Cardiovascular Disease Flashcards
what is the function of the heart?
to pump blood around the body (via the lungs and systemic circulation)
what is the normal HR of dogs?
60-180 bpm
what is the average heart rate of cats?
120-240 bpm
when are congenital cardiac diseases present?
from birth
in what age group of animals are congenital heart diseases most often seen?
young animals
what causes congenital heart diseases?
abnormalities of heart development in utero
what are 4 of the common congenital cardiac diseases?
aortic stenosis
pulmonic stenosis
patent ductus arteriosus
ventricular septal defect
what is occurring during aortic or pulmonic stenosis?
narrowing of valves
what is a patent ductus arteriosus?
failure of the closure of a foetal vessel
what is a ventricular septal defect?
hole in ventricular septum
when do acquired heart diseases develop?
later on in life
what are the most common heart diseases of the valves in dogs?
myxomatous mitral valve disease
what is the most common heart disease of the myocardium in dogs?
dilated cardiomyopathy
what is the most common heart disease of the pericardium in dogs?
pericardial effusion
what is the most common acquired heart disease in cats?
hypertrophic cardiomyopathy
what is the other type of cardiac disease apart from congential and acquired?
arrhythmias
what are the 2 main types of arrhythmia?
bradyarrhythmia and tachyarrhythmia
what tests/assessments form part of the diagnosis of heart disease?
full history physical exam blood tests blood pressure ECG Holter monitor Echocardiography thoracic radiographs
what is a Holter monitor used for?
24h ECG
what is involved in echocardiography?
cardiac ECG
how do patients with cardiac disease present?
incidental finding exercise intolerance weakness syncope heart failure sudden death
how may heart disease be found incidentally?
heart murmur or arrhythmia detected on vaccination
what are the main signs of left sided heart failure?
tachypnoea
dyspnoea
what are the main signs of right sided heart failure?
difficulty breathing and/or distended abdomen
what areas should be assessed on physical exam of a patient with suspected heart disease?
body condition mucous membranes jugular veins peripheral pulses RR heart auscultation
what may be found when assessing body condition of a patient with suspected heart disease?
cardiac cachexia
what is cardiac cachexia?
loss of lean muscle mass seen with severe heart disease
what are you assessing when looking at a patients mucous membranes?
colour and CRT - perfusion and oxygenation
what may be shown by looking at the jugular veins of a patient with potential heart disease?
pulsation
what are you assessing when looking at a patients peripheral pulses?
quality of pulse
is it regular
any deficits
what are pulse deficits?
HR present but peripheral pulse isn’t (may only be for the odd beat)
what is the normal RR for a sleeping/normal dog?
<30 brpm
what may the RR be of a dog with CHF?
> 35-40 brpm
when auscultating the heart what are you looking at?
HR
rhythm
assessment of pulses alongside
what can be assessed about HR rhythm?
regular or irregular
gallop sounds
what are gallop sounds?
abnormal extra heart sounds
what should be assessed simultaneously with HR auscultation?
pulse quality (weak/strong) pulse deficits
what are you listening for if a heart murmur has been detected?
timing (at systole or distole)
point of maximal intensity
what valve murmurs have their point of maximal intensity on the left side of the patient?
pulmonary
aortic
mitral
what valve murmurs have their point of maximal intensity on the right side of the patient?
tricuspid
what are the grades of heart murmur?
1-6
describe a grade 1 heart murmur
very quiet, takes time to localise
describe a grade 2 heart murmur
quiet, less loud than heart sounds
describe a grade 3 heart murmur
obvious, as loud as heart sounds
describe a grade 4 heart murmur
louder than heart sounds
describe a grade 5 heart murmur
very loud with precordial thrill
describe a grade 6 heart murmur
very loud, thrill, audible even when lifting stethoscope off chest
what is precordial thrill?
feel murmur against hand if placed on chest
what should be assessed when auscultating the lungs?
RR
adventitious sounds (anything other than breathing)
crackles
what are the typical findings in a patient with heart failure?
reduced cardiac output weakness exercise intolerance syncope heart murmur gallop sounds arrhythmias
what are the signs of reduced cardiac output?
weak peripheral pulses tachycardia pale MM prolongued CRT congestion usually short history of clinical signs
what is congestion due to?
blood is not pumped forwards rapidly enough so pressure in the respective atria increases and blood backs up into vessels of the lungs or systemic circulation
what are the signs of left sided (lung) congestion?
pulmonary oedema
tachypnoea
dyspnoea
cough
what are the signs of right sided (systemic) congestion?
distended peripheral veins
ascites
pleural effusion
what is ascites?
fluid build up in abdomen
what types of blood test are used to assess cardiac function?
haematology
biochemistry
cardiac biomarkers
what does haematology asses with regards to cardiac function?
systemic diseases
anaemia (haemic murmur)
what is a haemic murmur?
heart murmur caused by the change in blood flow sounds through the heart due to altered blood composition caused by anaemia
what does biochemistry assess with regards to cardiac function?
kidney values
electrolytes
what are the two cardiac biomarkers used to assess cardiac function?
cardiac troponin I (cTnI)
n-terminal pro-B-type natriuretic peptide (NT-proBNP)
what is cardiac troponin I (cTnI) a marker for?
myocardial cell damage
what is n-terminal pro-B-type natriuretic peptide (NT-proBNP) a marker for?
myocardial stretch (increases with heart failure)
what type of test can be used in cats for n-terminal pro-B-type natriuretic peptide (NT-proBNP)?
snap test
in what sort of environment should BP be measured?
quiet and relaxed
what techniques can be used to indirectly measure blood pressure?
doppler or osscillometric
what should the cuff be level with when measuring BP?
the heart
what is normal systolic BP?
120-140 mmHg
what effect can hypertension have on the heart and heart disease?
increases cardiac workload
can contribute to progression of disease
what may be indicated about heart function by BP lower than 80 mmHg?
decompensated heart failure
what can ECG be used to do in patients with suspected cardiovascular disease?
further characterise findings from auscultation
what may ECG be used to characterise?
bradycardia
tachycardia
irregular rhythm
pulse deficits
what may a Holter monitor (24hr ECG) be used to measure?
intermittent arrhythmias
clinical importance of arrhythmia
response to antiarrhythmatic therapy
how can a Holter monitor be useful in investigating intermittent arrhythmias?
can detect those that may not be seen on a short recording
how can a Holter monitor aid the discovery of the clinical importance of arrhythmia?
suspected cause of syncope
exercise intolerance
can assess the frequency and severity of arrhythmia at home
why does hypertension increase cardiac workload?
more pressure must be overcome by the heart to push blood forwards from the ventricles
what are thoracic radiographs indicated for?
cough
tachypnoea
dyspnoea
how many views should be taken during thoracic radiology?
at least 2
what 2 views must be taken for thoracic radiographs?
right lateral
dorsoventral
what may be shown by thoracic radiography?
congestive heart failure
lung pathology
what may be seen on a thoracic radiograph that indicates congestive heart failure?
pulmonary oedema
distended pulmonary veins
give 2 examples of lung pathology that may be shown on thoracic radiographs
pneumonia
neoplasia
what is cardiomegaly?
increased heart size
what is vertebral heart size?
long and short axis of heart measurements are scaled against the vertebrae and then added to give a score
what is the ideal vertebral heart score for dogs?
<10.7
what is the ideal vertebral heart score for cats?
<8
what factors may indicate cardiomegaly on a thoracic radiograph?
vertebral heart size
elevation of trachea
left atrium enlarged
increased sternal contact
does sternal contact vary between species and breeds?
yes - heart tends to resemble owner
what are the most important congenital cardiac diseases?
stenosis of the great vessels
patent ductus arteriosus
ventricular septal defect
what is stenosis of the great vessels?
narrowing
what are the great vessels most often affected by stenosis?
aorta
pulmonary
what is the most common congenital heart disease in cats?
ventricular septal defect
what are the 3 types of stenosis location?
subvalvular
valvular
supravalvular
how is stenosis of great vessels diagnosed?
echocardiography
what is occurring during subvalvular stenosis?
tissue is blocking blood flow from below the valve
what is occurring during valvular stenosis?
valve itself is unable to open properly
what is occurring during supravalvular stenosis?
narrowing is occurring in the great vessel itself
what is the most common location of stenosis in the aortic valve?
subvalvular
what does aortic stenosis result in?
left ventricular hypertrophy
left sided congestive heart failure
why does aortic stenosis lead to left sided congestive heart failure?
the heart cannot cope with the extra work of pushing blood through the valve
what is the most common location of pulmonic stenosis?
valvular
what is the result of pulmonic stenosis?
right ventricular hypertrophy
right sided congestive heart failure
why does pulmonic stenosis result in right ventricular hypertrophy?
due to the excess work required by the heart to force blood through the narrow channel
what are the clinical signs and findings of stenosis of the great vessels?
often asymptomatic arrhythmias exercise intolerance syncope congestive heart failure
what are the treatments available for stenosis of the great vessels?
beta blockers
balloon valvuloplasty
standard medical management of congestive heart failure
how do beta blockers help to treat stenosis of the great vessels?
reduces the work of the ventricles and protects the heart
what is involved in a balloon valvuloplasty?
balloon is placed across the valve and is used to stretch it open
what type of great vessel stenosis can balloon valvuloplasty be used for?
pulmonic stenosis only
what is cutting balloon valvuloplasty?
use of balloon to break down sub aortic stenosis
what is a ductus arteriosus?
normal fetal connection between pulmonary artery and aorta due to the need to bypass the lungs in utero
what should happen to the ductus arteriosus after birth?
should close after birth when first breaths are taken and form ligamentum arteriosum
what happens if the ductus arteriosus remains patent?
blood flows from the aorta to the pulmonary artery continuously due to the high aortic and lower pulmonary pressure
where is the murmur for patent ductus arteriosus heard?
left heart base - under left arm pit
what may happen to the patient if ductus arteriosus remains patent?
congestive heart failure
when is patent ductus arteriosus often found?
as an incidental finding potentially at vaccination
what are the main treatment methods for patent ductus arteriosus?
interventional closure
surgical ligation of artery
congestive heart failure therapy
how is interventional closure of patent ductus arteriosus performed?
insertion of catheter and device into femoral artery which is then floated up to the heart and placed within ductus arteriosus
what is the most common location of a ventricular septal defect?
upper septum just below the aortic valve
are ventricular septal defects usually symptomatic?
no - often picked up as an incidental finding
describe the murmur associated with a ventricular septal defect
right sided systolic
what murmur is heard with a small ventricular septal defect?
loud
what murmur is heard with a large ventricular septal defect?
soft murmur
why do larger ventricular septal defects lead to softer murmurs?
the larger the defect the lower the pressure of the blood that is pushed through meaning that it makes less noise
how are ventricular septal defects diagnosed?
echocardiography
how are ventricular septal defects often treated?
usually none necessary
heart failure treatment
what is the normal life expectancy of an animal with a ventricular septal defect?
normal if it is small
what are the main acquired cardiac diseases of dogs?
myxomatous mitral valve disease
dilated cardiomyopathy
pericardial effusion
what are the main acquired cardiac diseases of cats?
hypertrophic cardiomyopathy
what is the most common cardiac disease of dogs?
myxomatous mitral valve disease - makes up 75% of cases
what causes myxomatous mitral valve disease?
idiopathic with hereditary/genetic element
what types of dogs often have myxomatous mitral valve disease?
small breed (>20kg)
what are examples of 2 breeds that commonly suffer with myxomatous mitral valve disease?
cavalier king charles spaniel
dachshunds
at what age does myxomatous mitral valve disease often set in?
adult - 7 to 8 years
what valve is most commonly affected by myxomatous mitral valve disease?
mitral
what other valve can be affected by myxomatous mitral valve disease?
tricuspid (right AV)
how is myxomatous mitral valve disease diagnosed?
echocardiography
what are the 2 key effects of myxomatous mitral valve disease?
thickening of valve leaflets
prolapse of valve leaflets
what are the effects of thickening of valve leaflets due to myxomatous mitral valve disease?
regurgitation of blood into atria from ventricles
left atrial dilation
left ventricular dilation
what happens during prolapse of valve leaflets due to myxomatous mitral valve disease?
valve is looser so is pulled back into atria at points during the cardiac cycle
what heart murmur is associated with myxomatous mitral valve disease?
left sided apical systolic heart murmur
how rapidly does myxomatous mitral valve disease progress?
slowly - long asymptomatic period
what may myxomatous mitral valve disease progress to?
left sided congestive heart failure
what is a common cardiac disease of larger dogs?
dilated cardiomyopathy
what causes dilated cardiomyopathy?
idiopathic and hereditary
what large breed dogs are predisposed to dilated cardiomyopathy?
doberman
great dane
newfoundland
what age does onset of dilated cardiomyopathy begin?
4-5
what type of murmur is present with dilated cardiomyopathy?
left apical systolic murmur - not always present
what is dilated cardiomyopathy a disease of?
the myocardium
what does dilated cardiomyopathy lead to?
left ventricular dilation
decreased systolic function
arrhythmias
how is dilated cardiomyopathy diagnosed?
echocardiaography
can dilated cardiomyopathy be asymptomatic?
yes - often for years
what is the prognosis of dilated cardiomyopathy?
guarded - progression may be rapid, particularly in certain breeds
in what breeds can advance of dilated cardiomyopathy be rapid?
doberman
what can dilated cardiomyopathy lead to?
arrhythmias
sudden death
congestive heart failure
what may cause pericardial effusion?
idiopathic
neoplasia
bacterial
(many causes really!)
in what animals is pericardial effusion often seen?
large breed, adult dogs
what is happening during pericardial effusion?
fluid builds up in the pericardial sac and compromises filling of the heart
what is cardiac tamponade?
collapse of right atrium due to high external pressure from filled pericardial sac
how does pericardial effusion affect the heart?
decreases cardiac output
right sided heart failure
why is the right side of the heart usually more affected by pericardial effusion than the left?
lower pressures in the right side of the heart than in the left
how is pericardial effusion diagnosed?
echocardiography
how is pericardial effusion treated?
pericardiocentesis
what position should animals be in for pericardiocentesis?
left lateral
what area of the chest should be surgically prepared for pericardiocentesis?
3rd to 8th intercostal space
what level of sedation is required for pericardiocentesis?
mild
what equipment is used to drain the pericardium?
large catheter or chest drain
how can the correct placement of the catheter in the pericardium be ensured?
echocardiography
what should be checked about the fluid drained from around the heart during pericardiocentesis to ensure that it is from the pericardial sac and not the heart itself?
check for clotting (faster if blood) check PCV (should be lower than blood)
what should be measured with regards to fluid drained during pericardiocentesis?
volume drained
what samples of pericardial fluid should be collected?
cytology - EDTA
culture - sterile
what is the most common cardiac disease in cats?
hypertrophic cardiomyopathy
what are the main causes of hypertrophic cardiomyopathy?
genetic
what age does hypertrophic cardiomyopathy usually set on in cats?
adult - wide age range
what must be excluded before determining hypertrophic cardiomyopathy as the cause of cardiac hypertrophy?
other causes of hypertrophy
what are 2 other causes of cardiac hypertrophy in cats aside from hypertrophic cardiomyopathy?
hyperthyroidism
systemic hypertension
what effect does hypertrophic cardiomyopathy have on cardiac output?
increased thickness of myocardium impairs filling in diastole
how is hypertrophic cardiomyopathy diagnosed?
echocardiography
how may hypertrophic cardiomyopathy be discovered?
incidental finding
what sounds are often heart on auscultation of the heart in a patient with hypertrophic cardiomyopathy?
murmur
gallop sounds
what are gallop sounds?
abnormal extra heart sound
how may animals with hypertrophic cardiomyopathy present?
in heart failure with pleural effusion and pulmonary oedema
with aortic thromboembolysm
what can cause a compensated cat to progress to heart failure rapidly?
stress
anaesthesia
IVFT
what are the signs of aortic thromboembolysm?
sudden onset lameness
cold leg
peripheral cyanosis
pain
where do blood clots often originate from in animals with hypertrophic cardiomyopathy?
atria and ventricles
what is heart failure due to?
disease progression
decompensation of previously stable cardiac failure
development of impedance of cardiac filling (e.g. pericardial effusion)
what are the signs of left sided heart failure?
congestion of pulmonary circulation pulmonary oedema tachypnoea dyspnoea pulmonary crackles cough
in what animals is a cough seen during left sided heart failure?
dogs
what are the signs of right sided heart failure?
congestion of systemic circulation distended peripheral veins positive hepatojugular reflex ascites pleural effusion
what is the hepatojugular reflex?
compression of the liver leading to fluid movement up the jugular
what doe left and right sided heart failure lead to?
decreased cardiac output
what are the physiological signs of decreased cardiac output?
tachycardia
weak peripheral pulses
slow capillary refill time
how may cats in heart failure present that is different to dogs?
with hypothermia and bradycardia
what must be remembered when handling and treating all heart failure patients?
they are very fragile (especially cats) and so need to be in a low stress and calm environment
how is heart failure treated?
diuretic minimise stress oxygen Pimobendan ACE inhibitor Spironolactone water available at all times
what is the name of the commonly used diuretic for heart failure patients?
Furosemide
what is the role of Pimobendan in treating heart failure?
increases heart contractility
what animals is Pimobendan most commonly used in?
dogs
what is the role of ACE inhibitors in treating heart failure?
vasodilator
anti-remodelling
what is the role of Spironolactone in treating heart failure?
weak diuretic and anti remodelling
why must water always be available to patients on diuretics?
risk of AKI if dehydrated
what is the target RR for patients with heart failure?
<40 bpm
what is the target systolic BP for patients in heart failure?
> 100 mmHg
what are the signs that a patient with heart failure is improving?
decreased RR and effort
decreased HR
improved pulse quality
improved CRT
why should heart failure patients be sent home as soon as possible?
less stressful at home
life expectancy is reduced so they should be home with their family as much as possible
what must owners be warned about heart failure treatment?
is lifelong
what can be assessed when looking at ECG?
heart rate whether sinus complexes are normal is HR regular or irregular anything abnormal early or late complexes timings
what are supraventricular complexes?
normal rhythms
what are ventricular complexes?
abnormal ECG complexes
what is the name used for early ECG complexes?
premature
what is the name used for late ECG complexes?
escape
Identify this ECG trace
normal sinus
what is sinus bradycardia?
physiologically normal slow heart rate (e.g. during sleep)
what are the 3 main types of abnormal bradycardias?
atrial standstill
atrioventricular blocks
sick sinus syndrome
what are the 3 types of AV block?
1 to 3
what is happening during atrioventricular block?
AV node is not functioning correctly
how would second degree heart block appear on an ECG?
some P waves not followed by QRS
what is the difference between 1st and 2nd degree AV block?
first is due to slow conduction so there will be and increased P-Q interval
second will involve some conducted P waves and others not
identify the abnormality in this ECG trace
2nd degree AV block
what are the atrial and ventricular heart rates during 3rd degree AV block?
atrial - 200 bpm
ventricular - 40 bpm
what are QRS complexes like in 3rd degree AV block?
wide and bizzare
identify the abnormality shown in this ECG trace
3rd degree AV block
where does supraventricular tachycardia originate?
from the atria
what are the QRS complexes like during supraventricular tachycardia?
narrow but similar to sinus complexes
identify the abnormality shown in this ECG trace
supraventricular tachycardia
describe atrial fibrillation
HR 210 bpm
irregular rhythm
no P waves on ECG
identify the abnormality shown in this ECG trace
atrial fibrilation
where do ventricular arrhythmias originate from?
ventricular myocardium
describe the QRS complexes associated with ventricular arrhythmia
wide and bizzare
identify the abnormality shown in this ECG trace
ventricular arrhythmia
what occurs during ventricular premature complexes?
earlier than expected QRS complex seen on ECG
are ventricular PVC always an issue?
no - unless they are regular / frequent
identify the abnormality shown in this ECG trace
ventricular premature complex
what heart rate is associated with ventricular tachycardia?
375 bpm
what is happening during ventricular tachycardia?
run of ventricular PVC which shorten diastole and affect coronary and global perfusion
identify the abnormality shown in this ECG trace
ventricular tachycardia