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217 Cards in this Set
- Front
- Back
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What is the definition of heart disease?
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Any structural or functional cardiac abnormality
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TRUE/FALSE: Heart disease, as it is clinically defined, always has a presenting clinical complaint.
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FALSE. Heart disease may present with obvious clinical signs or may remain subclinical/asymptomatic
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When performing a physical exam, what influences can age have on your assessment of the patient?
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A young patient with clinical signs related to heart disease is more likely to suffer from a congenital abnormality.
An older patient with clinical signs related to heart disease is more likely to suffer from a degenerative disease. |
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What other inherent patient factors have an effect on your assessment during physical exam/history?
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Breed
Sex Species |
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What other general disease process must you differentiate between when assessing cardiac disease?
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Respiratory tract disease. Many of the clinical signs that result from heart disease/failure can also result from respiratory disease.
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Would you expect a dog or a cat to present with cough associated with heart disease?
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Dog. Coughing is a RARE clinical signs associated with heart disease in cats.
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When inquiring about respiratory distress in cardiac patients, what do you expect the temporal sequence to be?
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Sudden onset of respiratory distress.
(Fluid in the lungs makes them stiffer and more difficult to expand) |
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What clinical signs has a hallmark of Transient loss of consciousness?
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Syncope
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When performing a physical examination, what general points of inspection should you cover?
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Body condition
Respiratory rate/character Demeanor |
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What effects on temperature might you expect in a cardiac patient?
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Severely affected patients with significantly decreased Cardiac Output will be hypothermic. Other types of cardiac disease might cause hyperthermia
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What is the normal pulse rate in dog? What are some of the normal variants you may expect?
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Normal rate = 70-160 bpm
Normal dogs can have a sinus arrhythmia - a change in heart rate associated with respiration. |
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What is the normal pulse rate of a cat? Would you expect to hear a sinus arrhythmia in a normal cat?
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Normal rate = 120-200. In clinic = 160-240
No, sinus arrhythmia in cats is VERY RARE in normal cats. It is controlled by vagal tone, and cats are anything but under the influence of vagal tone. |
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What is the normal heart rate for a horse?
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20-40 bpm
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What is the normal heart rate for cattle? What primarily influences the heart rate in cattle?
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Normal rate = 60-110 bpm
Control of heart rate is largely autonomic, with a higher concentration of sympathetic control than parasympathetic. Circulating catecholamines also influence heart rate. |
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What relationship is there between body mass and heart rate?
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Increase mass, decrease heart rate
Decrease mass, increase heart rate |
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Where are common areas to assess the arterial pulse in Small Animals?
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Femoral artery!!!
Dorsal pedal artery, brachial artery, conccygeal artery, digital artery, facial artery |
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What technique is commonly used to assess the femoral pulse?
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Feel with fingers along the Cranial edge of the femur
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What 2 important characteristics should be considered when assessing arterial pulse?
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Amplitude = strength of pulse
Quality = a subjective assessment of whether pulse rises and falls quickly or slowly. |
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The amplitude of the arterial pulse corresponds how to diastole & systole?
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The pulse amplitude is equal to the DIFFERENCE between the Systolic and Diastolic pressures
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Pulse pressure depends on what factors?
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STROKE VOLUME & velocity of ejection
Aortic distensibility Resistance to flow - rate at which blood leaves arterioles End-diastolic volume of arteries Heart rate |
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What effect on arterial pulse would you expect a small stroke volume (associated with hypovolemia and/or heart disease) to have?
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Weak/Hypokinetic pulse
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What is the most common cause for an absent arterial pulse?
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Thromboembolism
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What factors may contribute to a Bounding/Hyperkinetic arterial pulse?
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Anemia
Hyperthyroidism Aortic Valve Insufficiency PDA ***THINK WHY*** In most of these diseases, there is a significant increase in systolic pressure due to an increase in systolic volume being ejected. This artifically lowers the diastolic pressure, making the difference between systole & diastole more noticeable. |
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What is parvus et tardus and how does it relate to arterial pulse?
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Parvus et tardus = slow contour of arterial pulse rate associated with (sub) aortic stenosis
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What is the primary manometer for Central Venous Pulse? How is this assessed?
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The jugular vein!
Degree of distention HEIGHT of distention |
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Central venous pulse reflects what cardiac pressure?
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Right atrial & right ventricular diastolic pressure
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What is the pathophysiology associated with an extended central venous pressure?
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During atrial contractions (systole), central venous pressure decreases (as all the blood in the atrium is squeezed into the ventricle). During atrial filling (diastole), the pressure increases (all the blood from the venous system is flowing into the atrium). An extended central venous pressure correlates to an increased atrial pressure (during diastole) and right heart failure.
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How should your patient be positioned in order to assess central venous pressure?
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Patient should be standing
Hair may need to be clipped to better appreciate jugular distention. |
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TRUE/FALSE: CRT is not sensitive to acute decreases in Cardiac Output.
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TRUE! Since CRT is a measurement of the capillaries, it takes some time for cardiac insufficiency to travel down to the level of the capillary beds.
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What are th 2 primary differentials for mucus membrane pallor?
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Anemia
Vasoconstriction |
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What is difference between peripheral and central cyanosis?
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Peripheral cyanosis is caused by blood stasis in which all of the oxygen bound to Hb is absorbed into the tissues, making the blood look blue.
Central cyanosis is caused by respiratory insufficiency in which the blood being delivered to the tissues is already depleted in oxygen. |
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What are some common causes of peripheral cyanosis?
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Low cardiac output
Arterial obstruction |
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What are some common causes of central cyanosis?
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Lung disease
Rarely, Tetralogy of Fallot Pulmonic stenosis, ventricular outflow obstruction, aortic stenosis, ventricular hypertrophy |
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In healthy individuals, where is the PMI typically located?
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Left apex of heart (Apex Beat)
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Define a "thrill"
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Palpable vibration of the chest wall associated with a high intensity murmur
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Normal heart sounds, splits, clicks and gallops are all considered what type of heart sound?
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Transient
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What heart sounds are determinants of blood flow character?
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Murmurs
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What are the 4 cardiac cycle heart sounds associated with?
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S1 = AV valve closure
S2 = Semilunar valve closure S3 = Early diastolic filling (of ventricle) 24 = Atrial contraction |
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What is the characterization of sound frequency between s1, s2, s3, and s4?
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S3 and 4 have a lower frequency than S1 and 2.
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When does "splitting" of the heart sounds occur, in general?
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When 2 components of heart sounds S1 or 2 can be separately discerned.
i.e. The closure of the pulmonic and aortic valves or the mitral and tricuspid valves have enough of a time difference between them as to be heard separately. |
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Delay between the closure of the semilunar valves is associated with what disease processes?
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Outflow tract stenosis - i.e. Aortic or Pulmonic valve stenosis
Volume load Bundle branch blocks/Premature complexes (contractions) Physiologic delay associated with respiration |
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Delay between the closure of the AV valves is associated with what disease processes?
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Bundle branch blocks
Premature complexes (contractions) |
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Match the closure times:
Mitral >/< Tricuspid Aortic >/< Pulmonary |
Mitral > Tricuspid
Aortic > Pulmonary |
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What are high frequency, systolic sounds associated with mitral valve prolapse called?
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Clicks
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What signalment would you expect for a dog with audible clicks?
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Older, small-breed dog.
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Systolic clicks are a common precursor for what cardiac disease?
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Mitral valve regurgitation
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TRUE/FALSE: Audibility of the S3 and 4 heart sounds in horses and cattle is Normal.
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TRUE!
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In small animals, audibility of S3 and 4 are associated with what pathologic conditions in the heart?
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Atrial pressure are high
Ventricle is close to its elastic limit |
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When would S3 and 4 gallop sounds be "summated" in a cat?
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With high heart rates.
Can also occur in dogs |
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TRUE/FALSE: Due to stress and a corresponding elevated heart rate, it is common to hear gallop sounds in dogs & cats in a clinic setting.
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FALSE! Gallop sounds are almost never heard in healthy dogs & cats & are usually a specific marker for heart disease.
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How is a murmur clinically defined?
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Prolonged series of vibrations that originate from the cardiovascular system
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What change in the cardiovascular system is associated with the development of murmurs?
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Break down of laminar (smooth) blood flow into turbulent blood flow.
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What 2 primary factors influence blood flow characteristics?
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Velocity
Viscosity |
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Would acceleration or deceleration of blood flow be more likely to cause turbulent flow & subsequent murmurs?
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Acceleration of flow explains almost all murmurs
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What 3 characteristics are used to describe murmurs, for an inexperienced auscultator?
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Intensity/Loudness
Timing Location of PMI |
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Describe the general characteristics of a Grade 1 through Grade 6 murmur.
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Grade 1 = very soft & focal murmur
Grade 2 = soft murmur (that's immediately evident to an experienced auscultator) Grade 3 = A murmur of moderate intensity Grade 4 = A loud murmur with no thrill or an intermittent thrill Grade 5 = A loud murmur with as associated thrill Grade 6 = A loud murmur with a thrill that's audible with the stethescope just above the patient's chest |
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What 3 categories are there for classifying murmurs based on timing?
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Systolic
Diastolic Continuous |
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When can systolic murmurs be heard?
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Between S1 and S2
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When can diastolic murmurs be heard?
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Between S2 and S1
*Uncommon* |
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What is the TOP differential for a continuous murmur?
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PDA!
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Match the PMI to the anatomic correlate:
Left Heart Base Mitral Valve Right Heart Apex Aortic/Pulmonic areas Left Heart Apex Tricuspid Valve |
Left heart base = Aortic/pulmonic areas
Left heart apex = Mitral Valve Right heart apex = Tricuspid valve |
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Define Innocent Murmurs
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Murmurs that occur in the Absence of structural cardiac disease in animals that are otherwise normal.
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What signalment might you expect from a patient with an innocent murmur?
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Puppy
Kitten Sometimes adult horse |
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What type of murmur is often labile, changing its intensity based on changes in loading conditions & autonomic tone?
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Innocent Murmur
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What type of murmur occurs in "High Cardiac Output States"?
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Flow/Functional Murmurs
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What is the pathophysiology associated with Flow/Functional Murmurs?
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An increase in stroke volume without a change in the duration of systole causes an increase in ejection velocity.
An increase in velocity leads to an increase transition from laminar to turbulent flow, producing a murmur. |
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What conditions might cause a Functional/Flow murmur?
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Thyrotoxicosis
Fever Athleticism |
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TRUE/FALSE: The heart functions as two separate pumps that are connected in series so that over time, the cardiac output of the left and right heart are equal.
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TRUE!
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With respect to oxygen load and pressure, how is the systemic circulation different from the pulmonary circulation?
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Systemic circulation = High O2, high pressure
Pulmonary circulation = Low O2, low pressure |
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What are the anatomical features of the right ventricle that relate to its function?
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Pyramidal geometry (wraps around Left ventricle)
Septomarginal trabeculation Coarse trabeculae |
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What are the anatomical features of the left ventricle that relate to its function?
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Smooth wall
Fibrous continuity of aortic & mitral valves |
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The volume of blood the heart ejects each systole is equal to what?
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Stroke volume
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What is the measurement of cardiac output?
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The volume of blood pumped by the heart in 1 minute
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What are the 4 determinants of Cardiac Output?
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Heart Rate
Preload Afterload Contractility |
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What relationship does heart rate have with Cardiac Output?
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Heart rate, the number of cardiac cycles per minute, has a DIRECT relationship with Cardiac Output. So, an increase in Heart Rate will increase Cardiac Output.
**Until, the heart rate becomes too great as to impair ventricular contraction** |
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What is the preload?
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The force that stretches the myocardium prior to contraction
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How is the preload measured?
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Estimated by measuring end-diastolic volume or pressure
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What relationship do the preload and Cardiac Output have? What Law illustrates this relationship?
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Direct relationship --> Increase preload, increase Cardiac Output. Decrease Preload, Decrease Cardiac Output.
Described by Frank-Starling's Law of the Heart |
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What is the afterload?
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The forces that oppose ventricular ejection
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How is the afterload measured?
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Aortic pressure, related to peripheral vascular resistance.
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What is clinically significant about the afterload?
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It can be manipulated pharmacologically, as during treatment for cardiac disease.
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What relationship does afterload have with Cardiac Output?
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Indirect relationship --> Increase afterload, Decrease Cardiac Output. Decrease afterload, Increase Cardiac Output
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What is contractility?
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The inherent, load dependent, ability of the cardiac muscle to shorten (contract)
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What relationship does contractility have with Cardiac Output?
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Direct --> Increase contractility, Increase Cardiac Output. Decrease contractility, Decrease Cardiac Output
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How is heart failure generally defined?
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A syndrome of clinical signs that results from impaired emptying or filling of the heart.
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How are heart disease and heart failure related?
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Heart failure is a syndrome that can be CAUSED BY Heart disease. However, the terms are NOT synonymous. Unless the cause can be eliminated, heart failure is a terminal event.
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What is the primary clinical sign associated with Left Heart Failure?
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Pulmonary edema
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What is the primary clinical sign associated with Right heart failure?
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Ascites
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What are the 4 anatomic regions of the heart used to classify heart disease?
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Pericardium
Myocardium Endocardium/Valves Conduction System |
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What are the 6 Mechanisms of heart disease? Which are the most commonly seen in veterinary medicine?
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*Volume Overloads
*Contractile Dysfunction *Diastolic Dysfunction Pressure overloads arrhythmias high cardiac output states |
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What is echocardiography?
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The technique of producing images of the heart, the great vessels entering & leaving the heart and of blood moving within these chambers by means of reflected ultrasounds waves (echoes)
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How is an image of the heart produced from an ultrasound beam in echocardiography?
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Beam is directed through the chest wall & heart.
Beam strikes an interface between 2 structures with different acoustic impedances (aka densities) Part of the sound is reflected back towards the transducer to help make the image of the heart. |
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What disease processes are best evaluated using echocardiography?
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Evaluation of myocardial structure & function:
Pericardial effusion - presence AND cause! Tumors Thrombi/spontaneous echocontrast (smoke) Heartworms Left atrial enlargement (cats) |
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What are the factors that influence the effectiveness and accuracy of an Echo?
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Type of equipment
Modality of visualization Patient Operator skill |
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What are the 3 modalities used in an Echo?
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M-mode = Motion mode
2D Doppler (which includes multiple modalities itself) |
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What are some transducer frequencies recommended for a cat, a medium dog, and a large dog? What is the general trend in frequencies?
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Cat = 8-12 MHz
Medium Dog = 4-8 MHz Large Dog = 2-4 MHz General trend is to decrease frequency as patient size increases to achieve greater penetrability of the ultrasound beam. |
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Transesophageal imaging of the heart is an alternate technique in Echo. What are the advantages & disadvantages associated with this technique?
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Advantages = Not limited by obesity or lung interface
Aids in diminishing radiation exposure during cardiac catheterization procedures (such as in heartworm treatment, PDA surgery, etc.) Disadvantages = Requires general anesthesia Potential to cause esophageal lesions. |
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What are the 3 primary imaging planes/approaches in Echo?
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Right parasternal approach --> Long axis plane OR Short axis plane
Subcostal approach Left Apical approach |
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What heart structures are visible using a Right parasternal approach in the long axis plane?
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R/L Ventricles
R/L Atria Pulmonary outflow tract Aortic outflow tract |
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What heart structures are visible using a Right parasternal approach in the short axis plane?
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Right and Left ventricles, viewed in cross section
Valvular outflow tracts in cross section |
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Why is a subcostal approach primarily utilized?
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To measure velocity within the left ventricular outflow tract (aorta & associated valves)
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A left apical approach is synonymous to what radiographic view of the heart?
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DV or VD view.
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When viewing an M-mode Echo, what corresponds to the vertical axis & what corresponds to the horizontal axis?
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Vertical axis = movement of cardiac structures
Horizontal axis = time |
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TRUE/FALSE: M-mode Echo is not useful is assessing cardiac structure.
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FALSE: M-mode displays the depth of cardiac structures from the transducer displayed in cm. This give an indication of heart chamber size AND function.
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What important data does M-mode provide on the heart?
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Measurements of ventricular dimensions, left atrial & aortic root dimension, and ventricular wall thickness
Amplitude of motion of the ventricular wall Valvular anatomy, motion & timing of valve opening & closing Fractional shortening |
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What is fractional shortening?
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A measurement obtained by dividing the difference between the left ventricular end-diastolic dimension AND the left ventricular end-systolic dimension by the left ventricular end-systolic dimension. This fraction is converted to a percent, with normal values ranging from 28-40%.
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What 2 modalities are included in Doppler echocardiography?
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Color Doppler
Spectral Doppler |
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How does Doppler reflect velocity within the heart?
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The frequency shift in a sound wave reflected from a moving object has a mathematical relationship to the velocity of said object.
In Doppler Echo, sound is reflected from moving RBCs or the myocardium (tissue Doppler) and the resulting frequency shift is expressed in terms of velocity. |
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The angle of intercept between the emitted ultrasound pulse and the long axis of blood flow/myocardium should be closest to what angle?
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0 degrees.
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What is the BART convention in Color Doppler?
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Color is assigned to blood moving towards and away from the transducer, as displayed in a 2D image. Blue moves Away, Red moves Toward the transducer.
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How is Color Doppler typically used?
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Primarily as a screening tool as it provides little quantitative information.
It does allow the examiner to see shunted blood passing through a defect or areas of turbulent flow. |
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What 2 methods fall under Spectral Doppler?
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Continuous wave Doppler
Pulsed wave Doppler |
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Why is Continuous Wave Doppler performed?
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To measure High Velocity Blood Flow without much sensitivity to Exactly Where the flow is located.
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Why is Pulsed Wave Doppler performed?
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To permit the examiner to sample blood/myocardial velocity at a specific location in the heart. However, Very high velocities cannot be measured with Pulsed Wave Doppler due to aliasing of the signal.
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All cases of Congenital Heart Disease require an echocardiogram (with Doppler evaluation) in order to...
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Verify presence of lesion
Evaluate secondary lesions Detect additional or multiple cardiac defects Detect sites of left to right shunting in cyanotic patients Estimate the severity of disease Assessment of myocardial function |
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When would an Echo be indicated in a case of Dilated Cardiomyopathy?
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When the signalment is atypical
Radiographic findings are equivocal (ambiguous) |
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When would Echo be indicated in a case of Hypertrophic Cardiomyopathy?
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Hypertrophic Cardiomyopathy is a diagnosis of exclusion. Therefore, Echo can be used to diagnose HCM in cases of:
Diagnosis of Feline Myocardial Disease (FMD) To monitor for left atrial enlargement Thrombi within the cardiac chambers Pericardial effusion |
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Why would Echo be used in a case of Myocarditis?
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To reflect the extend of the myocardial damage
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Echo is useful in Dogs with Chronic Degenerative Valvular Disease if...
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Radiographic findings are equivocal
Pulmonary hypertension is suspected Assessment of myocardial function is important |
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Why is Echo useful in cases of Infective endocarditis?
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To evaluate vegetative lesions on the valves or endocardial surfaces
However, this is NOT a substitute for properly performed blood cultures |
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Echo is the most sensitive clinical technique for detecting what disease?
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Pericardial effusion
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If you wanted to utilize an effective & non-invasive technique to detect cardiac tumors, what would you use?
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Echocardiography!
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When can Echo detect pulmonary hypertension?
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When tricuspid or pulmonary valve regurgitation is present.
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What is the basic electrophysiology associated with cardiomyocytes?
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An electrochemical gradient is maintained across the cell membrane, making cardiomyocytes excitable.
Stimulation of these myocytes results in a momentary reversal of this trans-membrane electrical potential. This potential is known as the Action Potential. The Action Potential is the stimulus for myocardial shortening |
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What are the 2 electrophysiologically distinct groups of cells in the heart?
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Specialized conduction cells
Working cardiomyocytes |
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What are the unique characteristics of Specialized Conduction Cells?
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Depolarize spontaneously, allowing them to function as "pace-maker" cells
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What is the main pacemaker of the heart? Why? What path does the electric pace follow?
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SA node is the main pacemaker due to its highest inherent rate of depolarization.
Electrical signals follow through to the AV Node --> Bundle of His/Bundle Branches --> Purkinje fibers |
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What does an electrocardiogram measure?
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The Difference in electrical potential across cardiomyocytes
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How do the "leads" of an EKG reflect electrical activity of the heart?
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The different leads are merely different vantage points used to "view" the heart's electrical activity
When a wave of depolarization moves towards the electrodes of a lead, the machine measures a positive deflection. When a wave of depolarization moves away from the electrodes, it measures a negative deflection. |
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EKG is useful in evaluation of what 2 cardiac factors?
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Rate of depolarization/excitation of cardiomyocytes
Rhythm of depolarization/excitation |
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When is an EKG indicated as a diagnostic tool?
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When the heart rate is:
Too Fast Too Slow Inappropriately irregular |
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What is the standard position for an animal to be in when performing an EKG?
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Right lateral recumbency
Each lead corresponds to a particular limb based on this position. |
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What "directions" does a heart normally depolarize?
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Right to Left
Cranial to Caudal Dorsal to Ventral |
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The QRS wave in dogs & cats is typically what "direction"?
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Positive (toward Lead II)
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Match the electrical activity to the EKG structure:
Atrial Depolarization - T wave Ventricular Depolarization - P wave Ventricular Repolarization - QRS complex |
Atrial Depolarization = P wave
Ventricular Depolarization = QRS complex Ventricular Repolarization = T wave |
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TRUE/FALSE: All ventricular complexes have a T wave.
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TRUE! The T wave corresponds to ventricular repolarization, and the ventricles MUST repolarize BEFORE they depolarize.
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What 3 questions should you ask when approaching interpretation of an EKG?
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What is the heart rate?
What is the Rhythm? (Irregular or regular? Are the peak R intervals the same? Do they change abruptly?) What is the association between atrial & ventricular activity? |
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TRUE/FALSE: Most premature complexes disturb the underlying rhythm.
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TRUE
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TRUE/FALSE: Premature complexes often occur within the ST segment.
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FALSE: They CANNOT occur during the ST segment.
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What is the Mean Electrical Axis?
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The dominant direction of ventricular activation
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Arrhythmias refer to any deviation from the regular sinus rhythm. What 3 categories are they classified as?
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Physiologic or Pathologic
Tachyarrythmia Bradyarrhythmia |
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What conditions cause the development of an arrhythmia?
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Disease of the conduction system that prevents initiation or propagation of the wave front
Disease of the myocardium the causes spontaneous depolarization of working myocytes |
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In general, Tachyarrhythmias develops in association with what diseases?
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Structural cardiac diseases --> Diseased hearts typically get big. Big hearts need more oxygen. More oxygen provides greater fuel for contractions
Extra-cardiac disease: Electrolyte abnormalities Acid/Base disturbances Autonomic imbalance. |
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In general, bradyarrhythmias develop when?
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Disease of the conduction system slows the rate of depolarization or "blocks" conduction
Autonomic factors (high vagal tone) produce the same function effect as the disease state |
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What are the characteristics of sinus arrhythmias?
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Heart Rate Variability within physiologic limits
Dependent on vagal discharge Often accompanied by a wandering sinus pacemaker EKG has a P wave of normal morphology that precedes every QRS by a consistent & believable PR interval |
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What are the characteristics of a sinus tachycardia?
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Elevated heart rate...duh
EKG has a P wave of normal morphology that precedes every QRS by a consistent & believable PR interval. |
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What are the characteristics of a sinus bradycardia?
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Decreased heart rate...duh
EKG has a P wave of normal morphology preceding every QRS by a consistent and believable PR interval |
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What will the appearance of the QRS complex be in the case of a Supraventricular Tachyarrhythmia?
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QRS morphology is generally normal with a narrowed width.
Since arrhythmia is "supra"/above the ventricle, the QRS complex should not be affected. |
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What are the characteristics of supraventricular premature complexes?
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Occur early in EKG --> Abnormal rhythm superimposed over P wave
Have narrowed QRS Often associated with diseases that cause atrial distention |
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In Supraventricular TachyCARDIA, how is the EKG characterized?
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Usually presents as NORMAL rhythm
Start & stop abruptly QRS is narrow |
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When is Supraventricular TachyCardia categorized as pathologic?
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When there is an ABRUPT change in heart rate.
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What are the EKG signs of atrial fibrillation?
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Rapid heart rate
Irregular rhythm (no regularity in distance between R peaks) Monomorphic complexes with narrowed QRS and NO distinct pattern |
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When assessing an EKG for atrial activity, what structure should you focus on?
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P wave
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TRUE/FALSE: Atrial fibrillation is sometimes seen in horses and giant-breed dogs in the absence of structural heart disease.
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TRUE!
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What are the EKG signs associated with Ventricular Premature Complexes?
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Occur early in cardiac cycle
Are Wide and Bizzare *Positive vs negative wave direction depends on where complex originated* |
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What are the characteristics of Ventricular Tachyarrythmia?
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Rapid heart rate
Regular rhythm (Ventricular TachyCARDIA) Initiated by Ventricular Premature Complex Often associated with structural disease |
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What are the effects of Ventricular Tachycardia/arrhythmia on the physiology of the patient?
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Can cause signs of low cardiac output
Can degenerate into ventricular fibrillation = death Sometimes the prodrome (clinical precursor) of severe myocardial dysfunction. |
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What extracardiac diseases are associated with Ventricular Tachycardia/arrhythmia?
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Trauma
GDV (bloat) Splenic disease Neurologic Disease Sepsis |
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What is the etiology of extracardiac disease that leads to Ventricular Tachyarrhythmia?
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Autonomic factors (Neurologic disease)
Electrolye disturbances Acid/base disturbances |
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What are the EKG signs associated with Ventricular Tachyarrhythmia in Extracardiac disease?
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Slower (for tachycardia)
Initiated by LATE diastolic Ventricular complexes Electrically benign Resolve spontaneously --> Generally well tolerated by patient |
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What are the main etiologies associated with AV Block & corresponding Bradyarrhythmias?
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Functional change related to elevated vagal tone
AV node disease |
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Match the AV Block to its pathology:
1st Degree Block - Complete failure of AV conduction 2nd Degree Block - PR prolongation 3rd Degree Block - Intermittent failure of AV conduction |
1st Degree Block = PR prolongation
2nd Degree Block = Intermittent Failure of AV conduction 3rd Degree Block = Complete failure of AV conduction |
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What effects do High Grade 2nd degree/3rd degree AV Blocks have on the patient?
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Cause of syncope/exercise intolerance
Occasionally a cause of CHF/sudden death |
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What disease states are 2nd/3rd Degree AV Block Bradyarrhythmias associated with?
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Usually result from idiopathic fibrosis in dogs
Occasionally associated with myocardial disease, aortic valve endocarditis Important indication for cardiac pacing |
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Sick Sinus Syndrome is typically characterized by what cardiac features?
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Sinus pauses
Sinus bradycardia Sometime Supraventricular Tachyarrhytmia/cardia |
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Sick Sinus Syndrome most commonly manifests how & in what breeds?
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Manifests as syncopal episodes
Breeds: Older Miniature Schnauzers Dachshunds Terriers |
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Hyperkalemia-Associated Brachyarrhythmia is typically associated with what disease states?
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Urethral obstruction
Oliguric renal failure Addison's disease |
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What are the EKG signs of Hyperkalemic Bradyarrhythmia?
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Wide QRS
P-waves of low amplitude/absent P waves Peaked T waves |
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What is the primary modality of Ambulatory Electrocardiography in the diagnosis of Syncope?
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Holter monitoring/Event recording
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How are tachyarrythmias typically treated?
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Pharmacologically
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How are symptomatic bradyarrhythmias typically treated?
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Cardiac pacing
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Almost ALL forms of Congenital heart disease present with what cardiac pathology?
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Murmur!
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TRUE/FALSE: Findings of normal growth/lack of clinical signs at the time of detection of a congenital heart disease is indicative of a good prognosis.
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FALSE!
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Innocent murmurs are typically found in ______ and ______. They are ALWAYS _____ and ALWAYS _______.
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Kittens and Puppies
Soft and systolic |
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TRUE/FALSE: A loud murmur is always indicative of disease presence.
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TRUE!
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CHD is most appropriately treated with Mechanical Means. What are the primary means of treatment?
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Surgical approaches
Interventional catheterization (aka IR!) Medical therapy - palliative only |
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If a patient presents with only a PDA as their CHD and pulmonary vascular resistance decreases, the shunt is most likely in what direction?
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Left to right
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A left to right PDA imposes a volume load on what side of the heart?
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LEFT atrium
LEFT ventricle *Blood that the left heart thought it was sending out to the periphery is really just flowing back into itself after passing through the pulmonary vasculature again* |
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What are some potential consequences of a left to right PDA?
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Myocardial dysfunction
Mitral valve regurgitation Congestive Heart Failure |
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What is the most common signalment associated with PDA?
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Small breed
Female *Small, white, fluffy dog* |
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What physical findings are highly indicative of PDA?
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CONTINUOUS MURMUR
Bounding arterial pulse |
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What radiographic findings are indicative of PDA?
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Cardiomegaly due to Left heart enlargement
Pulmonary hyperperfusion & edema Dilation of Aorta & MPA |
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What Echo findings are indicative of PDA?
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Left Heart Enlargement
Mitral valve regurgitation Continuous disturbed flow with MPA - apparent with Doppler Ductus may be visible from left cranial parasternal images |
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What is the traditional approach to therapy for a PDA?
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Ligation following a left lateral thoracotomy
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More recently, what techniques have been used to treat PDAs?
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Transcatheter ductal occlusion
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Pulmonic stenosis is most often due to what pathologic processes?
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Dysplasia of pulmonic valve (Thickening of valves)
Abnormal attachment of leaflets to each other (without thickening) |
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What effect does Pulmonic Stenosis have on the heart?
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In order to maintain flow and pressure beyond the stenosis, the Right Ventricle must generate abnormally high systolic pressures & can eventually lead to Right heart failure
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What is a typical signalment & physical findings associated with Pulmonic Stenosis?
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Signalment = Terriers, Old English Bulldog
Physical Findings = Systolic murmur over Left Heart base (not right heart, because R heart wraps around L) |
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What modality of Echo is required for definitive diagnosis of Pulmonic Stenosis?
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Doppler - any modality within
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What are the main treatment techniques for Pulmonic Stenosis?
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Interventional Catheterization = Balloon valvuloplasty
Surgery = Patch graft or definitive repair |
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What clinical signs might you expect from Pulmonic Stenosis?
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Coughing/exercise intolerance
ASCITES - associated with right heart disease |
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What anatomic structure predisposes SUBvalvular aortic stenosis moreso than valvular or supravalvular?
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Subvalvular fibrous ring
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What is the pathophysiology of SAS?
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In order to maintain normal systemic pressure and flow, the Left Ventricle my generate abnormally high systolic pressures
A pressure gradient develops across the obstruction SAS imposes a pressure load on the Left ventricle |
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What diagnostic technique can be used to estimate/directly measure the pressure gradient associated with SAS?
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Doppler Echo.
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What is a typical signalment for a patient with SAS?
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Large breed dog
Inherited in Newfoundlands High Risk in Golden Retrievers, Rottweilers, Boxers |
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What physical findings are typical for a patient with SAS?
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Systolic murmur over Left Heart Base
Weak/hypokinetic arterial pulse |
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What imaging findings are typical in a patient with SAS?
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Radiographs = +/- Heart enlargement
Echo = Doppler required for definitive diagnosis |
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What are the principles of therapy associated with SAS?
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Definitive surgical correction requires cardiopulmonary bypass
Surgical gradient reduction may not affect survival Balloon dilation may be palliative Beta-blockade (using Atenolol) may help in decreasing heart rate & myocardial oxygen demand |
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TRUE/FALSE: Patients with SAS suffer from a broad spectrum of severity of disease with sudden cardiac death is a potential risk.
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TRUE
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What is a Ventricular Septal Defect?
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Deficiency/hole in the Interventricular Septum, usually in the peri/membranous region
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What is the pathophysiology associated with VSD?
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An isolated VSD causes a left to right shunt and imposes a volume load on the LEFT heart
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What is a common signalment for VSD?
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Cats
Bloodhounds English Bulldogs Shiba Inu |
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What physical findings are common in VSD's?
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Systolic murmur, typically associated with a Right Apical thrill
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Although most VSD's in small animals are small & do not require correction, what are some modes of treatment for VSD's?
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Surgery under bypass
Medical Therapy with ACE inhibitors, Furosemide, Digoxin & Pimobendan |
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Prognosis of a patient with a VSD depends on what factors?
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Defect size
Presence of concurrent lesions (Aortic valve insufficiency, R ventricular outflow tract obstruction, etc.) |
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What are the pathologic effects of an Atrial Septal Defect?
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A left to right ASD imposes a volume load on the RIGHT heart
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A murmur derived from "functional PS" is typically associated with what congenital heart disease?
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Atrial Septal Defect
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Though ASD is relatively uncommon, what are some treatment modalities for it?
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Interventional catheterization
Surgery under cardiopulmonary bypass |
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Dysplasia of the AV valves usually results in what disease processes?
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Valve regurgitation
Stenosis |
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What are the principle characteristics of AV Valve Dysplasia ?
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Relatively common in cats & labs
Severity is variable Correction requires surgery under cardiopulmonary bypass |
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Cyanotic Heart Disease is caused by what pathologic process(es)?
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Cardiac defects that result in Right to Left shunts & admixture of venous blood with arterial blood.
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What effects on the heart does Cyanotic Heart Disease have?
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Markedly elevated Right Artial/Ventricular pressures +/- Elevated Pulmonary artery pressure
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In order to produce Cyanotic Heart Disease, a shunt and what other pathology are required?
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Tricuspid stenosis OR
Severe pulmonic stenosis OR Pulmonary hypertension associated with elevated pulmonary vascular resistance |
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What clinical signs are associated with Cyanotic Heart Disease?
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Exercise intolerance
Complications arising from Polycythemia --> Kidneys function as in a state of hypoxia & increase EPO production, leading to erythrocytosis/polcythemia |
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What is the principle behind Eisenmenger's Physiology?
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Elevated pulmonary blood flow can result in vascular disease, a rise in pulmonary vascular resistance and shunt reversal.
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What disease processes make up the Tetralogy of Fallot?
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Pulmonic Stenosis
Ventricular Septal Defect Right Ventricular Hypertrophy Aortic malposition |
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How is Cyanotic Heart Disease derived from the Tetralogy of Fallot treated?
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Definitive repair requires surgery under cardiopulmonary bypass
A phlebotomy or medical management with a beta blockade may be palliative |
