Clinical examination of the cardiovascular system Flashcards
Breed predisposition of mitral valve disease
CKCS
Breed predisposition of cardiomyopathy
Dobermans
Breed predisposition of aortic stenosis
Boxers
Cause of syncope/lethargy
Reduced cerebral perfusion
Cause of weakness/reduced stamina
Reduced skeletal muscle perfusion
Cardiac causes of a cough
Mitral valve insufficiency with left atrial enlargement and compression of the left main-stem bronchus
Often in the abscence of heart failures
Softer and moister than resp cough
Cardiac dyspnoea/wheeze/orthopnoea
Due to pulmonary oedema or pleural effusion
What can cause abdominal distension in patients with cardiac disease?
ascites and/or hepatomegaly or splenomegaly
Possible physical exam findings in heart failure
Slow capillary refill time
Pale or cyanosed MM, dry/tacky MM
Jugular venous distension
‘Resp’ signs
Thrill on precordial palpation
Hepatomegaly and/or splenomegaly
Abdominal effusion/ascites
Subcut oedema
Pulse deficits
What causes cyanosed MMs?
Increased quantity of deoxygenated haemoglobin
Arterial saturation less than70% or pAO2 less than 40mmHg
Abdominal effusion/ascites in cadiac patients
Right-sided heart failure produces ascites in dogs
Ascites is less common in cats
The presence of ascitic fluid implies an increase in pressure on the right side of the heart i.e. impairment of pumping of blood into the pulmonary vasculature
What could cause weaker pulses?
Decreased pressure in heart failure or hypovolaemia
What could cause increased pulses?
Anaemia, PDA, aortic regurgitation
What are pulse deficits?
Pulse deficits are present when the pulse rate is less than the heart rate.
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 you to the occurrence of premature ectopic beats.
These may be either supraventricular or ventricular in origin, only the ECG can distinguish these.
What is a hepato-jugular reflux?
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 moderate elevated pressure in the right atrium or right ventricle.
What does a positive heapto-jugular reflux test show?
Indicates that there is elevated pressure in the right atrium or right ventricle.
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.
How to determine strength of the pulse:
Pulse pressure = systolic pressure - diastolic pressure
What is the arterial pulse affected by?
Left ventricular stroke volume
Ejection velocity
The relative compliance and capacity of the arterial system
When do exuberant (bounding) arterial pulses occur?
Patent ductus arteriosus and aortic valve insufficiency
Palpation of the heart
Palpate the precordial impulse – left side 4th –5th intercostal space
Feel for a precordial thrill – caused by vibrations created by turbulence within the heart through the chest wall
What can be identified on heart auscultation?
heart murmurs
gallop rhythms
dysrhythmias
count heart rate - tachycardia/bradycardia
muffled heart sounds due to pleural or pericardial effusions
Diaphragm of the stethoscope used for?
High frequency sounds
Bell of stethoscope used to accentuate:
low-frequency sounds - 3rd and 4th heart sounds in dogs
Where is the apex beat heard?
Over the mitral valve (left apex)
The stethoscope is moved towards the left heart base (2 rib spaces forward and 1/4 chest height up)
Where are aortic and pulmonary valves heard?
Over left heart base
Where can the precordial impulse be felt?
left side 4th - 5th intercostal space (left apex)
What heart sounds are normally heard in cats and dogs?
S1 and S2
What does S1 correlate to?
Closure of the AV valves - start of systole
Loudest at the apex of the heart
What is the intensity of the first heart sound affected by?
It is dependent on the ventricular contractility and therefore is affected by stress and exercise etc.
What does S2 correlate to?
Closure of the semi-lunar valves
Marks the end of systole and beginning of diastole
Loudest at heart base
What could cause the second heart sound to be ‘split’?
pulmonary hypertension e.g. secondary to heartworm
S3 in small animals
Abnormal heart sound
Coincides witht the opening of the mitral valve
Heard in heart diseases that cause dilation of the ventricles (DCM)
Caused by vibrations in a stiffer than normal left ventricular wall
S4 in small animals
Atrial contraction and flow through the AV valve
Occurs before S1
Most commonly heard in cats with HCM where ventricle is over-distended
Difficult to distinguish with a HR over 180
What is a gallop rhythm?
The presence of S3 or S4 (or both)
Split S1 sound
can be heard in some normal large-breed dogs.
Split S2 sound
Occurs when there is asynchronous closure of the semi-lunar valves e.g. when pulmonary hypertension causes delayed closure of the pulmonic valve.
Two mechanisms of heart murmurs
Turbulence of blood flow
Vibration of a cardiac structure
What is used to characterise a heart murmur?
Location, intensity, frequency, timing, quality
What causes heart murmus?
Insufficient valves
Stenotic valves
Interarterial and interventricular defects (holes in the heart)
Arterial - venous communications e.g. PDA
How does blood viscosity affect a heart murmur?
If the viscosity of blood is decreased –> murmur;
If the viscosity of blood is increased –> mask a murmur.
Innocent murmurs
Functional (physiologic) murmurs
Tend to occur in puppies and resolve by 6mo
Characteristics of innocent murmurs
Soft, low amplitude sounds
Occur in early systole
PMI over the left base
Tend to vary in intensity with a change in HR or body position
Aetiology of innocent murmurs
Common in young animals
Common in athletes
Occur in pathologic states as fever, anaemia, and hypoproteinaemia
Aetiology of functional (physiologic) murmurs
common in young animals
common in athletes
occur in pathologic states as fever, anaemia
hypoproteinaemia
Examples of systolic murmurs
Plateau murmurs e.g. AV valve regurgitation, left to right shunting VSD
Ejection murmurs e.g. aortic stenosis or increased blood flow, pulmonic stenosis,
Examples of diastolic murmurs
Aortic regurgitation, pulmonic regurgitation, AV stenosis (rarely audible)
Examples of continuous murmurs
PDA (characteristic machinery murmur), any combination of systolic and diastolic murmur
Grade I murmur
can only be heard after auscultation in a quiet room, unilateral
Grade II murmur
can be heard bilaterally, more easily than I
Grade III murmur
same intensity as the heart sounds
Grade IV murmur
louder than the heart sounds, no precordial thrill
Grade V murmur
louder than the heart sounds, but with a thrill
Grade VI murmur
can be heard with the stethoscope lifted away from the chest wall
What is a precordial thrill?
A vibration on the chest wall due to fluid turbulence within the heart that also causes a heart murmur on auscultation.
Can be palpated by placing the hands on either side of the thorax overlying the heart.
What murmur is systolic, with a PMI at the left base?
Pulmonic stenosis
Aortic stenosis
Subaortic stenosis
What murmur is systolic, with a PMI at the left apex?
Mitral regurgitation
What murmur is systolic, with a PMI at the right mid-heart?
Tricuspid regurgitation
Subaortic stenosis
What murmur is systolic, with a PMI at the right sternal border?
Ventricular septal defect
What murmur is diastolic, with a PMI at the left base?
Pulmonic regurgitation
Aortic regurgitation
What murmur is diastolic, with a PMI at the left apex?
Mitral stenosis
What murmur is diastolic, with a PMI at the right chest wall?
Tricuspid stenosis
