Approach - Diagnosis and physical exam Flashcards
What are large breed middle age dogs prone to?
myocardial disease
What are small breed old dogs more likely to have?
Primary valvular disease
What are larger horses more likely to develop?
AF
What defect are ponies more likely to have?
septal defects
In dogs, are PDAs more common in males/females?
Females
What signalment if DCM most common in?
Males in some breeds, occurs at an earlier age in males. (THEORIES: oestrogen protective, testosterone destructive?)
Which breed is over-represented in MVD?
CKCS
What size of dog is prone to valvular defects versus DCM?
DOGS:
20kg = DCM (Great Danes, Irish Wolfhounds and Dobermans)
What are common historical complaints of heart disease?
Dyspnoea Cough Exercise intolerance/poor performance Lethargy Ascites Peripheral edema (often dependent, more likely in horses and cattle) Syncope Collapse Weight loss
BUT REMEMBER THAT ALL OF THESE ARE RELATIVELY NON-SPECIFIC
Define WNRFE
Will not run fast enough (!) - horses!
What is air hunger?
When you concentrate on nothing other than breathing.
What should you observe on a CVS exam?
Demeanor Respiratory rate and effort MM BCS Venous congestion Ascites
What do cyanotic MM imply?
Indicuates the presence of adequate Hb but inadequate oxygenation. Arises in one of 2 ways:
- ) Problem with oxygenation (pleural effusion of pulmonary oedema)
- ) Right to left shunt (deoxygenated blood ejected into systemic circulation)
How do you spot venous congestion?
If there are jugular pulses or jugular venous distension. Veins on the ventral abdomen can be obvious.
Define dyspnoea
Increased respiratory effort
Define tachypnoea
Increased respiratory rate
What is the most reliable oral site for taking CRT?
gum/tooth junction
What are the major problems with the major blood vessels in horses?
Thrombosis and thrombophlebitis
What should you palpate on CVS exam?
PRECORDIUM - apex beat, location, intensity, rate and rhythm, presence of thrill
ABDOMEN - ascites, concurrent disease.
What does a palpable thrill on the precordium indicate?
Grade 5 or greater heart murmur
Define pulse deficit
When the pulse rate is lower than the audible HR, usually indicative of arrhythmia
What might ascites indicate? 2
Hepatomegaly
Splenomegaly
Where might you take the pulse in the horse?
Coccygeal - cattle Ext. maxillary/facial Transverse facial Median Digital
Normal adult horse HR
28-42 bpm
Normal yearling horse HR
up to 80bpm
Normal neontal foal HR
up to 100bpm
Normal adult cattle HR
55-80 bpm
Normal calve HR
up to 100bpm
Normal adult sheep/goat HR
70-90bpm
Normal adult pig HR
60-90bpm
Why percuss the precordium on CVS exam?
To detect fluid lines and/or areas of dullness
Why percuss the abdomen on CVS exam?
Detection of fluid thrill
Best position to auscultate an animal?
With the animal standing so the heart is in its natural anatomic site
What heart sounds are normally audible in the dog?
S1 and S2. (Lub-dup)
S3 and/or S4 may normally be audible in large animals though not every case.
What is S1?
Sounds generated in heart and surrounding structures at onset of systole on closure of the AV valves. Usually loudest heart sound and is heard best over the LEFT APEX.
What is S2?
Corresponds to the sounds generated in the heart and surrounding structures on closure of the pulmonic and aortic valves. This represents the end of systole and will be loudest at the LEFT heart BASE.
What happens between S1 and S2?
Ventricular systole
What happens between S2 and the following S1?
Diastole, much more variable in length. Pulse will rise during systole.
What is S3?
Corresponds to ventricular filling. The ventricle relaxes and the blood passively flows in from the atria to the ventricle (approximately 73% filling is passive).
What is S4?
corresponds to active ventricular filling as the atria contract. Blood is forced into the ventricle.
What if S3 or S4 are heard in small animals?
This always indicates an abnormality.
What does an audible diastolic sound imply?
that the ventricle is not filling normally - i.e. there is poor relaxation. This is described as a ‘gallop’ rhythm and sounds like Du-Lub-Dup.
How can you characterise a gallop as S3 or S4?
Only way is to record a phonocardogram but differntiating whether gallop is due to S3 or S4 is not likely to be of significance anyway.
What does splitting of S1 or S2 indicate?
asynchronous closure of the AV or outflow valves (a split S2 can occur if there is pulmonary hypertension - the pulmonic valve closes after the aortic valve).
Why might a murmur be present? 4
Increased velocity of blood
Increased volume of blood
Reduction in blood viscosity
Regurgitation across insufficient/leaking valve
When are the majority of murmurs heard?
During systolie since this is the most active period of the cardiac cycle when ejection occus and ventricular pressures (thus intracardiac pressure gradients) are greatest)
What is one of the more common causes of murmurs in aging horses?
Aortic regurgitation –> diastolic murmur
Where do you hear pulmonic and aortic valves?
Left heart base - ribspaces 3/4 on LHS
Where do you hear the mitral valve?
Left heart apex
What do you hear on the right side?
Typically hear tricuspid. VSD is loudest on the right.
How are murmurs described? 6
Timing/Duration
Intensity/audibility
Location (point of maximal intensity)
Also:
radiation
pitch
shape
What is a continuous murmur?
Example?
Murmur is present throughout systole and diastole. Classic example is PDA, other causes possible.
What may cause a left apex diastolic murmur?
Mitral stenosis
What may cause a left base diastolic murmur?
Aortic or pulmonic insufficiency
What might cause a right cranial diastolic murmur?
Aortic insufficiency
Possibly tricuspid stenosis
How do you auscultate the outflow valves?
They are fairly cranial so you have to move the stethoscope under the triceps muscle mass which may necessitate moving the animal’s leg forward on that side.
Where may a PDA be heard?
Dorsal to the left heart base
Where may a VSD be heard?
‘Diagonal’ from the left heart apex to the right sternal border.
How are murmurs graded?
Out of 6 for intensity:
- ) Barely audible, ideal conditions,
- ) Clearly audible at PMI, doesn’t radiate
- ) Clearly audible, as loud as S1, S2 may radiate
- ) Louder than S1 and S2 but no thrill palpable, likely to radiate widely across the thorax
- ) Precordial thrill palpable over the PMI at skin surface
- ) Audible with stethoscope off thorax
Define murmur radiation
When a murmur is audible at a site other than the PMI. It will radiate more loudly in certain direction due to the direction of the turbulent jet OR along structure adjacent to the site of origin of the murmur.
Where do aortic stenosis murmurs radiate?
Up the carotid arteries, sometimes audible over the head
Where do mitral murmurs radiate?
Radiate dorsally within the thorax.
What are high pitch murmurs more likely to be?
ejection murmurs
What are low pitch murmurs more likely to be?
regurgitant flow
When are pitch descriptions of murmurs most useful? 2
to establish if a murmur has changed OR if more than one murmur is present in the same animal.
Describe murmur shape
the description of appearance on phonocardiogram
What is the shape of a crescendo-decrescendo murmur?
diamond-shape
What shape is a pansystolic murmur?
plateau
Under what conditions do heart sounds vary?
BCS and thoracic shape. Muffled with pleural or pericardial fluid. May be more audible if there is gross cardiomegaly.
What happens in many small dogs that have lung disease?
They also have incidental heart murmurs. Listen for wheezes and crackles over the lung fields.
What do lung crackles indicate?
pulmonary oedema
Crackles (rales) indicate alveoli and small airways snapping open at the end of inspiration. Can also occur with respiratory disease e.g. pneumonia and pulmonary fibrosis
What do wheezes/stertorous inspiratory noise indicate?
Respiratory disease as a more likely cause of clinical signs.
