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