Exam 4 Flashcards
What are the common types of heart disease
Valve disease, aneurysm, coronary artery disease, cardiac arrhythmia, heart failure, cardiomyopathy, and pericarditis
What is the position of the heart in the mediastinum
Base shifted to the right and apex shifted to the left
What are the 2 parts of the pericardium
The fibrous pericardium and serous pericardium
What is the pericardial space
Potential space w/in the pericardium
What is the fibrous pericardium
The fibrous sac that loosely contains the heart but does not stretch
What are the layers of the heart wall from deep to superficial
Endocardium, myocardium, and epicardium
What is epicardium the same as
The visceral pericardium
What is attached to the endocardium
The papillary muscles
What is the purpose of papillary muscles
To prevent the valves from opening the wrong way
What is cardiomyopathies
Diseases of the myocardium
What is the primary heart disease in cats
Hypertrophic cardiomyopathy which can be seen via echo
What is the function of cardiac valves
Control blood flow by preventing back flow
What are the chordae tendinae
Tendon that holds valves to papillary muscle
Where does the deoxygenated blood from the myocardial capillaries go to reenter the heart for oxygenation
The coronary sinus that empties into the RA
What does the coronary arteries branch off of
The aorta
What does the AV node give the heart time to do
To fill up w/ blood
What does the AV node send the electrical signal to
Bundle of His that then transmits the signal into the separate left and right bundle branches
What are Purkinje fibers
Extensions of the left and right bundles sharing the electrical current to individual cardiomyocytes
What is the purpose of the Bundle of His and Purkinje fibers sending electrical signals at the same time
For the ventricles to depolarize at the same time
Where do nerve fibers enter the heart
In the right atrium to modulate automaticity
What ions are concentrated outside the cardiac myocyte while at rest
Ca+2 and Na+
What ion is concentrated inside the cardiac myocyte at rest
K+
What does one cardiac cycle equal
2 sounds a lub (S1) and dub (S2)
What is the lub sound
Occurs after atrial systole which is the tricuspid and mitral valves snap shut at the beginning of ventricular systole
What is the dub sound
Occurs after ventricular systole which is the pulmonary and aortic valves snap shut at the beginning of ventricular diastole
When can S3 and S4 be heard in the heart beat
In large animals you can hear the ventricular filling (S3) and the contraction of the atria (S4)
What are murmurs
Extra sounds heard when the paired AV valves or semilunar valves are not closing simultaneously
What are the common reasons for heart murmurs
Valvular insufficiency (incomplete closure), valvular stenosis (incomplete opening), and endocarditis
How many grades of heart murmurs are there
6 grades 1 being quietest and 6 being the loudest
What are the 2 most common grades of murmurs
3 & 4
What are the 3 other names for mitral valve disease and why are the other names appropriate
These are also accurate because it can be present in all valves; endocardiosis, degenerative valve disease, and myxomatous valvular degeneration
What is endocarditis
Infection and inflammation of the endocardium these patients come in w/ a new murmur and a high fever this can be caused by advance periodontal disease
Where do HW typically reside and what secondary diseases can it lead to
They originate in the pulmonary artery and when high numbers are present they can be seen in the right atrium and ventricle because of this they can lead to right sided heart failure, heart enlargement, and a tricuspid valve murmur
What imaging can show HW issues
An echo and changes to the heart can be seen on an xray
Why are heart diseases different from congestive heart failure
Congestive heart failure is the hearts pumping ability is decreased this can be right sided, left sided, or both and is seen differently clinically btw cats and dogs
What clinical symptoms do dogs in right sided heart failure present with
Coughing, lethargy, fainting episodes, ascites, pitting edema, and enlarged liver
What clinical symptoms do dogs in left sided heart failure present with
Crackling auscultations of the heart, pulmonary edema, coughing, and dyspnea
What clinical symptoms do cats in left sided or both sided heart failure present with
Pleura effusion and dyspena
What is stage A of canine heart disease
A dog is at risk for heart disease
What is stage B1 of canine heart disease
Signs of heart disease and is asymptomatic such as a murmur being present but no structural changes
What is stage B2 of canine heart disease
Signs of heart disease and asymptomatic such as murmur being present w/ structural changes
What is stage C of canine heart failure
Congestive heart failure is present or has been present and the dog is receiving treatment
What is stage D of canine heart disease
Congestive heart failure is present and refractory to standard therapies the patient also requires hospitalization as it is currently dying
What is cardiomegaly
Enlargement of the heart that is based of the vertebral heart score
What is the vertebral heart score
Measuring the distance from the top of the heart to the apex and across the base normal for most dogs is 9-11
What is treatment of congestive heart failure aimed at
Increasing strength of contraction, reducing vascular resistance in peripheral vessels, and reducing excessive fluid
What is the formula for cardiac output
CO = SV * HR
What is cardiac output
Blood pumped by LV/min
What is the stroke volume
Strength of the heartbeat that is affected by the preload, afterload, and length of cardiac myocytes it is over the amount of blood that is pushed out w/ every beat
What is preload
How much blood is in the ventricle before contraction
What is afterload
What is left in the ventricle based on the resistance of the left ventricle must overcome to circulate blood
What do larger animals have to make up for their slower HRs
A higher SV
What are elastic arteries and where are they found
They are found closest to the heart such as the aorta and they are able to stretch w/ incoming blood flow
What are muscular arteries and where are they located
The are found away from the heart such as arterioles and they are comprised of smooth muscle that is important for maintaining BP based on the ANS w/ constriction and dilation to direct blood to specific organs/tissues
What leaves circulation due to the thin walls of the venules
WBCs
Why do veins have valves
Because they are working against gravity to return the blood to the heart
What is the only vein that is safe to use w/ horses
The jugular vein
What veins are safe to use in cows
The jugular and coccygeal veins
What veins are safe to use w/ cats
Jugular, cephalic, and femoral
What is used for cardiovascular monitoring
Pulse, auscultation, arterial BP, thoracic radiographs, ECG, and echo
What is a pulse
Wave of stretching and recoiling of elastic fibers moves through arteries and arterioles allows for evaluating regularity and strength this should be the same as HB
What is pulse rate
Number of stretches/recoils palpated per min this should be the same as the HR
What is blood pressure
Pressure that flowing blood exerts on arterial walls it is not constant and is influenced by cardiac output, blood volume, diameter/elasticity of the artery
What is the formula for BP
BP = CO * SVR
What is the higher number in BP
Systolic BP
What is the lower number in BP
Diastolic BP
What is the mean arterial pressure (MAP)
Average pressure during one cardiac cycle used during anesthesia to monitor tissue perfusion
What is oscillometric method
Cuff placed over artery and cuff measures magnitude and frequency of pulsations
What is doppler ultrasound
Cuff attached to sphygmomanometer and transducer placed over artery distal to cuff
What does thoracic radiographs allow us to evaluate
The size, shape, and position of the cardiac silhouette
What is an echo and what does it show us
A cardiac ultrasound showing size, shape, movement of heart and its parts such as valves, calculate pressure in chambers, thickness of muscle, and assess for pericardial effusion
What is an ECG and what does it tell us
An electrocardiograph produces a graph that shows HR, normal rhythms, and arrhythmia
What are normal rhythms
Normal sinus rhythm and sinus arrhythmia in dogs
How is an electrocardiogram different from an ECG
The electrocardiogram produces a picture
What is the P wave
Depolarization of the atria
What is the QRS complex
Depolarization of ventricles
What is the T wave
Repolarization of ventricles
What delivers deoxygenated blood from the placenta
The umbilical arteries
How is oxygenated blood delivered to the fetus
The umbilical vein entering the fetus’ liver then caudal vena cava
How does the fetal heart bypass blood from being pumped into the lungs
The foramen ovale and the ductus arteriosus
What is the foramen ovale
Hole in the right atrium to send blood to the left atrium
What is the ductus arteriosus
Connection from the aorta and the pulmonary artery sending a small amount of blood to the lungs
When should the fetal heart’s bypass methods close
W/in the first couple of days after birth
What is patent ductus arteriosus
A non closure of the ductus arteriosus these are relatively common in young animals, produce a load washing machine sounding heart murmur that can be heard across the chest, and will lead to heart failure if untreated
What are common congenital cardiovascular diseases
Vascular ring abnormalies, patent ductus arteriosus (PDA), atrial septal defect (ASD), ventricular septal defect (VSD), pumonic stenosis (PS), subaortic stenosis (SAS), mitral valve dysplasia (MVD), tricuspid valve dysplasia (TVD), and tetraolgy of fallot
When are we super concerned about a puppy murmur
If it sounds like a washing machine or if it is still present by 6 months of age
What is a persistent right aortic arch (PRAA)
Vasculature forms a ring around the esophagus typically during fetal development when there are 2 aortic arches both of which remain present when it is suppose to disappear
What is traumatic reticuloperitonitis
Hardware disease that can cause pericarditis and pleuitis if the hardware break through the wall of the reticulum clinically these cows can show decreased consumption, mentation, reluctant to lay down or move, arched back, and show signs of an infection
What is used to treat traumatic reticuloperitonitis
Magnets are ingested by the cow to collect any hardware that makes its way into the stomach
What cat breeds are predisposed of HCM
Maine coon, sphynx, and british shorthair
What is hypertrophy
Increased cell size
What are diagnostics that can show HCM
NT pro BNP, thoracic radiographs when there is advance disease present, and echo at any stage of disease
What is aortic thromboemolism
Aka feline aortic thromboembolism and saddle thrombus is a clot that dislodged from the atria and travels down the aorta this must be treated immediately symptoms include down, vocalizing, super painful, and cold/cyanotic
How can HCM be treated w/ in certain cases
Pimobendan and clopidogrel
What does pimobendan do
It is a positive inotrope increasing contractility and a vasodilator
What does clopidogrel do
Inhibits platelet aggregation
What is the genus and species name for HWs
Dirofilaria immitis
What is the medical name for an HW overload
Cable syndrome
What are the steps for treating HWs in dogs
Killing Wolbachia an endosymbiont that make it easier for HWs to live this is done w/ doxycycline, killing dirofilaria immitis w/ an immiticide, and reducing associated inflammation
Why is important for dogs to be on cage rest while their HWs were being killed
To avoid HW embolism
How do you treat HWs in cats
Just let it ride it out while trying to regulate the immune response
What is the most common heart disease in dogs
Endocardiosis
When should medication for endocardiosis be started
Once we see heart enlargement
What are follow up diagnostics for endocardiosis
Thoracic radiographs, BP, ECG, echo
What are clinical signs of endocardiosis
Fainting episodes and excerise intolerance
What is used for endocardiosis treatment
Pimobendan to increase strength of contraction and dilates peripheral blood cells
What breeds of dogs are predisoposed for DCM
Doberman pinschers, boxers, great danes
What can cause DCM in cats
Taurine deficiency
What is the commen meds to use to treat DCM
Pimobendon, furosemide (diuretic), Enalapril (ACE inhibitors), Digoxin (cardiac glycosides), theophyline (bronchodilators), and anti arrhythmic drugs like beta blockers and Ca channels blockers
What is CHF
Inability to pump blood
What types of fluid accumulation occur when a patient is in CHF
pleural effusion, pulmonary edema, ascites, and pitting edema
What does arterial baroreflex trigger
Sympathetic
What do non stable CHF patients need
Furosemide, oxygen, nitroglycerin
What type of CHF patients always need to be hospitalized
Left sided heart failure
What does decreasing BP do for CHF patients
Decreases afterload decreasing the overall workload of the heart
What is nitroglycerin
Emergency treatment of CHF and is a venodilator ointment reducing preload by reducing venous return
