Sa Medicine Ii -- Acquired Valvular Disease

Front 1

Mitral valve apparatus comprises?

Back 1

-- valve leaflets

-- chordae tendineae

-- annulus fibrosis

-- papillary muscles

-- LA and LV walls

Front 2

What are the four histologic layers of the leaftlet?

Back 2

-- atrialis
(Endomyocardium: thin, endocardial cells)

-- spongiosa
(fibroblasts, loose collagen, ground substance)

-- fibrosa
(denser, organized collagen fibers)

-- ventricularis
(endothelium)

Front 3

Chronic degenerative valve disease pathophysiology (myxomatosis degeneration)? Which layers of the leaflet are the most affected?

Back 3

--degeneration of the fibrosa

>> collagen and elastin dissolution/disorg.

--thickened spongiosa

>> hyaluronic acid, chondroitin sulfate accumulations

--endothelial damage

--hemorrhage, edema

Front 4

Etiology of CDVD? Pathology of CDVD?

Back 4

--etiology: unknown, likely multifactorial

>> genetic component

--pathology: focal lesion >> multinodular lesion >> club-like leaflets that curl onto themselves worse at leaflet tips

Front 5

CDVD is associated with prior infection or bacteremia. T/F?

Back 5

--false, it is NOT associated with prior infections or bacteremia.

Front 6

CDCD progression?

Back 6

-- valve degeneration >> valvular insufficiency >> LA dilatation, LV eccentric hypertrophy >> annular dilatation, papillary misalignment >> more valve degeneration and insufficiency

>> becomes vicious cycle

Front 7

Determinants of regurgitant volume?

Back 7

1. regurgitant orifice area (size)

2. LV-LA pressure gradient
>> MR is worse, higher pressure

3. Duration of systole

Front 8

Pathophysiology of regurgitation due to CDVD?

Back 8

-- decreased SV (some went back into LA)

-- hypoperfusion

-- inc. RAAS

>> inc. blood vol. (preload)

>> normalized SV

>> worsened mitral regurgitation

>> LV eccentric hypertrophy

--inc. pulmonary capillary wedge pressure

>> CHF (LHF)

Front 9

Signalment of dogs with CDVD?

Back 9

--small breed

>> min pins/schnauzers, chihuahuas, dachshunds

--older age

--male

Front 10

History and physical exam findings in dogs with CDVD?

Back 10

-- cough, crackles

-- tachypnea or dyspnea

-- exercise intolerance

-- left apical systolic murmur +/- systolic click

-- +/- right side systolic murmur

-- S3 gallop

-- arrhythmias

-- HR, inc. resp. rate and effort

-- RHF (ascites, jug. distention, hepatomegaly)

Front 11

ECG findings of dogs with CDVD may include?

Back 11

-- sinus rhythm or sinus tachycardia

-- left atrial enlargement (wide P waves)

-- atrial premature contractions (atrial stretch)

-- atrial fibrillation

-- LV enlargement

-- LBBB

Front 12

Three hallmarks of cardiogenic pulmonary edema?

Back 12

-- left atrial enlargement

-- pulmonary venous distension

-- interstitial or alveolar lung pattern

Front 13

Radiographic monitoring of CDVD: what are you looking at?

Back 13

--vertebral heart score

-- VHS increases slowly in early disease

>> inc. markedly in later stages

Front 14

Thoracic radiographs may show?

Back 14

-- trachea parallel to spine

-- left atrial enlargement

-- pulmonary venous distension

-- interstitial/alveolar lung pattern

>> pulmonary edema

-- biventricular enlargement

Front 15

Coughing in small breed male dog may also be due to?

Back 15

--respiratory disease, e.g. tracheal collapse

Front 16

Echocardiography diagnosis of CDVD?

Back 16

--confirm suspected disease

--quantify severeity of regurg.

--assess LV and LA chamber sizes

--assess LV function

--estimate LA/pulmonary venous pressure

--assess for concurrent diseases

--must diagnose heart failure on radiographs

Front 17

Treatment of CDVD?

Back 17

--treat acute HF

>> furosemide, O2, nitroprusside, pimobendan

Front 18

What does nitroprusside do?

Back 18

-- afterload reduction

Front 19

What does pimobendan do?

Back 19

-- vasodilator

-- + inotrope

Front 20

Chronic therapy for decompensated CDVD?

Back 20

-- furosemide

-- enalapril (ACE inhibitor)

-- pimobendan
>> inc. survival, exercise intolerance, symptoms

Front 21

Understand the therapeutics used to treat mitral and tricuspid insufficiency (i.e. why is preload reduction beneficial? Why are ACEi indicated in heart failure?)

Back 21

ACE inhibitors reduce preload, which will decrease systolic dysfunction because you decrease the volume of blood that needs to be pumped (heart workload).

Front 22

Prognosis of CDVD?

Back 22

-- progression of CDVD can be slow

>> may have a murmur for years before development of CHF

--once CHF develops, most dogs will live 1y

>> with treatment

>> shortened prognosis with complications

Front 23

Complications of CDVD?

Back 23

-- atrial fibrillation

-- ruptured chordae tendineae

-- left atrial tear

-- pulmonary hypertension

Front 24

Pathogenesis of atrial fibrillation? Treatment?

Back 24

-- loss of atrial kick >> dec. CO

-- therapy: digoxin +/- diltiazem

Front 25

Pathogenesis of ruptured chordae tendineae?

Back 25

Massive increase in LA pressure

>> inc. pressure in pulmonary vv. and capillaries

-- sudden onset

-- acute pulmonary edema

-- acute dyspnea, collapse, cyanosis

-- variable murmur

-- sudden death

Front 26

Treatment of ruptured chordae tendineae?

Back 26

-- nitroprusside >> afterload reduction

>> reduce systemic pressure

>> reduce pressure that LV must generate

>> reduce pressure gradient between LA & LV

>> dec. regurgitation

Front 27

Left atrial tear outcomes?

Back 27

-- sudden death

-- pericardial effusion and thrombus formation

-- occurs with CDVD, chronic mitral regurgitation

Front 28

Clinical signs of left atrial tear?

Back 28

-- collapse, ascites

--weak pulse

--diminished murmur

--sudden death

Front 29

Treatment for left atrial tear?

Back 29

--pericardiocentesis if tamponade

--surgical closure (if continuing to bleed)

--conservative medical management

>> CHF, dec. atrial pressure

Front 30

Signs of pulmonary hypertension?

Back 30

-- exercise intolerance

-- collapse, ascites, syncope

-- right apical murmur

-- concurrent pulmonary disease

Front 31

Treatment of pulmonary hypertension?

Back 31

-- Sildenafil, PDE5 inhibitor

>> pulmonary arterial vasodilator

Front 32

Anesthetizing CDVD patients?

Back 32

--benzodiazepines and opioids

>> great in cardio patients

--avoid alpha-2 agonists, ketamine

--judicious fluid admin.

--likely a better candidate earlier than later

>> CDVD is progressive

Front 33

Chronic degenerative valve disease (CDVD) is also known as?

Back 33

--endocardiosis

--myxomatosis valvular degeneration (MVD)

Front 34

What is the most common acquired heart disease of dogs?

Back 34

-- chronic degenerative valve disease

Front 35

Acquired valve disease makes up ____% of canine cardiac disease.

Back 35

-- 75%

Front 36

Distribution of CDVD lesions?

Back 36

-- mitral valve alone 62.0%

-- mitral and tricuspid 32.5%

-- mitral and aortic 2.5%

-- tricuspid valve alone 1.5%

Front 37

Genetic component breed associations of CDVD?

Back 37

-- Cavalier King Charles Spaniels

-- Dachshunds

Front 38

CDVD: endothelial damage may do what?

Back 38

-- activate and suppress substances involved in cell growth

>> dysregulation ECM >> activated fibroblasts >> collagen growth location wrong

Front 39

CDVD results in?

Back 39

-- increased valve thickness >> incompetence of valve >> insufficiency >> annular dilation >> R/L atrial dilation and eccentric hypertrophy of R/L ventricle