Term
| the chambers of the heart |
|
Definition
|
|
Term
| Describe the layers of the heart wall |
|
Definition
Outside layer – pericardium – made of two layers
- the outer fibrous pericardium – made of tough, fibrous connective tissue that protects the heart and loosely attaches it to the diaphragm
- inner serous pericardium – made of 2 layers
1. inner layer – visceral layer, also called the epicardium, closely adhered to the underlying muscle
2. outer layer – parietal – lies between the epicardium and the fibrous pericardium
Myocardium – the thickest layer of heart tissue, inside the sac formed by pericardium. Made of cardiac muscle
Endocardium – thin membranous lining between the myocardium and the chambers of the heart |
|
|
Term
| Name and locate the valves of the heart and know which chambers they communicate with. |
|
Definition
Tricuspid valve – R atrium into R ventricle
Pulmonary valve – R ventricle into pulmonary artery
Mitral valve – L atrium into L ventricle
Aortic valve – L ventricle into coronary arteries and aorta |
|
|
Term
| What are the purposes of the cardiovascular system? |
|
Definition
Keeps blood moving through the vascular system
- oxygen and nutrients needed by cells
- hormones that help regulate body fxns
- antibodies and inflammatory cells needed to protect the body
- removing waste products from the tissue |
|
|
Term
|
Definition
| The outer layer of the heart |
|
|
Term
| What chambers of the heart are at the apex? |
|
Definition
The apex of the heart points in a ventral and caudal direction, and the tip of the apex of the heart is also the tip of the left ventricle.
The R and L ventricle are at the apex |
|
|
Term
| What chambers of the heart are at the base of the heart? |
|
Definition
|
|
Term
| Understand the Cardiac Cycle |
|
Definition
| Each contraction and relaxation of the heart is called a cardiac cycle. 2 main parts, systole and diastole |
|
|
Term
| Define Systole and Diastole and know what occurs in these cycles |
|
Definition
The 2 main parts of the cardiac cycle
Systole – during systole, the heart muscle contracts and blood is ejected from the atria to the ventricles and then from the ventricles to the arteries
Diastole – during diastole the heart relaxes and refilled with blood to be ejected during the next systolic contraction |
|
|
Term
|
Definition
| A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body |
|
|
Term
|
Definition
| A blood vessel that carries blood that is low in oxygen content from the body back to the heart |
|
|
Term
|
Definition
| A tiny blood vessel that connects an arteriole (the smallest division of an artery) with a venule (the smallest division of a vein). |
|
|
Term
| What are the names and locations of veins commonly used for venipuncture in dogs and cats? |
|
Definition
- cephalic vein – thoracic limb, runs between elbow and carpus on the cranio-medial aspect of the forearm. Carries blood from the distal extremity to the jugular vein
- femoral vein – more commonly used in cats, in the pelvic limb, runs along the medial aspect of the hind limb between the groin and the tarsal joint (hock) and carries blood proximally to the iliac vein, which travels to the vena cava.
- Saphenous vein – more commonly used in dogs, runs along the lateral aspect of the hind limb from the cranial aspect of the leg just above the hock (tarsus) to the caudal aspect just below the knee (stifle). Carries blood to the femoral vein. |
|
|
Term
| An evaluation of the cardiovascular system is part of any thorough physical examination. The parameters to be checked include |
|
Definition
- Mucous membrane color
- Capillary refill time (CRT)
- Palpation of the femoral pulse
- Auscultation of the heart - rate and rhythm, murmurs |
|
|
Term
| Valves auscultated in Left Lateral Thorax |
|
Definition
P = Pulmonic Valve
A = Aortic Valve
M = Mitral Valve |
|
|
Term
| Valves auscultated in Right Lateral Thorax |
|
Definition
|
|
Term
| Describe the areas to auscult the heart in dogs and the corresponding valves |
|
Definition
On each side of the chest around the level of the costochondral junction (just behind the level of the elbow when the pt is standing. Move the chest piece around slightly to auscultate in the vicinity of each heart valve.
Left lateral thorax
- pulmonic valve
- aortic valve
- mitral valve
Right lateral thorax
- tricuspid valve |
|
|
Term
| Describe the areas to auscult the heart in cats and the corresponding valves |
|
Definition
Best to auscultate directly over the sternum first and move the chest piece gradually up the left side and back over to the right side.
Valve positions similar to dogs but in cats abnormal heart sounds are more commonly auscultated in the sternal area. |
|
|
Term
| A complete cardiac exam includes: |
|
Definition
- assessment of perfusion status
- HR
- heart rhythm
- heart sounds |
|
|
Term
| Respiratory sinus arrhythmia |
|
Definition
| dogs may normally have a sl variation in heart rhythm, such that the HR increases sl during inspiration and decreases sl during expiration. Sign of normal cardiac fxn |
|
|
Term
| List the events responsible for the heart sounds heard on auscultation. |
|
Definition
The heart sounds typically heard in a normal pt are:
S1 (the 1st heart sound) – created by closure of the mitral and tricuspid valves at the start of systole
S2 (the second heart sound) – created by closure of the aortic and pulmonic valves at the end of systole
Both heart sounds together result in the typical “lub-dub” sound of the normal heartbeat.
The presence of a 3rd heart sound is termed a gallop rhythm because the resulting heart rhythm sounds like a galloping horse. A galloping rhythm is not actually an abnormal rhythm in the sense of electrical activity but is caused by an extra heart sound termed either S3 or S4. S3 and S4 cannot be differentiated by auscultation. Rarely S2 may be split and sound like a 3rd heart sound - uncommon
S3 – usually associated with ventricular dilation, such as with dilated cardiomyopathy
S4 – usually associated with decreased ventricular compliance and hypertrophy, such as with hypertrophic cardiomyopathy. |
|
|
Term
|
Definition
| created by closure of the mitral and tricuspid valves at the start of systole |
|
|
Term
| S2 (the second heart sound) |
|
Definition
| created by closure of the aortic and pulmonic valves at the end of systole |
|
|
Term
|
Definition
| usually associated with ventricular dilation, such as with dilated cardiomyopathy |
|
|
Term
|
Definition
| usually associated with decreased ventricular compliance and hypertrophy, such as with hypertrophic cardiomyopathy |
|
|
Term
| What does the capillary refill time assess? |
|
Definition
|
|
Term
| What is the normal CRT? What are some causes of increased and decreased CRTs? |
|
Definition
1 – 2 sec Normal
> 2 sec Poor perfusion
< 1 sec Stress, septic shock |
|
|
Term
|
Definition
- Anemia
- Poor perfusion or vasoconstriction – Shock, heart failure, dehydration
- Blood loss |
|
|
Term
|
Definition
| - poor oxygenation – heart and lung disorders, pleural effusion, etc |
|
|
Term
|
Definition
- liver disorder
- hemolysis |
|
|
Term
| Petechiation / ecchymosis |
|
Definition
- coagulation factor disorders (anticoagulants, etc)
- Platelet disorders
- DIC (disseminated intravascular coagulation) |
|
|
Term
| Dry / tacky mucous membranes |
|
Definition
- dehydration
- excessive panting |
|
|
Term
|
Definition
- septic shock
- fever
- stress |
|
|
Term
|
Definition
| small, visible, pinpoint hemorrhage lesions less than 1 mm in diameter |
|
|
Term
|
Definition
| visible hemorrhage lesions 1 mm to 1 cm in diameter |
|
|
Term
|
Definition
| yellow discoloration of the skin and mm resulting from accumulation of excess bilirubin (as seen in certain liver conditions) or excessive breakdown of RBCs (as seen after internal hemorrhage or various hemolytic states |
|
|
Term
| List some of the clinical signs / physical exam findings and history that you may see with heart disease. |
|
Definition
(these include signs of both reduced cardiac output and elevated preload)
slow capillary refill time (> 2 sec)
• pale or cyanosed mucous membranes
• dry or tacky mucous membranes
• cool extremities or reduced rectal temperature
• jugular venous distention or positive hepato-jugular reflux test
dyspnea, cough, harsh lung sounds, wheezes, or crackles on auscultation
• thrill on precordial palpation
• cardiomegaly on precordial palpation
• hepatomegaly and/or splenomegaly
• abdominal effusion
• subcutaneous edema
• weak femoral arterial pulse
• pulse deficits with irregular cardiac rhythm
• muffled heart sounds, gallop rhythms, heart murmurs, or arrhythmias may be detected on cardiac auscultation |
|
|
Term
|
Definition
Def: Fainting
Causes: Reduced cerebral perfusion |
|
|
Term
Lethargy
(with heart disease) |
|
Definition
Def: Lack of energy
Causes:
Reduced cerebral perfusion |
|
|
Term
|
Definition
Def: Difficult or labored breathing
Causes: Due to pulmonary edema or pleural effusion. Cough may occur due to mitral valve insufficiency with left atrial enlargement and compression of the left main-stem bronchus; may occur in the absence of heart failure |
|
|
Term
|
Definition
Def: Inability to breathe except when standing or sitting upright
Causes: Due to pulmonary edema or pleural effusion |
|
|
Term
|
Definition
Def: The accumulation of fluid in the peritoneal cavity, causing abdominal swelling
Causes: Congestive right-sided failure - blood return from the body to the right ventricle is impeded resulting in congestion in the systemic circulation. |
|
|
Term
|
Definition
Def: Fluid buildup within the alveoli or interstitial spaces of the lung
Causes dyspnea
Causes: Congestive left -sided failure - blood return from the lungs to the left ventricle is impeded resulting in congestion within the pulmonary (lung) vessels. This leads to pulmonary edema (fluid accumulation within the lungs). |
|
|
Term
|
Definition
Def: Pleural effusion (fluid in the space surrounding the lungs) which can cause respiratory distress, exercise intolerance, increased respiratory rate, open mouth breathing, or coughing
Causes: Congestive right-sided failure - blood return from the body to the right ventricle is impeded resulting in congestion in the systemic circulation. |
|
|
Term
|
Definition
Def: As detected by simultaneous cardiac auscultation and pulse palpation, a condition where each audible heartbeat is not accompanied by a palpable pulse wave – the pulse rate is less than the heart rate
Causes: This occurs because a cardiac contraction or several contractions take place prematurely not allowing enough time for ventricular filling (preload). This results in heart beats that do not eject enough blood to generate a palpable pulse.
The presence of pulse deficits should alert the diagnostician to the occurrence of premature ectopic beats. These may be either supraventricular or ventricular in origin, only the ECG can distinguish these. |
|
|
Term
| Which heart sound is heard when the pulse is felt? |
|
Definition
| The heart sound you hear when you first feel the pulse is S1, and when the pulse disappears is S2. |
|
|
Term
| The goals of auscultation are: |
|
Definition
a. To determine the heart rate
_ Bradycardia, normal, or tachycardia
b. To determine if there is a rhythm disorder
_ To be distinguished from a respiratory arrhythmia
c. To rule out muffled or absent heart sounds
_ Occur due to insulation between sound source and stethoscope as in:
- Presence of fluid in the pericardial space – pericardial effusion
- Presence of fluid in the pleural space – pleural effusion
- Mass in the pleural space or pericardial space
Pleural tumors
Pericardial tumors
Diaphragmatic hernia either to the pleural or pericardial space
Lung parenchymal disease
Obesity
_ May be a normal variant in some dogs
Other than for detecting asystole, auscultation cannot provide definitive evidence of heart failure. Rarely, individuals may have heart failure in the face of normal heart sounds and cardiac rhythm. The finding of gallop sounds is often very strong evidence of severe myocardial dysfunction. The presence of a murmur does not equate with heart failure. In fact, most patients with a heart murmur do not have heart failure. |
|
|
Term
|
Definition
Def: The vibration accompanying a cardiac or vascular murmur, detectible on palpation.
diastolic thrill one felt over the precordium during ventricular diastole in advanced aortic insufficiency
presystolic thrill one felt just before the systole over the apex of the heart
systolic thrill one felt over the precordium during systole in aortic stenosis, pulmonary stenosis, and ventricular septal defect.
Causes: a cardiac or vascular murmur |
|
|
Term
|
Definition
Def: occur between S1 and S2 (systole).
Causes: Systolic Murmurs
• Mitral and tricuspid valve endocardiosis
• Cardiomyopathy
• Physiologic flow murmurs
• Anemia
• Mitral and tricuspid valve dysplasia
• Atrial septal defect
• Ventricular septal defect
• Pulmonic stenosis
• Aortic stenosis
• Tetralogy of Fallot
• Mitral and tricuspid valve endocarditis
• Hyperthyroidism
• Heartworm disease
• Continuous or to-and-fro murmurs
• Patent ductus arteriosus
• Ventricular septal defect with aortic regurgitation
• Aortic stenosis with aortic regurgitation |
|
|
Term
|
Definition
Def: occur between S2 and S1 (diastole).
Causes: Diastolic Murmurs
• Mitral and tricuspid valve stenosis
• Aortic and pulmonic valve endocarditis |
|
|
Term
| What are the diagnostic aids used to evaluate the heart? |
|
Definition
palpation
• auscultation
• thoracic radiography
• electrocardiography
• blood work
• echocardiography
• other invasive, sophisticated tests |
|
|
Term
| hepato-jugular reflux (HJR) response |
|
Definition
This test checks for the presence of jugular distention or jugular pulsations when pressure is placed in the region of the cranial abdomen in a ventral to dorsal direction. The animal should be standing or in sternal recumbency to perform this test.
A positive test result indicates that there is elevated pressure in the right atrium or right ventricle. If one were to classify an elevated pressure in the right heart as mild, moderate or severe; venous distention indicates a severe elevation in pressure, a positive HJR indicates a moderate elevation in pressure. Patients with a mild elevation in pressure to the right heart cannot be identified on physical examination. |
|
|
Term
| What are some important technical aspects about stethoscopes and auscultation? |
|
Definition
1. Most of the disorders that promote abnormal heart sounds produce sounds that do not fall into the audible range. Thus, to detect those few that do fall into the audible range, careful auscultation is necessary to locate these sounds.
2. For the best sound reproduction, consider the following:
A double lumen scope is better than a single lumen
Shorter tubing is better than longer tubing
The best results occur if the room is quiet and one person is dedicated to controlling the head of the patient including closing the mouth to reduce panting. An attempt should be made to promote ease of breathing and reduce anxiety on the part of the patient.
The diaphragm is better for high frequency sounds such as most systolic murmurs, clicks, and breath sounds
The bell is better for low frequency sounds such as diastolic murmurs, and gallop sounds. If the bell is pressed tightly to the skin, the skin will function like a diaphragm and so the utility of using a bell will be lost.
3. Only auscult a patient when in the standing or sitting position. Auscultation of the patient in lateral or dorsal recumbency can result in creating false murmur like sounds (perhaps rubbing sounds) and/or impairs our ability to localize the PMI for a “real” murmur. |
|
|
Term
|
Definition
Heart murmurs are abnormal, extra sounds that are of a relatively long duration.
Heart murmurs occur as a result of turbulence within the heart created by disturbed blood flow.
Reynold’s number defines the variables that promote disturbed (non laminar) flow in a vessel or chamber. When Reynolds Number exceeds a critical value flow becomes turbulent.
Reynolds No = (Area)(Velocity)(Density) / Viscosity
Area = cross-sectional area of the chamber, orifice, or vessel; Velocity = velocity of blood flow (note that this is related to the area); Density = density of blood; Viscosity = viscosity of blood (affected mainly by the red blood cell count and protein count)
Blood flow turbulence can be created by high-velocity flow, flow from a narrow region into a larger area, or low blood viscosity. |
|
|
Term
| What causes heart murmurs? |
|
Definition
2. Causes of turbulance:
• Valvular insufficiency
• Valvular stenosis
• Connections between the cardiac chambers (i.e. interatrial and interventricular defects (holes)
• Connections between the great vessels (i.e PDA)
1. Associated with organic disease
1. Not associated with organic disease
• May be innocent / physiologic associated with low blood viscosity (anemia, hypoproteinemia)
• < grade 3
• occur in early to mid systole
• Note that if blood viscosity is increased, a murmur may be masked
• May be observed in young adults likely associated with ejection of blood into the great vessels
• < grade 3
• occur in early to mid systole
• Associated with increase in blood flow across a normal valvular orifice as with flow across the pulmonic valve in a VSD and ASD or across the aortic valve in bradycardia such as 3rd degree AV block
Anything that muffles the heart sounds can obscure a murmur such as obesity, thoracic effusions, or loud respiratory sounds |
|
|
Term
4. What are some of the causes of heart murmurs?
Cardiac related |
|
Definition
Causes of turbulance:
• Valvular insufficiency
• Valvular stenosis
• Connections between the cardiac chambers (i.e. interatrial and interventricular defects (holes)
• Connections between the great vessels (i.e PDA)
1. Associated with organic disease
1. Not associated with organic disease
• May be innocent / physiologic associated with low blood viscosity (anemia, hypoproteinemia)
• < grade 3
• occur in early to mid systole
• Note that if blood viscosity is increased, a murmur may be masked
• May be observed in young adults likely associated with ejection of blood into the great vessels
• < grade 3
• occur in early to mid systole
• Associated with increase in blood flow across a normal valvular orifice as Associated with increase in blood flow across a normal valvular orifice as with flow across the pulmonic valve in a VSD and ASD or across the aortic valve in bradycardia such as 3rd degree AV block
Anything that muffles the heart sounds can obscure a murmur such as obesity, thoracic effusions, or loud respiratory sounds. |
|
|
Term
| Grading Scale for Murmurs |
|
Definition
Grading Scale for Murmurs
• Grade I—barely audible
• Grade II—soft, but easily auscultated
• Grade III—intermediate loudness; most hemodynamically important murmurs are at least grade III.
• Grade IV—loud with palpable thrill
• Grade V—very loud, audible with stethoscope barely touching the chest; palpable thrill
• Grade VI—very loud, audible without the stethoscope touching the chest; palpable thrill |
|
|
Term
| What clinical signs may be seen with right-side heart failure? |
|
Definition
Congestive right-sided failure - blood return from the body to the right ventricle is impeded resulting in congestion in the systemic circulation. This systemic congestion can manifest as:
abdomen seen as abdominal distension) |
|
|
Term
| What signs may be seen with left-side heart failure? |
|
Definition
| Congestive left -sided failure - blood return from the lungs to the left ventricle is impeded resulting in congestion within the pulmonary (lung) vessels. This leads to pulmonary edema (fluid accumulation within the lungs). Common clinical signs observed include: |
|
|
