous distention and pulmonary edema?
         Go -> What other cardiac abnormalities can be diagnosed by radiography?
         Go -> What are the radiographic features of cardiac chamber enlargement?
         Go -> How can vertebral heart size (VHS) be used to evaluate heart size?
         Go -> What abnormalities of the great vessels might be identified by routine radiography?
         Go -> What radiographic features might suggest the presence of heartworm disease?
         Go -> Can radiography diagnose pericardial effusion?
 
  Electrocardiographic Evaluation
         Go -> Can electrocardiography diagnose heart failure and how?
         Go -> What abnormalities can be diagnosed by the ECG?
 
  Hematologic Evaluation
         Go -> Can blood work diagnose heart failure?
         Go -> What cardiac abnormalities can be diagnosed by blood work?
         Go -> Why is BNP a potentially useful test in veterinary medicine?
 
  Echocardiographic Evaluation
         Go -> Can echocardiography diagnose heart failure?
         Go -> What other abnormalities can be diagnosed by echocardiography?
         Go -> What is Doppler echocardiography? How is it useful?
 

Thoracic Radiograph Tutorial
  Thoracic Radiograph Evaluation
         Go -> Radiopacity and Radiolucency
         Go -> How does air appear radiographically?
         Go -> Why do we do Thoracic Radiographs in Cardiology?
         Go -> The Role of Starling Forces
         Go -> The Role of the Lymphatic System
 
  Thoracic Radiograph Evaluation of Left-Sided Heart Failure
         Go -> Thoracic Radiograph Evaluation of Left-Sided Heart Failure
         Go -> How do we assess pulmonary venous engorgement radiographically?
         Go -> How do peribronchial patterns appear radiographically?
         Go -> How do air bronchograms appear radiographically?
         Go -> What do lobar signs look like radiographically?
 
  Thoracic Radiograph Evaluation of Right-Sided Heart Failure
         Go -> Thoracic Radiograph Evaluation of Right-Sided Heart Failure
         Go -> What do Fissure lines look like radiographically?
         Go -> How does one differentiate a fissure line from a lobar sign?
         Go -> What does leafing of the lung lobes look like radiographically?
 
  Other Thoracic Radiograph Observations
         Go -> What do Cotton-like Densities look like radiographically?
 

General Therapeutic Concepts
  Therapy of Heart Failure
         Go -> What Are Some General Considerations in the Therapy of Heart Failure?
         Go -> How is the Response to Heart Failure like that of Shock?
         Go -> Outline the classes of drugs used to treat heart failure.
         Go -> List common diuretics used to treat heart failure and list their advantages and disadvantages.
         Go -> List common venodilators used to treat heart failure and outline their advantages and disadvantages.
         Go -> List common arteriolar dilators used to treat heart failure and outline their advantages and disadvantages.
         Go -> List common angiotensin converting enzyme inhibitors and outline their advantages and disadvantages.
         Go -> List combined vasodilators used to treat heart failure and outline their advantages and disadvantages.
         Go -> How can drug induced hypotension be detected?
         Go -> List positive inotropes used to treat heart failure and outline their advantages and disadvantages.
         Go -> List negative inotropes used to treat heart failure and outline their advantages and disadvantages.
         Go -> List beta-blockers used to treat heart failure and outline their advantages and disadvantages.
         Go -> What have we learned from the veterinary clinical heart failure trials?
         Go -> How should I treat congestive heart failure?
         Go -> How should I treat the patient with fulminant pulmonary edema?
         Go -> How would the authors treat the patient with severe congestive heart failure on an outpatient basis?
         Go -> How should the patient with refractory heart failure or refractory ascites due to systolic dysfunction be treated?
         Go -> Should I treat the patient that has heart disease without heart failure with the goal of improving survival?
         Go -> What is the prognosis with therapy for heart failure?
 

Acquired Heart Disease
  General
         Go -> Dog Breed Predilections
         Go -> Chronic Mitral Valve Insufficiency (CMVI) - What is it?
         Go -> How does chronic mitral valve insufficiency present?
         Go -> How is chronic mitral valve insufficiency diagnosed?
         Go -> How is chronic mitral valve insufficiency treated?
         Go -> What is the prognosis with chronic mitral valve insufficiency?
         Go -> What is cardiomyopathy?
         Go -> What is the etiology of canine dilated cardiomyopathy (DCM)?
         Go -> How does canine dilated cardiomyopathy (DCM) present?
         Go -> How is canine dilated cardiomyopathy (DCM) diagnosed?
         Go -> How is canine dilated cardiomyopathy treated?
         Go -> What is the prognosis with canine dilated cardiomyopathy (DCM)?
         Go -> What is feline dilated cardiomyopathy?
         Go -> What is the etiology of feline dilated cardiomyopathy?
         Go -> How does feline dilated cardiomyopathy present?
         Go -> How is feline dilated cardiomyopathy diagnosed?
         Go -> How is feline dilated cardiomyopathy treated?
         Go -> What is the prognosis with feline dilated cardiomyopathy?
         Go -> What is feline thromboembolic disease?
         Go -> What is feline hypertrophic cardiomyopathy?
         Go -> How does feline hypertrophic cardiomyopathy (HCM) present?
         Go -> How is feline hypertrophic cardiomyopathy (HCM) diagnosed?
         Go -> How is feline hypertrophic cardiomyopathy treated?
         Go -> What is the prognosis for feline hypertrophic cardiomyopathy (HCM)?
         Go -> What is feline restrictive cardiomyopathy?
         Go -> Are there other forms of feline cardiomyopathy?
         Go -> What is feline hyperthyroidism?
         Go -> How does feline hyperthyroidism present?
         Go -> How is feline hyperthyroidism diagnosed?
         Go -> How is feline hyperthyroidism treated?
         Go -> What is the prognosis with feline hyperthyroidism?
         Go -> How does Boxer Cardiomyopathy differ from canine dilated cardiomyopathy?
         Go -> Does hypertrophic cardiomyopathy occur in the dog?
         Go -> Pericardial disease: what types of disorders are there?
         Go -> Pericardial effusion - What is the abnormality?
         Go -> How does pericardial effusion present?
         Go -> How is pericardial effusion diagnosed?
         Go -> What is cardiac tamponade?
         Go -> How is pericardial effusion treated?
         Go -> What is the prognosis with pericardial effusion?
         Go -> What is constrictive pericardial disease?
         Go -> What is pericardial disease in the cat?
         Go -> Bacterial endocarditis - What is the abnormality?
         Go -> How does bacterial endocarditis present?
         Go -> How is bacterial endocarditis diagnosed?
         Go -> How is bacterial endocarditis treated?
         Go -> What is the prognosis with bacterial endocarditis?
 

Heartworm Disease
  General
         Go -> What is canine Heartworm Disease?
         Go -> Discuss the mechanisms of disease induced by heartworm infection.
         Go -> How does canine Heartworm Disease present?
         Go -> How is canine Heartworm Disease diagnosed?
         Go -> How is canine Heartworm Disease treated?
         Go -> What is the prognosis with canine Heartworm Disease?
         Go -> How does feline heartworm disease differ from canine heartworm disease?
         Go -> What is Occult Heartworm Disease?
         Go -> How does Occult Heartworm Disease present?
         Go -> How is Occult Heartworm Disease diagnosed?
         Go -> How is Occult Heartworm Disease treated?
         Go -> What is the prognosis with Occult Heartworm Disease?
 

Congenital Heart Disease
  General
         Go -> Dog Breed Predilections
         Go -> Congenital heart disease - general features about shunts
         Go -> Patent ductus arteriosus: What is the abnormality?
         Go -> How does patent ductus arteriosus present?
         Go -> How is patent ductus arteriosus diagnosed?
         Go -> How is patent ductus arteriosus treated?
         Go -> What is the prognosis with patent ductus arteriosus?
         Go -> Aortic Stenosis: What is the abnormality?
         Go -> How does aortic stenosis present?
         Go -> How is aortic stenosis diagnosed?
         Go -> How is aortic stenosis treated?
         Go -> What is the prognosis with aortic stenosis?
         Go -> Pulmonic Stenosis: What is the abnormality?
         Go -> How does pulmonic stenosis present?
         Go -> How is pulmonic stenosis diagnosed?
         Go -> How is pulmonic stenosis treated?
         Go -> What is the prognosis with pulmonic stenosis?
         Go -> Ventricular Septal Defect: What is the abnormality?
         Go -> How does ventricular septal defect present?
         Go -> How is ventricular septal defect diagnosed?
         Go -> How is ventricular septal defect treated?
         Go -> What is the prognosis with ventricular septal defect?
         Go -> Tetralogy of Fallot - What is the abnormality?
         Go -> How does Tetralogy of Fallot present?
         Go -> How is Tetralogy of Fallot diagnosed?
         Go -> How is Tetralogy of Fallot treated?
         Go -> What is the prognosis with Tetralogy of Fallot?
         Go -> How does congenital heart disease of cats differ from that of dogs?
         Go -> What are the causes for syncope?
 

Electrocardiology
  General
         Go -> What is a P wave? What electrocardiographic event does this represent?
         Go -> What is the PR interval? What is the significance of the PR interval?
         Go -> What is the significance of the QRS complex? How are a Q, R, S, and QS different?
         Go -> What is a T wave? What is the significance of a T wave?
         Go -> What is the significance of a positive deflection in a lead? Of a negative deflection in a lead?
         Go -> What is the frontal plane diagram? What are the horizontal plane leads?
         Go -> What is the significance of the MEA of the QRS complex?
         Go -> Why should I bother determining the MEA?
         Go -> What is a sinus rhythm?
         Go -> What is a sinus arrhythmia?
         Go -> What is a wandering atrial pacemaker?
 
  Chamber Enlargement
         Go -> Approach to the ECG to determine chamber enlargement
         Go -> What is the significance of a P wave that is too tall or too wide?
         Go -> What are the electrocardiographic criteria of left ventricular enlargement?
         Go -> What are the electrocardiographic criteria of left ventricular concentric hypertrophy?
         Go -> What is the electrocardiographic evidence of right ventricular enlargement?
 
  Normal ECG Parameters
         Go -> Normal ECG Diagram
         Go -> Normal Small Animal Electrocardiographic Parameters
 
  Dysrhythmias
         Go -> Approach to the ECG to assess dysrhythmias.
 
  Bradycardias
         Go -> What is bradycardia?
         Go -> What is sinus bradycardia?
         Go -> What is heart block?
         Go -> What is 1st degree Heart Block?
         Go -> What is 2nd degree Heart Block?
         Go -> What is 3rd degree Heart Block?
         Go -> What is Sick Sinus Syndrome?
 
  Tachycardias
         Go -> What is sinus tachycardia?
         Go -> What are supraventricular premature beats?
         Go -> What is supraventricular tachycardia?
         Go -> What is atrial fibrillation?
         Go -> What are ventricular premature contractions?
         Go -> When should I begin therapy for premature ventricular contractions?
         Go -> What is ventricular tachycardia?
         Go -> Outline criteria to assist in the differentiation of supraventricular and ventricular premature beats.
 
  Miscellaneous
         Go -> What are the electrocardiographic signs of hyperkalemia?
         Go -> What are the electrocardiographic signs of myocardial hypoxemia/ischemia?
         Go -> What is the significance of low amplitude QRS complexes in the dog?
         Go -> What is the significance of wide QRS complexes?
         Go -> What is aberrancy?
         Go -> Differentials for Abnormalities on the ECG
 

Echocardiography
  Indications in Small Animals
         Go -> What is Two-dimensional Echocardiography?
         Go -> What other disorders can be detected with Doppler Echocardiography?
         Go -> What is M-mode Echocardiography?
         Go -> How does Doppler Echocardiography shed light on the presence of diastolic disease of the ventricle?
         Go -> What is Echocardiography?
         Go -> How does Doppler Echocardiography detect semilunar valve stenosis?
         Go -> How does Doppler Echocardiography detect atrio-ventricular valve stenosis?
         Go -> How does Doppler Echocardiography detect semilunar valve insufficiency?
         Go -> How does Doppler Echocardiogrpahy detect atrio-ventricular valvular insufficiency?
         Go -> Can Doppler Echocardiography provide insight into the severity of valvular heart disease?
         Go -> How is the Doppler Echocardiographic examination different from the routine echocardiographic examination?
         Go -> How does Doppler Echocardiography assist with the identification of cardiac disease?
         Go -> What are the Standard Transthoracic Echocardiography Views?
         Go -> What is Doppler Echocardiography?
         Go -> Is Echocardiography an invasive procedure?
 
  Examples to Demonstrate Diagnostic Values
         Go -> Congenital Heart Disorders
         Go -> Acquired Disorders
 
  Normal M-Mode Parameters
         Go -> Normal M-Mode Echocardiographic Parameters