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Puppy and kitten murmurs - Coggle Diagram

- - - - autosomal dominant mode of inheritance has been suggested
  - - - can progress to left sided heart failure
      - secondary mitral regurgitation sometimes develops as a result of left ventricular dilation
      - untreated long standing PDA --> left ventricular myocardial failure develops secondary to chronic volume overload
      - the LA may become very enlarged, predisposing to atrial fibrillation
  - - - if pulmonary artery pressure becomes so high to match or exceed aortic pressure, then flow PDA shunts right to left
        
        results in deoxygenated blood passing the caudal parts of the body only (as brachiocephalic trunk and left subclavian artery arise from the ascending aorta, prior to the ductus)
        
        differential cyanosis
        
        check caudal mucous membranes of the vulva or prepuce (may only be evident after exertion)
    - - cats with L-R PDA have a typical continuous murmur, but cats with pulmonary hypertension may have a systolic murmur without prominent diastolic component
  - - - LA enlargement
      - dilated pulmonary trunk on DV (1-2 o clock)
      - dilated descending aorta (12-1 o clock
      - left auricular appendage enlargement gives bulge at 2-3 o clock on DV
      - all 3 bulges on DV only 25% cases
      - LV enlargement
      - pulmonary over-circulation, leading to pulmonary oedema
    - - tall R waves >4.0mV in dogs
      - wide P waves (P mitral) due to LA enlargement
      - arrhythmias possible - most common atrial fibrillation and supra ventricular arrhythmias
  - - - closure of PDA indicated and typically provides excellent prognosis, most animals live full and normal life
        
        more guarded and difficult to predict prognosis if present in CHF with left ventricular myocardial failure (tx for CHF before anaesthetic)
        
        contraindicated if severe pulmonary hypertension develops and shunting is right to left
    - - surgical ligation
      - closed using a coil or occluder via a trans catheter closure technique
- - - - left sided failure usually results
    - - radiography
        
        LA + LV enlargement
        
        pulmonary venous congestion and pulmonary oedema if left sided heart failure
      - ECG
        
        wide P waves
        
        tall R waves
        
        arrhythmias such as atrial fibriilation
      - echo
        
        LA, LV dilation
        
        dysplastic MV apparatus may be recognised (which mitral valve leaflets, short chordae tendinae, large papillary muscles
        
        abnormal mitral valve motion may be appreciated if mitral stenosis present
        
        mitral regurgitation common
        
        increased velocity mitral inflow
    - - diuretics
      - ACE inhibitors
      - pimobendan
      - prognosis for dogs with moderate-severe mitral dysplasia is generally poor
      - heart rate control is important in dogs with mitral stenosis, esp if atrial fibrillation present
- - - - chronic over circulation of pulmonary vaculature results in pulmonary hypertension
      - cyanosis may be present
      - usually evident before the age of 6 months
  - - - right to left shunting may cause stunting and signs of exercise intolerance
  - - - LV, LA, RV enlargement
      - pulmonary over-circulation if significant L-R shunting
    - - tall R waves
      - wide P waves
    - - LA, LV dilation
      - hyperkinetic LV
      - may image VSD in membranous part of septum below aortic valve and septal leaflet of tricuspid valve
      - doppler :
        
        spectral/colour flow doppler to interrogate the RV side of VSD
        
        turbulent high velocity L-R flow identified
        
        velocity of blood flow across VSD should be measured to assess pressure gradient, the higher the velocity, the better the prognosis
        
        mitral regurgitation common
        
        aortic regurgitation if aortic valve prolapse into VSD
  - - - phlebotomy required and occlusion of defect is contraindicated
- - - - range from complete circumferential band (severe stenosis) to small crescentic area in left ventricular outflow tract (no clinical problems)
      - sub aortic stenosis lesions may not be present at birth, may progress as animal matures
  - - - increased wall stress also compromises coronary perfusion (esp of subendocardium)
        
        myocardial ischaemia can lead to ventricular arrhythmais
        
        exertion syncope can result
        
        risk of sudden death
        
        myocardial failure or CHF may occur in long standing cases of severe AS
  - - - cardiac silhouette often unremarkable, LV enlargement may be recognised
      - post stenotic dilation of aorta on DV view
    - - concentric LV hypertrophy in more severe cases
      - anatomical abnormalities of LVOT and aortic valve may be recognised e.g. fibrous ridge in LVOT
      - post stenotic dilation of ascending aorta
      - doppler
        
        maximal aortic velocities >2.25m/s arbitrarily defined as AS
        
        turbulent high velocity aortic flow
        
        aortic insufficiency common
  - - - medical management based on beta-adrenergic antagonists (beta blockers)
- - - - RV hypertrophy
        
        may cause infundibular narrowing of RVOT and worsen stenosis
        
        severe or long standing cases can progress to right sided heart failure
  - - - distended jugular veins
      - hepatomegaly
      - ascites
      - positive hepatojugular reflux
  - - - RV enlargement with apex tipping on the lateral view
      - post stenotic dilation of the pulmonary trunk
      - normal/underperfused pulmonary vasculature
      - may appear normal if mild lesion
      - angiography will confirm dx
    - - deep S waves in I, II, II leads and avf
      - right axis deviation in frontal plane
      - +/- ventricular premature complexes (RV origin)
  - - - high velocity and turbulent flow across pulmonic valve
      - dynamic outflow tract obstruction common in moderate to severe cases
      - pulmonic regurgitation common
      - +/- tricuspid regurgitation
  - - - indications for this include clinical signs caused by PS (exercise intolerance, syncope) or doppler pressure gradient >80mmHg
- - - - left heart enlargement or a bulge in aorta or pulmonary artery
- - - - RV enlargement
      - hypovascular lung fields
    - - deep S waves in leads I, II, III and aVF, right axis deviation
    - - RV hypertrophy
      - flat inter ventricular septum or paradoxical septal motion
      - VSD visible if large enough
      - aortic malalignment (overlying VSD)
      - pulmonary trunk hypoplastic, can be difficult to locate
      - PS - high velocity and turbulent pulmonic flow
      - VSD - low velocity shunting R-L