Acquired Heart Disease: Valvular Flashcards
Chr. degenerative valvular disease (endocardiosis)
Most common acquired cardiac dz in dogs
Non-inflammatory myxomatous degeneration (collagen disorder, fibroelastic tissue replacement)
Which valve is endocardiosis most common?
Mitral valve
Then tricuspid, aortic then pulmonic (+ chordae tendineae)
___________ breeds are at an increased risk for endocardiosis
Chondrodystrophic (short-legged dogs)
Other names for mitral valve dz
Chronic degenerative valve dz
Degenerative valve dz
Endocardiosis of the mitral valve
Myxomatous degeneration of the mitral valve
Mitral valve function
Allows blood to flow from the left atrium to the left ventricle during diastole
Prevents blood from flowing back into atrium during systole
Mitral valve leakage
Mitral regurgitation/ mitral insufficiency
Leaking blood from ventricle through MV into atrium during systole —> systolic heart murmur
What causes MR?
Abnorms of the valve leaflets (CDVD*, dysplasia and bacterial endocarditis)
Abnorms of the chordae tendinae (CDVD and dysplasia)
Valve annulus dilation (ventricular dilation)
Abnorms of papillary muscles (maloreintation and dysplasia)
Degenerative lesions of MR
Thickening of valve leaflets
Nodular thickening of leaflet margins
Weakening and lengthening of chordae
Pathophysiology of endocardiosis
Volume overload of heart
Reduced forward SV → Na/ H20 retention
Systolic pump failure (rare, chr.)
Decompensation of stable CDVD patient
Progression of MR (over years)
Mitral valve prolapse (+/- systolic click)→
Mild mitral valve regurg →
Moderate MR →
Servere MR (+/- mumur on PEc)
The end result of CDVD is ______________
LCHF (pulm. edema)
Myocardial failure, pulm. hypertension and arrhythmias
Predisposed signalments of CDVD
Small breeds, middle aged to geriatric
Cavalier King Spaniels
Mini/toy poodles (mixed with poo in name)
Presenting complaint of CDVD
Incidental finding (murmur with no CS) OR
Coughing, resp. distress, weakness, leth and exercise intolerance, syncope
CDVD dx
ECG: wide P waves (LA enlargement) and tall R waves (LV enlargement)
Clin path associated with endocardiosis
Pre-renal azotemia
↓ Na, K, and Cl (if severe)
International small animal cardiac health council heart failure classification (ISAHCH)
Class 1: asymptomatic (no CS with heart dz)
Class 2: Mild to mod heart failure (coughing, exercise intolerance, tachypnea and mild distress)
Class 3: Advanced heart failure (exercise intolerance, resp. distress, ascites, cardiogenic shock)
ACVIM cardiology group consensus classification (A)
Identifies high risk patients but no current structural dz
ACVIM cardiology group consensus classification (B)
Asymptomatic patients with structural heart dz
B1: no mild radiographic/ echo changes
B2: structural change (pimobendan)
ACVIM cardiology group consensus classification (C)
Past or current CS of heart failure associated with structural heart dz
Acute (furosemide, O2, pimobendan, dobutamine infusion) or chr. (furosemide, ACE inhibitor, pimobendan)
ACVIM cardiology group consensus classification (D)
End-stage refractory to “standard therapy”
Acute or chr.
Tx: left atrial decompression
VLAS __________ suggests LAE
> 2.3
MV surgical repair
Open heart sx with bypass → RA approach, chordae replacement, double annuloplasty
Recover 7d in hospital
Transcatheter edge to edge repair (mitral clip)
Hybrid procedure requires sx approach to apex and interventional cardiologist to deliver device
Clips pull middle leaflets together
When is mitral clip considered?
Dogs in stage C and D
King Charles earlier in stage B2
What causes decompensation
- Chordinae tendinae rupture
- Increased salt
- Atrial tear
- Arrhythmia
Endocardiosis prognosis
Months to 2 years once heart failure develops
Normal life with no or few CS
Infectious endocarditis
Inflammatory destructive lesion of valve
Endothelial damage with fibrin deposition
Vegetation induces valvular dysfunction
Risk factors of infectious endocarditis
Pre-existing valvular damage (congen cardiac dz)
Source of bacteremia
What valaves are involved in infectious endocarditis?
Mitral, aortic and mural endocarditis
Pathophysiology of infectious Endocarditis
L-CHF
Arrhythmias (ven. tachyarrhythmias and AV block)
Systemic septic emboli (can cause death)
Vegetative lesion (fibrin, inflamm cells)
Myocardial abscesses
Aortic sinus rupture/ fistulae
Signalment of infectious endocarditis
Any age
Large breeds, male predominance
CS of infectious endocarditis
Systemically ill, febrile, leth and shocky
Cough, dyspnea, exercise intolerance
Swollen hot painful joints, abdominal pain, CNS signs
Syncopal episodes
Cardiac ausculatations for infectious endocarditis
S3 gallop
Crackles/ wheezes if pulm. edema/ pulm abscesses
Femoral pulses of infectious endocarditis
Pulse deficits
Hyperkinetic
Most common organisms causing infectious endocarditis
Corynebacterium spp
Streptococcus spp.
Staphylococcus spp.
Clinical management of infectious endocarditis
Antibiotic therapy: bacteriocidal or
Empirical (aminoglycoside, penicillin)
2-6w of therapy
