Diagnosing Heart Disease Flashcards
How are CV cases worked up?
Same as any other case - distance exam - history - PE - define 1* problem - refine - DDx - diagnostic tests > signalment very relevant
What type of disease are young animals predisposed to?
Congential abnormalities
- though cats can acquire abnormalities quite young
How does common disease differ between small and large dogs?
- large dogs usually myocardial disease esp. dilated cardiomyopathy
- small dogs usually valvular disease
What type of cardiac problem are horses predisposed to?
Atrial fibrillation and 2* AV block
What type of cardiac disease do cats mainly present with?
Myocardial disease (1*)
What cardiac defect are ponies predisposed to?
Septal defects
How may sex impact cardiac diseases?
- PDA in bitches
- Dilated cardiomyopathy and mitral valve disease more common in males (or earlier onset)
Which dogs are most afffected by mitral valve disease?
Cavalier King Charles PSaniels
Which dogs are typically affected by dilated cardiomyopathy?
- DOberman, irish wolfhound, great dane
What historical complaints are associated with heart FAILURE?
- dyspnoea
- cough
- excercise intolerance (poor performance)
- lethargy
- ascites
- oedema
- syncope
- collapse
- weight loss
Define heart DISEASE v heart FAILURE
- Disease = any detectable abnormality eg. hearing a murmur, may be no clinical signs until detected on routine exams
- Failure = clinical signs associated with inadequate cardiac output or congestive heart failure
What other systems should be included in DDx?
- Resp
- Neuro
- Musculoskeletal (much more common cause of poor performance in horses)
- Metabolic
What 4 methods of physcial examination should be utilised to diagnose cardic disease?
- Observation
- Palpation
- Percussion
- Auscultation
> in that order!
What sings are you looking for on observation of a potential cardiac case?
- demeanour
- resp effort and rate
- mucous membranes
- body condition
- venous congestion
- ascites
Which mm are commonly paler normally?
Oral often paer than conjunctiva
Where abouts in the oral cavity is CRT best estimated?
Gum/tooth junction
What are the 2 main problems that occour wrt blood vessels in horses?
- thrombosis and thrombophlebitis
> manifest as distension, focal swelling, patency, heat and pain
Which 2 areas should be palpated on a cardio exam? WHat are you palpating for?
> precordium - apex beat ( where heart hits thoracic wall) - location - intensity - rate and rhythm - thrill > Abdomen - ascites - concurrent disease
What are you feeling for when taking the pulse?
- pulse rate and hrart rate same? (pulse deficit if audible contraction not associated with a pulse)
- pulse regular? (regularly irregular or irregularly irregular?)
- quality of the pulse (subjective - strong, weak, thready, bounding etc.)
What can mucous membrane colour tell? egs.
- Pallor: poor peripheral perfusion with vasoconstriction or reduced hemoglobin in the blood (anaemia) differentiate on PCV and quality of arterial pulse
- Cyanosis: presence of adequate haemoglobin but inadequate oxygenation (due to pulmonary oedema/effusion OR R>L shunt)
What signs indicate venous congestion?
- jugular pulses or jugular distension (indicates ^ right atrium pressure)
- veins on ventral abdo obvious
What does ascites indicate?
RHS heart failure in dogs
WHat may percussion help detect?
- thorax (lack of resonance if there is consolidation of underlying lung. May detect a fluid line)
- Fluid thrill in abdomen
How should a dog be postiioned for cardiac auscultation?
standing
Which heart sounds should be audible in the dog and cat? Large animals?
- S1, S2 in small animals
- S1 - 3/4 in large animals
What causes S1 sound? Where is it besst heard?
CLosure of the AV valves at onset of systole
- usually loudest sound
- heard best on left caudally at apex of heart
What causes S2? Where will this be heard loudest?
Closure of the pulmonic and aortic valves at end of systole
- louest at left heart base (cranially)
WHen does systole and diastole occour in relation to the heart sounds?
S1 SYSTOLE S2 DIASTOLE S1
What causes S3 and S4?
> s3
- passive ventricular filling
s4
- active ventricular filling as the atria contract
Are s3 and s4 ever normal in small animals?
NO
- 3rd sound indicates poor relaxation and filling of the ventricle
- Gallop rhythm (Du-Lub-Dup)
How can valvular sounds be listened to in the horse?
Pull leg forward to gain access to heart
What does a murmur indicate?
Turbulent flow in the heart (should always be laminar excpet for cats - innocent murmurs)
- ^ velocity of blood flow
- ^ volume blood flow
- v blood viscosity
- regurgitation across an insufficient valve
Which side is VSD loudest?
Right
Ventricular Septal Defect
When are majority of murmurs heard?
- systole
What is the commonest cause of murmur in aging horses? When iin the cardiac cycle is this heard?
Aortic regurgitation
- heard in diastole
WHat characteristics are used to describe murmurs?
- timing and duration
- intensity
- location (point of maximal intensity)
Which is the most common cause of continous murmurs?
PDA (Patent ductus arteriosus)
What is the most important distinction wrt timing of a murmur?
systolic v diastolic
- systolic between S1 and S2
How can systole be differentiated from diastole is the heart rate is fast?
Palpate femoral pulse - will come up soon after systole
Where is the heart base? What will be heard here?
- cranial (listen under triceps muscle mass)
- outflow tracts
Where is the heart apex? What will be heard here?
- on the left, caudally
- mitral valve will be most audible
What can be heard most clearly on the right?
- tricuspid
Which diseases may not be heard at a valve possition? Where will they be heard?
- PDA: dorsal to the lef heart base
- VSD: Diagonally from left heart apex to right sternal border
How are murmurs graded?
> Intensity
1/6: audible after long period listening, perfect conditions
2/6: clearly audible soon as stethoscope placed over area of max intensity
3/6: clearly audible, loud as heart sounds
4/6: louder than heart sounds, no thrill, radiates widely
5/6: thrill palpable at point of maximum intensity
6/6: audible with stethoscope away from chest
What is the gallop rhythm?
Hearing S3 or S4 in dogs (abnormal)
Which way do aortic stenosis murmurs radiate? Mitral?
- aortic up carotid arteries (can be audible over the head)
- mitral radiate dorsally within thorax
What does the pitch of a murmur indicate?
- high pitch: ejection murmur
- low pitch: regurgitant flow
What type of murmur exhibits a decrescendo? What other descriptions are used for shape?
aortic regurgitation in horses
- an be crescendo, crescendo-decrescendo, decrescendo
What can intensity of heart sounds tell you?
- muffled with pleural or pericardial effusion
- more audible with gross cardiomegaly
What disease may be confused for heart disease?
Respiratory disease with concurrent incidental heart murmur - listen for wheezes and crackles
