Canine Top Cardiac Diseases - Part 3 Flashcards
what breeds are predisposed to HCM?
maine coons & ragdolls - males may be predisposed
what is the classic case presentation of HCM?
usually no murmur/arrhythmia, tachypnea, dyspnea, paraplegia, or monoplegia due to thromboembolism
what is seen on rads of a cat with HCM?
cardiomegaly, dilated left atrium, pulmonary edema, & pleural effusion
what is seen on echo of a cat with HCM?
atrial dilation, left ventricular wall thickening, papillary muscle hypertrophy, systolic anterior motion of the mitral valve, & echo contrast (smoke) in dilated left atrium due to swirling of RBCs
what screening can be done for HCM?
NT-proBNP for occult HCM that is then confirmed with an echo & genetic testing of myosin binding protein C3 for the A31P/A74T mutation in maine coons or the C820T mutation in ragdolls
what treatment is used for HCM?
for CHF, O2 therapy, loop diuretics, pimobendan, ace inhibitors, b-blockers if left ventricular outflow obstruction on echo
what in hospital treatment is used for prevention of thromboembolism in cats with HCM?
anticoagulant heparin, analgesia, & CHF treatment
what at home treatment can be used for preventing thromboembolisms in cats with HCM?
clopidogrel to prevent thromboembolism & enoxaparin to treat thromboembolism
what does the prognosis of HCM depend on?
the presentation, severity of disease, & response to treatment
what seen on an echo puts a cat with HCM at rick of a thromboembolism?
evidence of echo contrast in dilated left atrium
what genetic testing is done for HCM?
maine coon & ragdoll cats - don’t breed homozygous cats
T/F: decompensated cats with CHF are often hypothermic on presentation
TRUE
what are the top 3 heart block patterns seen?
2nd degree, 3rd degree, & sick sinus syndrome
what clinical signs are seen with 2nd degree av block?
only seen with high grade - exercise intolerance & syncope
what clinical signs are seen with 3rd degree av block?
dogs - syncope cats - rarely have clinical signs
what clinical signs are seen with sick sinus syndrome?
clinical signs are due to severe bradycardia, sinoatrial arrest, or tachycardia - exercise intolerance & syncope
what is the breed predilection for sick sinus syndrome?
mini schnauzers, westies, & cockers
what are the 3 main types of 2nd degree block?
mobitz type I, mobitz type II, & high grade
what is seen on ecg for 2nd degree mobitz type I block?
successive prolongation of P-R interval until a QRS is absent
what is seen on ecg for 2nd degree mobitz type II block?
fixed p-r interval
what is seen on high grade 2nd degree av block?
many p waves are not conducted
how is 2nd degree block diagnosed?
ecg - look for an occasional unconducted atrial beat, one or more p waves not followed by a QRS complex, but otherwise normal p waves & QRS complexes
what is seen on ecg/holter monitor of 3rd degree block?
complete dissociation of atrial/ventricular activity & no relationship between the p wave & QRS complex
what is seen on ecg/holter monitor of sick sinus syndrome
sinus bradycardia alone, sinus rhythm with long inappropriate pauses (sinoatrial arrest) between p-qrs complexes, +/- varying tachycardia (brady-tachy syndrome)
what may be seen on echo for 2nd degree block, 3rd degree block, & sick sinus syndrome?
look for any structural disease to explain arrhythmias & assess heart changes secondary to bradycardia including chamber enlargement or valvular insufficiency
what is the purpose of using an atropine response test on a dog with sick sinus syndrome?
to determine whether it is physiologic (positive response) or pathologic (no change)
what treatment is indicated for 2nd degree block?
theophylline (sympathomimetic), terbutaline (sympathomimetic), or propantheline (parasympatholytic) - pacemaker if high grade
what treatment is indicated for 3rd degree block?
pacemaker
what treatment is indicated for sick sinus syndrome?
bradyarrhythmias - sympathomimetic or parasympatholytic, pacemaker, for brady-tachy syndrome address bradyarrhythmia as meds to control tachycardia can worsen the bradycardia
T/F: for sick sinus syndrome & 2nd degree heart block, medication is only indicated if bradycardia is causing clinical signs
TRUE
why should 3rd degree heart block always be treated?
there is a risk of sudden death
what are the top 5 congenital cardiac conditions?
PDA, subaortic stenosis, pulmonic stenosis, atrial or ventricular septal defects, & teralogy of fallot
what are the breed predilections for PDA?
poodles, chi chi, maltese, bichon, poms, GSD, labs, & newfoundlands
what is the classical clinical presentation of PDA?
continuous left base washing machine murmur - females usually affected more than males
what is the classical clinical presentation of reverse PDA?
cyanotic mucus membranes in caudal body (vulva/prepuce) with pink gingiva & absence of the washing machine murmur
what is the breed predilection for pulmonic stenosis?
frenchies, english bulldogs, labs, beagles, samoyeds, & cocker spaniels
what is the classic case presentation of pulmonic stenosis?
systolic left base murmur
what is the breed predilection for subaortic stenosis?
goldens, rotties, mastiffs, newfoundlands, boxers, german shepherds
what is the classic case presentation of subaortic stenosis?
systolic left base murmur that may be auscultable at the thoracic inlet
what is the breed predilection of ASD/VSD?
for ASD - english springer spaniel
what is the cliassic case presentation of ASD/VSD?
ASD - typically no murmur VSD - possible right thoracic systolic murmur
what is the breed predilection for tetralogy of fallot?
english bulldogs, samoyeds, keeshonds, & terriers
what is the classic case presentation of tetralogy of fallot?
exercise intolerance, syncope, left systolic murmur, differential cyanosis (mucus membranes in caudal half of body more cyanotic)
what is the etiology of reverse PDA?
severe pulmonary hypertension exceeds the systemic pressure causing blood to flow from right to left through the ductus, the caudal body becomes hypoxic, & renal perfusion with hypoxemic blood causes the release of erythropoietin resulting in polycythemia
what is the etiology of PDA?
persistent patenty of fetal ductus arteriosus after birth
what is seen on radiographs of a dog with a PDA? what about echo?
rads - left atrial/ventricular enlargement, distinct pulmonary artery & descending aorta, ductus bulge echo - variable left atrial/ventricular dilation, continuous turbulent blood flow in pulmonary artery, & visible ductus emptying into the pulmonary artery
what is seen on radiographs of a dog with SAS? what about echo?
rads - prominent ascending aortic bulge & left ventricular enlargement echo - turbulent high velocity doppler flow through the aortic valve, subvalvular narrowing of the left outflow tract due to a band of tissue, & varying left ventricular hypertrophy
what is seen on rads of a dog with PS? what about echo?
rads - right cardiomegaly & main pulmonary artery bulge echo - high velocity outflow past pulmonary valve, irregular/stenotic pulmonic valves, post-stenotic dilation of the pulmonary artery, pulmonic insufficiency, varying right ventricular hypertrophy/dilation - english bulldogs may have concurrent pulmonary artery abnormalities
what is seen on rads of a dog with ASD/VSD? what about echo?
rads for asd - dilated pulmonary artery & right ventricular dilation rads for vsd - dilated pulmonary artery & left atrial/ventricular dilation echo - visualization of the septal defect
what is seen on a CBC from a dog with tetralogy of fallot?
polycythemia secondary to chronic hypoxia!!
what are the 4 cardinal signs of tetralogy of fallot on echo?
interventricular septal defect, pulmonic stenosis, right ventricular hypertrophy, & over-riding aorta
what treatment is indicated for a reverse PDA?
no occlusion!!!!! phlebotomy to treat polycythemia
what treatment is indicated for a PDA?
surgical ligation (thoracotomy), minimaly invasive transarterial occlusion, transarterial coil, & manage CHF is present
what is the treatment used for SAS?
atenolol to decrease the risks of arrhythmias - intervention/surgery isn’t successful
what is the treatment used for PS?
percutaneous balloon valvuloplasty if severe & in english bulldogs, concurrent pulmonary artery anomalies/aberrant carotid artery bands make intervention tricky
what is the treatment used for ASD/VSD?
small defect - no treatment large defect - patch graft repair (not commonly done for ASD), & for vsd - amlodipine for aterial vasodilation to reduce afterload
what is the treatment used for teralogy of fallot?
b-blockers, therapeutic phlebotomy if erythrocytosis, & no good surgical/intervention available
what is an innocent murmur?
soft murmur before 16 weeks of age in an asymptomatic puppy that should be reassessed after 16 weeks
what is the prognosis for PDA?
with repair, good, without repair, guarged to poor prognosis as it will progress to CHF
what is the prognosis of SAS?
mild to moderate - dogs can live a normal life & severe - poor long term, average life span of 3 years
what is the prognosis of PS?
mild to moderate, normal lives, severe - if successful balloon valvuloplasty can be normal, but if unsuccessful/not possible, guarded to poor long term
what is the prognosis of ASD/VSD?
small defects is good & large defect is guarded
what is the prognosis of teralogy of fallot?
death at a young age is common in animals that are hemodynamically affected by the defects
what is the breed predilection of endocarditis?
dogs over 4 years - GSD, labs, boxers, dobermans - may have concurrent congenital heart disease (SAS/mitral dysplasia)
what is the classic case presentation of endocarditis?
signs of systemic illness (lethargy, anorexia, weakness), intermittent lameness, fever, & signs of CHF (cough, tachypnea, dyspnea) - approximately 26% don’t have a murmur
what are the bacterias that can cause endocarditis?
strep, staph, klebsiella, e coli, & bartonella
what is seen on echo of a dog with endocarditis?
thickened hyperechoic valve, pedunculated mass on valve leaflet, +/- secondary chamber dilation
what is seen on cbc, chem, urinalysis, & blood/urine cultures in a dog with endocarditis?
CBC - leukocytosis, anemia, thrombocytopenia, chem - azotemia urinalysis - proteinuria & cultures for listed bacterias
what treatment is used for endocarditis?
antibiotics for 2-3 months ideally based on culture/testing, broad spectrum (ampicillin/amoxicillin, cephalosporin combined with fluorinated quinolone - cidal drugs are best), for bartonella - combo of fluorinated quinolone & doxycycline, & treat for CHF (oxygen, furosemide, pimobendan)
how is bartonellosis causing endocarditis prevented?
flea control
what is the prognosis of endocarditis involving the mitral valve? what about the aortic?
mitral valve is more favorable than aortic valve
T/F: a new murmur, especially a diastolic one, in a systemically ill dog should prompt evaluation for endocarditis
TRUE
T/F: there is no specific treatment for valve damage & secondary valvular insufficiency from endocarditis
TRUE
