Congenital Heart Disease Flashcards
what are the three most common congenital heart diseases in dogs?
patent ductus arteriosus, subaortic stenosis, and pulmonic stenosis
what are the three most common congenital heart diseases in cats?
ventricular septal defect, tricuspid valve dysplasia, mitral valve dysplasia
what sort of shunt is present in PDA?
L-R shunt UNLESS reversed then R-L shunt occurs
what is the cause of a PDA?
ductus arteriosus (ligamentum arteriosum in adults) remains patent after birth
=communication between PA and aorta
what type of hypertrophy do you see in PDA?
eccentric (volume overload to left side of heart)
bichons, chihauhaus, poodles, GSDs, corgis, and shetland sheepdogs are all breeds predisposed to what congenital heart dz?
PDA
what type of heart murmur does a patient with PDA have?
continuous with PMI at left base, usually high grade (IV-VI)
what are most femoral pulses like in patients with PDA?
strong or “bounding” (lower diastolic pressure so pulse pressure difference larger)
what are two ways you can cure PDA?
surgical ligation (thoracotomy) or transcatheter occlusion
what test can you do to look for PDA in which you inject a radiopaque dye to highlight it?
angiography
reversed PDA occurs secondary to what?
pulmonary hypertension (PA pressure > Ao pressure)
T/F: PDA is often symptomatic whereas reversed PDA is often asymptomatic
FALSE, PDA often asymptomatic unless develops develops CHF). reversed PDA is often symptomatic (hypoxemia, polycythemia, differential cyanosis)
what heart sounds might you hear with reversed PDA?
split S2, +/- murmur
how do you manage a patient with reversed PDA?
exercise restriction, phlebotomy, +/- bone marrow suppression drugs (hydroxyurea)
fibrous or fibrocartilaginous subvalvular lesion creating a nodule, ridge/ring, or “tunnel” leading to obstruction of blood from LV to aorta is describing what type of congenital heart disease?
SAS
what type of hypertrophy do you see with SAS?
concentric (pressure overload to left side)
what might you see on a radiograph of a patient with SAS?
prominent ascending aorta and L-sided cardiomegaly
T/F: SAS is most often seen in small or toy breed dogs
FALSE, usually LBD (g. retriever, newfoundland, rottweiler, GSD, boxer)
dogs with SAS tend to be asymptomatic. if moderate-severe and symptomatic, what signs might you see?
exercise intolerance, syncope, L-CHF signs, sudden death
what murmur is seen in patients with SAS?
left basilar systolic (often holosystolic) murmur, any grade
aortic regurg?? + diastolic murmur
a continuous wave doppler in an echo of a dog with SAS is helpful for what?
measures velocity of blood ejected in systole from LV so estimates pressure gradient which determines severity
mild: <40 mm Hg
mod: 41-80 mm Hg
severe: >80 mm Hg
what is the main cause of sudden death in dogs with SAS?
lethal ventricular arrhythmias
may see R-on-T (ventricle depolarizes before done repolarizing)
there is no curative treatment of SAS but what drug might you consider to improve MST?
atenolol (beta blocker)
decreases myocardial oxygen demand, improves myocardial perfusion, may reduce ventricular arrhythmias
why might you give a patient with SAS antibiotics?
because SAS is a risk factor for endocarditis, high velocity blood flow damages valve and walls increasing its chances for bacteria to take advantage (i.e. diastolic murmur and aortic regurgitation)
is valvular pulmonic stenosis more common in dogs or cats?
dogs
in pulmonic stenosis there is usually markedly thickened cusps due to dysplasia +/- commissural fusion or annular hypoplasia
TRUE, limits the opening for blood
what type of hypertrophy results from PS?
concentric (pressure overload)
what types of breeds more commonly have PS?
terriers, english bulldogs, beagles, samoyeds, chihauhaus, labs
T/F: due to the high pressure buildup from the stenosis, dogs who have PS are often symptomatic
FALSE, usually asymptomatic
would you expect to see L-CHF or R-CHF in a dog with PS?
R-CHF (issue is getting blood from the right ventricle to the pulmonary artery)
what type of murmur would you expect in a patient with PS?
left basilar systolic (often holosystolic) murmur, any grade
T/F: the end of the right ventricle is on the left side of the chest
TRUE, crescent shape (think PAM for auscultation on the left side)
what anomoly can bulldogs or boxers have that might cause you to reconsider balloon vulvuloplasty for PS?
anomalous right coronary artery (artery wraps around the pulmonary trunk, BV can cause to rupture)
when should you consider balloon valvuloplasty in a patient with PS?
consider if PG 50-80 mm Hg, indicated if > 80 mm Hg
a balloon valvuloplasty in a patient with PS is considered successful if the reduction of PG is what?
> 50%
what drug may help to reduce arrhythmias in patients with PS?
atenolol
where are ventricular septal defects usually located?
high in the perimembranous region
what type of shunt do you see in a VSD?
L > R shunt
what type of hypertrophy do you see in a VSD?
eccentric (volume overload to left side)
concurrent congenital defects are common in dogs with VSD, what one is MOST common?
pulmonic stenosis
what happens if severe pulmonary hypertension develops or a severe PS is present in a dog with VSD?
shunt will reverse!! (pressure becomes higher in pulmonary artery than left ventricle and blood begins to flow from R > L instead)
are VSDs more common in cats or dogs?
CATS, dogs (english springer spaniel, west highland white terrier, lakeland terrier, basset hound, english bulldog)
T/F: VSDs are often asymptomatic, but if large can result in L- or biventricular CHF
TRUE
in a patient with VSD, what type of murmur do they have and where is it usually loudest?
systolic, right parasternal region
smaller the defect, the louder the murmur
what treatments might you consider for a patient with VSD?
mod-large: cardioprotective drugs
interventional (catheter-based) options > occlude/plug defect
*large require PA banding or open-heart surgery (increase pressure on right side to decrease L > R flow)
what part of the valve is usually affected by tricuspid and mitral valve dysplasia?
any part! thickened/elongated/shortened leaflets, shortened/absent chordae tendinae, abnormal papillary mm.
what can occur as a result of TVD?
TV regurgitation > stenosis
what type of hypertrophy do you see with TVD?
eccentric (volume overload to right side)
T/F: the foramen ovale may remain patent due to high right atrial pressure in TVD
TRUE
are TVD more common in cats or dogs?
CATS, dogs (labs, boxers, irish setters, GSD)
what type of CHF do you see in a patient with TVD?
right-sided CHF
what type of murmur would you expect in a patient with TVD?
right apical systolic murmur, can be low grade even with severe disease
stenosis? may hear diastolic murmur
T/F: when tricuspid regurgitation is severe the RV is usually small
FALSE, left ventricle
what sign on an ECG could you see that might lead you to believe you have a TVD?
“splintered” QRS complexes
a patient who has TVD has stenosis as well, grossly what would you expect the heart to look like?
RA is dilated, RV is small
what would you prescribe patients with moderate or severe TVD or MVD?
cardioprotective drugs
what would you recommend for a patient with severe TVD or MVD and CHF?
surgical valve replacement, balloon valvuloplasty
shortened lifespan!
T/F: valve dysplasias will present with systolic murmurs when stenosis is present and diastolic murmurs when regurgitation is present
FALSE, opposite
regurgitation > systolic
stenosis > diastolic
when stenosis is present in MVD the LA is small and the LV is dilated
FALSE, the LA is dilated and the LV is small
your patient with MVD has a LV outflow tract obstruction, what drug therapy might be helpful?
beta blocker therapy
complex congenital defects involving the AV septum, atrial septum, and ventricular septum describe what congenital heart dz?
atrioventricular septal defects
are AVSDs more common in cats or dogs?
cats
asymptomatic +/- tachypnea/dyspnea or syncope
where is the PMI of the murmur in a cat with AVSD?
left or right parasternal, diastolic, or systolic
T/F: a patient with an AVSD can have CHF or sudden death as a complication
TRUE, no surgical/interventional therapy available
what are the four heart defects make up the tetralogy of fallot (ToF)?
- pulmonic stenosis
- secondary concentric hypertrophy of RV
- overriding aorta
- ventricular septal defect
hypoxemia and polycythemia are a result of what in tetralogy of fallot?
PS > high pressure in RV > R to L shunt (because of ventricular septal defect)
what is the most common cause of cyanotic heart disease in cats and dogs?
tetralogy of fallot (ToF)
what palliative surgical procedure can be done for ToF?
systemic-to-pulmonary anastomosis (modified Blalock-Taussig shunt) > improves pulmonary blood flow and reduces hypoxemia
what is the definitive treatment for ToF?
open-heart repair of VSD and PS
why is complete balloon valvuloplasty not performed in a patient with ToF and only partial done?
it would lead to a large L-to-R shunt
non-selective beta blocker (propanolol) therapy, exercise restriction, phlebotomy (PCV > 65%) and +/- hydroxyurea are all ways to medically manage what congenital defect?
tetralogy of fallot
systolic, low grade (I-III/VI) murmur with the PMI over the aortic/pulmonary valve (left heart base) that disappears by 6 months of age are all criteria to be considered what type of murmur?
innocent heart murmurs
vascular ring anomoly characterized by persistence of the right fourth aortic arch during fetal development describes what congenital defect?
persistent right aortic arch (PRAA)
what congenital defect causes regurgitation in puppies and kittens because the esophagus is entrapped in the “ring”?
PRAA
blood flow from the LA > RA, often low grade murmur, and split S2 are all characteristics of what congenital defect?
atrial septal defect
what might a large ASD result in?
severe pulmonary hypertension > shunt reversal
