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69 Cards in this Set
- Front
- Back
What are the major mediators of Ca release in vascular musculature?
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Norepinephrine
Angiotensin II Endothelin I ADH (a little bit of Ca induced Ca release via ryanodine receptor) |
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Describe how smooth muscle contractions occur.
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Ca released (via activity of ligand-induced 2' messengers),
Ca binds to calmodulin, Ca/calmodulin activates myosin light chain kinase (MLCK) MLCK phosphorylates myosin light chain, allowing myosin to interact with actin leading to CONTRACTION |
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Which of the following cause vascular constriction?
a) RHO kinase pathway b) NO c) NE d) cGMP e) bradykinin |
a) RHO kinase pathway
c) NE (also ATII, ET-1, ADH, and Ca) |
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Which of the following cause vascular dilation?
a) RHO kinase pathway b) NO c) Epinephrine d) cAMP e) bradykinin |
b) NO
c) NE e) bradykinin (also adenosine) |
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T or F:
NO causes increases in cGMP which directly suppresses MLCK. |
True!
This causes relaxation (vasodilation) |
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Pulmonary hypertension occurs when mean pulmonary pressure exceeds ___mm Hg.
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>25mmHg
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What three mechanisms can cause pulmonary hypertension?
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Lumenal narrowing of pulmonary vasculature
Increased pulmonary blood flow Increased blood viscosity |
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What increases pulmonary vascular resistance?
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Vasoconstriction
Vascular remodeling Pulmonary thrombosis/fibrosis |
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Which murmurs are congruent with pulmonary hypertension?
a) split S2 b) S3 gallop c) systolic murmur on R side d) systolic murmur on L side |
a) split S2
c) systolic murmur on R side (indicative of Tricuspid Regurg; also should hear pulmonary crackles if there is significant pulmonary dz) |
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What are the three major pathways that can be manipulated when treating pulmonary hypertension?
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Prostacyclin-cAMP pathway
NO pathway Endothelin pathway |
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What are the phosphodiesterase inhibitors available to treat pulmonary hypertension?
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Sildenafil (viagra)
Pimobendan |
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Which animal has the most reactive pulmonary vasculature? The least?
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Horses>Cats >> Dogs
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What is the gold standard diagnostic for pulmonary hypertension?
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Cardiac cath
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What are the factors contributing to blood pressure?
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Total peripheral resistance
Heart rate Preload, contractility, afterload |
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Tissues usually autoregulate blood pressure between which two values?
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70 and 170mmHg
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What are major causes of systemic hypertension in dogs?
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Renal dz
Cushing's Pheochromocytoma Diabetes Mellitus Hyperaldostronism |
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What are major causes of systemic hypertension in cats?
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Hyperthyroidism
Renal dz |
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What 4 major systems say OUCH to hypertension?
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Ocular
Urinary (kidney) CNS (brain) Heart (cardiovascular) |
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What cardiovascular effects does systemic hypertension cause?
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LV hypertrophy
Diastolic dysfunction Systolic murmur (RVOT obstruction) |
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What are the three main areas of pharmacologic hypertension treatment?
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Reduce hypertension
Adrenergic blockade Diuretics |
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Which drugs are commonly used with systemic hypertension? Which is good for hyperthyroid cats?
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Amlodipine (Ca channel blocker)
Atenolol (beta blocker; good for hyper-T cats) Maybe throw diuretics on there... |
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T or F:
Valvular heart disease is the most common in dogs <30lbs. |
True
|
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What structures constitute the mitral apparatus?
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Valve leaflets (anterior and posterior)
Chordae tendinae Papillary muscles Annulus fibrosus |
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How does valvular histology differ between the atrial and ventricular sides of the valve?
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Atrial side (loose CT; spongiosa)
Ventricular side (thick CT; fibrosa) |
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Fill in the blanks for valvular lesion distribution in dogs:
62% _________ valve alone 32.5% _______ and ________ 2.5% ________and_________ 1.5% ________ valve alone |
62% mitral valve alone
32.5% mitral and tricuspid 2.5% mitral and aortic 1.5% tricuspid valve alone |
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What best describes the pathogenesis of valvular disease?
a) fibromatous degeneration b) endothelial damage c) collagenolytic degeneration d) myxomatous degeneration |
d) myxomatous degeneration
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What are the 3 determinants of mitral regurgitant volume?
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Regurgitant orifice area
LV/LA pressure gradient Duration of systole |
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Regarding heart diseases in dogs, if you can pick the dog up, it probably has __________ while if you can't pick it up, it has ___________.
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Valvular in small; DCM in large
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Which drug has the most effect at reducing regurgitant volume?
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Pimobendan is the PIMP
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Put the following murmurs in the correct order of progression in valvular disease.
a) Systolic murmur + gallop b) Systolic click/plateau c) musical murmur d) holosystolic murmur |
b) Systolic click/plateau
c) musical murmur d) holosystolic murmur a) Systolic murmur + gallop (bad news) |
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Besides murmurs, what will likely be found on a physical exam of a dog with valvular disease?
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Jugular venous distension, organomegaly
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What parameter is most predictive of valvular disease prognosis in color flow doppler?
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Jet diameter
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What is probably the best diagnostic tool in diagnosing valvular heart disease?
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Thoracic rads! (will see LA enlargement or biventricular enlargement and can also track efficacy of diuresis)
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How is acute congestive heart failure treated?
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FON + pimobendan or hydralazine
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How is chronic congestive heart failure treated?
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Diuretics
RAAS inhibition (ACE inhibitor +/- ALD antagonist) Positive inotrope/inodilator |
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How is mild degenerative valvular disease treated?
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Diuretics
RAAS inhibition |
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What are the major complications in valvular disease?
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A-fib/supraventricular tachy
Ruptured chordae tendineae Pulmonary hypertension Left atrial tears |
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Left atrial tears with valvular disease is more common in...
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...male Dachshunds
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How is a-fib in valvular disease treated?
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Digoxin + Ca blocker (dilacor)
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How is valvular disease treated surgically in dogs?
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Not really surger-ized...mostly only in humans!
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What is the most common congenital heart defect of horses?
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VSD
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T or F:
It is normal for a foal to have a continuous murmur its first week of life. |
True! PDA!!!
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Which valves are commonly affected in equine valvular disease?
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Aortic and mitral
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What 2 drugs are commonly used for horses in heart failure?
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Digoxin
Furosemide |
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What is the best known pathologic rhythm in horses?
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a-fib
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How is a-fib treated in horses?
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If <60bpm, convert to sinus rhythm w/quinidine
If >60bpm, treat CHF and reduce ventricular rate w/digoxin |
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Which of the following are potential side effects of quinidine therapy in horses?
a) nasal mucosal edema b) hypertension c) colic d) laminitis e) bog spavin |
a) nasal mucosal edema
c) colic d) laminitis (also depression, urticaria, hypotension) |
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What is the most common cause of a-fib in cattle?
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GI DISEASE
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What is weird about camelids and endocarditis?
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it affects the mural endocardium of the ventricles
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What is the most common region to find endocarditis in dogs? What other animals have this predisposition?
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AORTIC AND MITRAL VALVES (same with cats, horses and pigs)
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Where is endocarditis mostly found in ruminants?
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tricuspid and pulmonic valves
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T or F:
Cattle are speedball freaks. |
True!
They get R sided heart endocarditis just like heroin junkies! |
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Which of the following are involved in the pathophysiology of endocarditis?
a) valvular insufficiency b) valvular stenosis c) thromboembolism d) arrthymias |
a) valvular insufficiency
c) thromboembolism d) arrthymias (also sepsis and immune mediated dz) |
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What are target organs for endocarditis thromboemboli?
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Spleen>Kidney>Brain>Heart>Joints
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What are the usual isolates for endocarditis in cattle? Horses? Dogs?
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Cattle (Corynebacterium)
Horses (Strep) Dogs (any - E. coli/Strep/Staph) |
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"Culture-negative" endocarditis in dogs is usually due to...
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..Bartonella
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Which of the following are MAJOR criteria of endocarditis diagnosis?
a) fever b) positive blood culture c) recent onset of a systolic murmur d) large breed dog e) valve lesion detected by US |
b) positive blood culture
e) valve lesion detected by US (also recent onset of DIASTOLIC murmur) |
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T or F:
Dental disease greatly raises the risk of endocarditis in small dogs. |
False! Prevalence is still pretty low!
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Which antibiotics are typically used in treating endocarditis?
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Cephalosporin + Amakacin or Enrofloxacin
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How long does the complete life cycle of D. immitis last? How long can adults live in dogs?
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7-9 month cycle
5-7 yr lifespan |
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How long after infection does it take D. immitis to reach sexual maturity? How long can microfilaria live in the dog bloodstream?
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120d for maturity
2 yrs for microfilariae |
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What are some causes of false negatives in heartworm serology?
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Immature female worms
Low worm burden Single-sex male infxn Improper test kit handling True occult infection |
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What are the types of D. immitis testing?
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Antigen (ELISA)
Antibody Microfilariae tests (Knott, direct, hematocrit, filter blood) |
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What do heartworms look like on echo?
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=
like equal sign |
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What drug is best for an adulticide for D. immitis infection?
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Melarsomine
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Concurrent infection with _____________ may play a part in pathogenesis of heartworm disease.
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Wolbachia
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Which prophylactic macrolide has the most microfilariocide activity?
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Milbemycin (interceptor/sentinel)
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What are signs of caval syndrome?
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dirofilarial hemoglobinuria (mechanical hemolysis)
pulmonary hypertension effects on left sided cardiac structures |
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What are some other heartworm sequelae?
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Cor pulmonale
Immune-mediated glomerulonephritis Pulmonary eosinophilic infiltrates Eosinophilic granulomas |