Congenital Heart Disease Flashcards
What are the 3 most common congenital heart diseases in dogs?
Patent ductus arteriosus (PDA) Subaortic stenosis (SAS) Pulmonic stenosis (PS)
What are the 3 most common congenital heart disease in cats?
Ventricular septal defect (VSD)
Tricuspid valve dysplasia (TVD)
Mitral valve dysplasia (MVD)
What is a patent ductus arteriosus?
Ductus arteriosus patent after birth
Blood flows from the aorta to pulmonary artery
Patent ductus arteriosus results in a ___________ overload to the _____ side of the heart
Volume; left
What type of hypertrophy would you expect in a patent ductus arteriosus?
Eccentric - volume overload
What breeds are predisposed to PDA?
Bichon Chihuahua Poodle GSD Corgi Shetland sheepdog
T/F: PDA is more commonly see in males rather than females
False
Female>male
Continuous heart murmur with PMI at bases
High grade
Heart rate normal to high
Bounding femoral pulse
Asymptomatic
PDA
If PDA results in CHF, what clinical signs will you see?
Exercise intolerance Tachypnea Cough Dyspnea Syncope
Abnormal lung sounds
How can you definitively diagnose PDA?
Echocardiography
-turbulent blood flow
What is the treatment of PDA?
Curable by surgical ligation/trans catheter occlusion
Both procedures require specialists
Transcatheter occulsion is minimally invasive
What is reversed PDA??
Right (deoxygenated) to left (oxygenated blood) shunt
Occurs secondary to severe pulmonary hypertension (PA > aortic pressure)
Reversed PDA can result in??
Hypoxemia and polycythemia
Often symptomatic and have differential cyanosis (cranial or caudal depending on if it joins before or after the subclavian arteries
T/F: reversed PDA s correctable by ligation or occlusion similar to a left-right PDA
False
Non correctable
How are reversed PDAs managed?
Exercise restriction
Phlebotomy
Bone marrow suppression drugs (hydroxyurea)
What disease has subvalvular fibrosis
Subaortic stenosis (SAS) -nodule/ridge/ring/tunnel
Not always congenital
How does subaortic stenosis affect bloodflow?
Obstructs blood as it flows from the LV to the aorta
-LV must generate higher pressure to maintain cardiac output
SAS results in ________ overload to the _____ side of the heart
Pressure; left
What type of hypertrophy would you expect in SAS?
Concentric -pressure overload
What is the signalment for SAS?
Dog> cat
Large and giant breed
-golden, Newfoundland, Rottweiler, GSD, boxer
Dog Left basilar systolic murmur Med grade Heart rate normal to high Weak femoral pulse
Asymptomatic
SAS
If CHF develops -> abnormal lung sounds, tachypnea, and dyspnea
How can you definatively diagnose SAS?
Echocardiography
Severity of a SAS can be determined how?
Continuous wave Doppler
Used to measure velocity of blood as it is ejected out of LV
Estimated pressure gradient (PG)=4 x velocity^2
Mild if PG < 40mmHg
Moderate 41-80mmHg
Severe > 80mmHg
Dogs with SAS can develop what potentially fatal arrhythmia?
Ventricular arrhythmia
How is SAS treated?? What patients would be indicated?
No curative treatment
Atenolol (b blocker) can decrease myocardial O2 demand, improve perfusion, and prevent ventricular arrhythmia
—> moderately/severely affected dogs
Balloon valvulopasty
SAS is a risk factor for ____________
Endocarditis
—> patients with SAS should receive antibiotics for any potentially bacteremic episode
High velocity can damage endothelium
What is valvular pulmonic stenosis?
Markedly thickened cusps due to dysplasia +/- commissural fusion or annular hypoplasia
How does pulmonic stenosis affect blood flow?
Obstructs blood as it flows from the right ventricle to the main pulmonary artery
—> RV must generate higher pressure to maintain cardiac output
PS results in _________ overload to the _______ side of the heart
Pressure; right
What type of hypertrophy do you expect in pulmonic stenosis ?
Concentric - pressure overload
What is the signalment commonly seen with PS?
Dog> cat
Terrier Bulldog Beagle Samoyed Chihuahua Labrador
Dog
Left basilar systolic murmur
Any grade
Heart rate normal-high
Femoral pulses are normal
Pulmonic stenosis
If pulmonic stenosis lead to congestive heart failure, what clinical signs would you see?
Jugular venous distention
Abdominal distention
Tachypnea
Dyspnea
Right sided CHF—> systemic congestion
Definitive diagnosis requires of pulmonic stenosis requires??
Echocardiography
Where would you see a bulge on the heart if there was pulmonic stenosis
1-2 o’clock
What is the treatment of pulmonic stenosis ?
Mildly affected+asymptomatic - normal lifespan, no treatment
Balloon valvuloplasty if PS is /moderate/severe (80mmHg)
Atenolol can reduce arrhythmia, dynamic infundibular gradient, syncopal events, and risk of sudden death
If you are considering a balloon valvuloplasty surgery in a bulldog/boxer, what would you be concerned about ?
Can have anomalous coronary artery (branching from aorta and wrapping under pulmonary artery)
—> valvuloplasty can cause rupture
What is a ventricular septal defect (VSD)? How does it impact blood flow?
Defect in the inter ventricular septum
LV>RV pressure
Blood from the left goes to the right ventricle
Ventricular septal defect (VSD) causes a _____________ overload to the ______ side of the heart
Volume; left
What type of hypertrophy do you expect in VSD?
Eccentric - volume overload
What is the most common concurrent congenital defect in dogs with VSD?
Pulmonic stenosis
T/F: if severe pulmonary hypertension develops or severe PS is present along with VSD, the shunt can reverse (right ->left)
True
What is the signalment for VSD?
cats>dog
English springer spaniel West highland white terrier Lakeland terrier Basset hound English bulldog
Cat
Systolic murmur with PMI parasternally
Heart rate normal or high
Femoral pulse normal
Ventricular septal defect
T/F: the smaller the VSD, the launder the murmur
True
What diagnostics can you use in VSD?
Echocardiography
Doppler - ID small defects
Radiographs —> pulmonary over circulation
Moderate/large defects cause more significant chamber dilation (left sided or biventricular) and pulmonary hypertension
Treatment for VSD?
Small VSDs do not require treatment
Moderate/large—> cardioprotective(ACEi)
Large defects —> PA banding or open-heart surgery (poor prognosis if not closed)
What is tricuspid valve dysplasia (TVD)?
Thickening/elongated/shortened leaflets
Shortened/absent cordae tendineae
Abnormal papillary mm.
How does tricuspid valve dysplasia (TVD) affect blood flow?
TV regurgitation is the most common result, but stenosis can also occur
TVD results in _______ overload to the __________ side of the heart
Volume; right
What type of hypertrophy do you expect in TVD?
Eccentric - volume overload
What other cardiac abnormality can you see in TVD due to high right atrial pressure?
Patent foramen ovale
What is the signalment of TVD?
Cats> dog
Lab
Boxer
Irish setter
GSD
Cat
Right apical systolic murmur
Heart rate normal or high
Femoral pulses are normal
Tricuspid valve dysplasia
What signs would you observe is there was CHF due to TVD?
Jugular venous distention
Pulsation/abdominal distention
Tachypnea/dyspnea
How can you definitively diagnose TVD?
Echocardiography
- when tricuspid regurgitation is severe, the left ventricle is usually small (volume underload)
- when stenosis is present, RA is dilated and RV is small
What is the treatment for TVD?
Mild- no treatment required
Moderate/severe- cardioprotective drug(ACEi)
In severe cases can develop CHF
- > surgical valve replace the
- > interventional therapy with balloon valvuloplasty
What is mitral valve dysplasia
(MVD)?
Any part of the valve can be affected
Short/thick leaflets with an occasional cleft
Short/thick/long/thin cordae tendineae
Annular enlargement, malposition of papillary mm.
T/F: mitral regurgitation is most common, but stenosis can also occur
True
Mitral valve dysplasia results in _____________ overload to the ______ side of the heart
Volume; left
What type of hypertrophy do you expect in mitral valve dysplasia?
Eccentric - volume overload
What is the signalment of MVD?
Cat>dog
Great Dane GSD Bull terrier Golden retriever Newfoundland
How can animals with MVD present ?
Asymptomatic or L-sided CHF
Left apical systolic murmur
If there is a stenosis, may hear a diastolic murmur
CAT
Left apical systolic murmur
Heart rate may be normal or high
Femoral pulse normal
Mitral valve dysplasia
What is the definitive diagnosis for MVD?
Echocardiography
If stenosis is present - LA dilated and LV small
Thoracic radiographs are useful for determining LA/LV enlargement and CHF
How do you treat MVD?
Mild -does not require treatment
Moderate/severe -cardioprotective drug
Beta blocker in patients with LV outflow obstruction
Many with severe MVD develop CHF—> surgical repair/replacement of valve/balloon valvuloplasty
Atrioventricular septal defects are most common in what species?
Cats»_space; dogs
What congenital heart disease has its PMI at left/right parasternal,diastolic, or systolic ?
Atrioventricular septal defects
—> no surgical/interventional therapy
—>can develop CHF and sudden death
What is tetralogy of fallot (ToF)?
Pulmonic stenosis
Secondary concentric hypertrophy of the right ventricle
Overriding aorta
Ventricular septal defect
How is the blood flow affected during tetralogy of fallot?
High pressure in the RV (secondary to PS) —> deoxygenated blood from the RV shunts into the LV
—> hypoxemia and polycythemia
What is the most common cause of cyanotic heart disease in cats and dogs?
Tetralogy of Fallot
What is the treatment of ToF?
Non-selective beta blocker (propranolol)
Exercise restriction
Phlebotomy
+/- hydroxyurea
Partial balloon valvuloplasty
Surgical
Open-heart repair of VSD and PS
What defect allows blood to flow from the left atrium and right atrium?
Atrial septal defect
->murmur is common and often low grade
What is persistent right aortic arch?
Vascular ring anomaly (VRA) characterized by persistence of the right fourth aortic arch during fetal development
—> esophageal signs- regurgitation
What type of murmur is only ever systolic and low grade, usually heard in the base of the heart
Innocent heart murmur
Where is the PMI of a innocent heart murmur?
Aortic/pulmonary valve (left heart base)
What causes a innocent heart murmurs and what animals do you see it in?
Murmur caused by high velocity flow through an immature CVS
NOT a structural heart disease
Puppies and kittens - usually disappear by 6months of age