Congenital Heart Defects Flashcards
congenital valve defects
- sub aortic stenosis
- pulmonary stenosis
- mitral valve dysplasia
- tricuspid valve dysplasia
- cor triatriatum sinsiter/dexter
congenital shunt defects
- PDA
- VSD
- ASD
what species/breeds are predisposed to sub aortic stenosis
large breed dogs (Goldens, Rottweilers, newfoundlands)
murmur for sub aortic stenosis
left basilar systolic ejection murmur
what is the primary lesion in sub aortic stenosis
ridge/ring underneath the aortic valve
what are secondary lesions in sub aortic stenosis
- concentric hypertrophy of the LV from pressure overload
- aortic insufficiency
- post stenotic dilation of the aorta
- AV endocarditis
what are signs of subaortic stenosis on echo
- increased aortic outflow velocity
- thick LV wall
- fibrosis in LVFW
what treatment is there for sub aortic stenosis
B blockers (atenolol) to reduce load/demand on heart
what species/breed is predisposed to pulmonary stenosis
small breed dogs, brachycephalics
murmur for pulmonary stenosis
left basilar systolic ejection murmur
what is the primary lesion in pulmonary stenosis
fusion or thickening of the valve leaflets
what are secondary lesions in pulmonary stenosis
- concentric hypertrophy of the RV from pressure overload
- pulmonary insufficiency
- post stenotic dilation of PA
what are signs of pulmonary stenosis on echo
- increased pulmonary outflow velocity
- RV wall thickening
what is the treatment for pulmonary stenosis
beta blockers (atenolol)
+
balloon valvuloplasty
what are the clinical differences between subaortic and pulmonary stenosis
SAS murmur has carotid radiation (can be heard in carotid sinuses), PS does not
SAS have weak/delayed pulses, PS has normal pulses
BREEDS
- large: SAS
- small: PS
what species/breeds are predisposed to mitral valve dysplasia
RARE in most species
dogs: bull mastiffs, bull terriers, labs
some cats
murmur for mitral valve dysplasia
left apical systolic regurgitant murmur
what is the primary lesion in mitral valve dysplasia
irregular valve architecture
OR
irregular chordae attachments
what are the secondary lesions in mitral valve dysplasia
- eccentric hypertrophy of the LV from volume overload
- LA dilation
- mitral valve insufficiency
what are signs of mitral valve dysplasia on echo
- LA and LV enlargement
- papillary muscle anomalies
what is the treatment for mitral valve dysplasia
no fix - treat the CHF
what species/breed is predisposed to tricuspid valve dysplasia
labradors
murmur in tricuspid valve dysplasia
right apical systolic regurgitation murmur
what is the primary lesion in tricuspid valve dysplasia
irregular architecture
OR
irregular chordae attachments
what secondary lesions are in tricuspid valve dysplasia
- eccentric hypertrophy of the RV from volume overload
- tricuspid insufficiency
- RA dilation
what are signs of tricuspid valve dysplasia on echo
- RA and RV enlargement
- papillary muscle anomalies
what treatment is there for tricuspid valve dysplasia
no fix - treat the CHF
cor triatriatum sinister vs dexter
sinister: affects the LEFT atrium
dexter: affects the RIGHT atrium
what species are predisposed to CT sinister vs dexter
sinister: cats
dexter: dogs
what is the primary lesion in CT sinister/dexter
abnormal vessel entry into the atria
sinister: pulmonary veins enter incorrectly into LA
dexter: caudal vena cava enters incorrectly into RA
what is the treatment for CT sinister/dexter
balloon valvuloplasty and treat the CHF
what species are predisposed to PDA
dogs
murmur in PDA
left basilar continuous murmur
what is the primary lesion in PDA
incomplete ductal muscle causes failure of DA closure at birth
causes blood to flow from aorta to PA
what are the secondary lesions in PDA
- eccentric hypertrophy of the LV from volume overload
- pulmonary over circulation
- aortic dilation, possibly PA dilation
what are signs of PDA on echo
- visualize the PDA
- continuous flow from aorta to PA throughout systole and diastole
- flow peaks velocity during systole
what kind of pulses are seen with PDA
hyper dynamic (bounding) due to low diastole pressure
what is the treatment for PDA
surgery - ductal occlusion
what species are predisposed to VSD
cats, horses, cows, camelids
restrictive vs nonrestrictive VSD
restrictive: very small opening between R and L ventricles
nonrestrictive: large opening between R and L ventricles
murmurs in restrictive/nonrestrictive VSD
restrictive: very loud/harsh right sided murmur
nonrestrictive: none; blood flow is too slow due to the equilibrium of pressures
what is the primary lesion in VSD
opening in between R and L ventricles causing blood to flow from LV to RV to pulmonary circulation back to LV
what are the secondary lesions in VSD
- eccentric hypertrophy of the LV from volume overload
- pulmonary overcirculation
what are signs of VSD on echo
- color flow from LV to RV
- high velocity flow if restrictive, low velocity if nonrestrictive
what is the treatment for VSD
restrictive: none, usually subclinical
nonrestrictive: surgical closure if only involving muscular; or just treat CHF
what species/breeds are predisposed to ASD
dogs (standard poodles), horses, cows, camelids
murmur in ASD
left basilar systolic murmur
**NOT diastolic even though shunt is during diastole because it is slow flow - the fast flow occurs on the L side during systole as the LV pushes out the larger volume
what is the primary lesion in ASD
opening between LA and RA
flows from LA to RA to RV then through the lungs back to the LA
LV never sees the increased load so even though its a L to R shunt, it causes R SIDED CHF
what are the secondary lesions in ASD
- eccentric hypertrophy of the RV from volume overload
- pulmonary overcirculation
- RA dilation
what treatment is used for ASD
none - usually asymptomatic
what defect causes a splintered QRS complex on ECG
tricuspid valve dysplasia
what defect causes a tall QRS and wide P wave on ECG
PDA
what defect causes a prominent Q wave on ECG
VSD
what is eisenmenger syndrome and which defects can cause it
chronic, unresolved L to R shunting defects can lead to pulmonary hypertension, causing R sided pressure to exceed L sided pressure, leading to shunt reversal
symptoms of eisenmenger syndrome
- cyanosis
- PDA: differential cyanosis of the caudal half
- VSD/ASD: generalized cyanosis - polycythemia
- deoxygenated blood reaching kidneys stimulates EPO production
tetralogy of fallot
combination of 4 heart defects:
1. pulmonary stenosis
2. VSD
3. overriding aorta
4. RV concentric hypertrophy
clinical signs of tetralogy of fallot
exercise intolerance, collapse, generalized cyanosis, R-CHF, polycythemia
what is the normal ventricular outflow velocity (both R and L)
<2 mm/s
what is the normal ventricular outflow pressure gradient
16 mmHg
(4x2^2 = 16)
what is the pressure gradient during mild semilunar valve stenosis
25-50 mmHg
what is the pressure gradient during moderate semilunar valve stenosis
50-80 mmHg
what is the pressure gradient during severe semilunar valve stenosis
> 80 mmHg
