Cardio - DMVD Flashcards
What is the most common heart disease in dogs?
Degenerative Mitral Valve Disease (DMVD)
What is DMVD?
Progressive, age-related degeneration of the heart valves that results in valve regurgitation, progressive heart dilation, and ultimately results in CHF.
What valves are most commonly to least commonly affected in DMVD?
Mitral > tricuspid > aortic >> pulmonic (dogs)
What are some other names for DMVD?
Degenerative Valve Disease (DVD)
Myxomatous Mitral Valve Disease (MMVD)
Chronic Valvular Heart Disease (CVHD)
Endocardiosis
What is the etiology of DVMD?
- Myxomatous degenerative valve apparatus changes
- Thickening of valve and chordae tendinae
- Regurgitation
Valvular regurgitation is a _____ overload disease.
volume
What pathophysiology is caused by DMVD?
- Valvular regurgitation is a volume overload disease
- Excess volume in the ventricle results in eccentric hypertrophy and dilation
- Complications of progressive disease: L-CHF, arrhythmias, atrial rupture
What is the common signalment for DMVD?
Dogs (more common) and horses, middle aged to older, male > female;
Small-medium sized dogs more common
Breeds: CKCS, mini poodle, Schanuzers, Fox terriers, Pomeranian, Yorkie, Chihuahua, Dachshund
What happens in stage A of HF?
At risk breeds and/or signalment with no murmur
What happens in stage B1 of HF?
Degenerative valve changes –> regurgitation and a murmur (L apical systolic regurgitant) with normal heart size or mild L atrial dilation
What happens in stage B2 of HF?
Murmur with moderate or severe LA dilation
What happens in stage C of HF?
Progression to CHF, can have concurrent arrhythmias and/or multiple episodes of CHF
(Heart dilated, fluid starting to back up into lungs)
What happens in stage D of HF?
Episode of CHF that is refractory to tx
What is the presentation of stage A?
Asymptomatic, no murmur
What is the presentation of stage B1?
Asymptomatic, murmur and/or mid-systolic click, normal rads or mild LA dilation
What is the presentation of stage B2?
Asymptomatic or symptoms of cough, exercise intolerance;
Murmur with moderate-severe LA dilation on rads
What is the presentation of stage C?
Signs of CHF - soft cough, increased RR and effort, weakness, exercise intolerance, collapse, restlessness at night, weight loss, reduced appetite;
Murmur, tachycardia, crackles, +/- arrhythmia and/or pulse deficits;
Moderate-severe L cardiomegaly and pulmonary edema on rads
What is the presentation of stage D?
Same as stage C often with cachexia and/or hypotension;
Tx requires hospitalization and more advanced CHF therapies
What diagnostics can be done in GP to assess HF/DMVD?
Thoracic rads, BP, +/- labs (chem, U/A, NT-proBNP), +/- echo, +/- ECG
What stage of DMVD is shown here?
Appears normal due to normal silhouette but is stage B1
(may sometimes have mild LA dilation)
What stage of DMVD is shown here?
B2 - moderate LA enlargement
What stage of DMVD is shown here?
C;
Moderate to severe LA dilation, pulmonary venous dilation, interstitial to alveolar pattern
What is the definitive diagnostic for DMVD?
Echocardiogram
What echo findings are consistent with stage B1 DMVD?
Thickened valve leaflets with mitral regurgitation
Normal heart size or mild LA dilation
What echo findings are consistent with stage B2 of DMVD?
Eccentric hypertrphy that appears as dilated LA and LV with normal wall thickness
Thickened valve leaflets with regurgitation
+/- valve prolapse or ruptured chordae tendinae
What echo findings are consistent with stage C DMVD?
Same as B2; +/- systolic dysfunction (and end-stage finding in volume overload disease)
What stage of DMVD does this image show? (Would also see “party colors” when the doppler is shown)
Stage B2;
2 leaflets and thickened/nodular/lumpy, open mitral valve, LA dilation, LV dilation
What is relative systemic hypertension?
When a BP is WNL but unacceptably high in the context of a given heart disease
What is the goal in regards to BP in dogs with moderate to severe DMVD?
To maintain it in the low-normal range (~100 mmHg) without signs of hypotension at home (GI upset, weakness, lethargy, collapse)
What stages of DMVD commonly have hypotension? What are the clinical signs? What is the treatment?
Stage C or more commonly stage D;
Cardiogenic shock with low BP;
Tx = positive inotropes (dobutamine)
What is the normal BP of the LA?
8-10 mmHg
What is the normal BP of the aorta?
120 mmHg
What would you be looking for in a chemistry or U/A?
Renal and electrolyte abnormalities
What can serial monitoring with NT-proBNP show?
A progressive increase in NT-proBNP with progressive heart dilation
If a patient has LA enlargement, what would the ECG show?
Wide P wave (P-mitrale)
If a patient has LV enlargement, what would the ECG show?
Tall R wave, wide QRS
What arrhythmias would an ECG show if the origin was ventricular?
Ventricular premature beats or ventricular tachycardia
What arrhythmias would an ECG show if the origin was supraventricular?
Sinus tachycardia, supraventricular premature beats, atrial fibrillation
What medications and follow up would you recommend for a patient with stage A DMVD?
No meds;
CE and exam q 6-12 months to monitor for murmur development
What medications and follow up would you recommend for a patient with stage B1 DMVD?
Antihypertensives if indicated by BP;
Exam, rads, BP, +/- NT-proBNP q 6-12 months
RRR at home
What is the prognosis for a patient in stage B1?
Good
What medications and follow up would you recommend for a patient with stage B2 DMVD?
Pimobendan, +/- ACEi, +/- antihypertensives;
Exam, thoracic rads, BP, +/- NT-proBNP q 6-12 months
RRR at home
Dietary Na restriction
What is the prognosis for a patient in stage B2?
Good to fair
What medications and follow up would you recommend for a patient with stage C DMVD?
Meds = diuretic (furosemide, spironolactone), ACEi, Pimobendan, +/- anti-arrhythmic, +/- antihypertensive (amlodipine);
Exam, thoracic rads, BP, chemistry, +/- NT-proBNP q 6 months or sooner if signs of CHF or renal disease
RRR at home
Dietary Na restriction
What is the prognosis for a patient in stage C?
Guarded (average 1-2 years survival after first episode of CHF)
What medications and follow up would you recommend for a patient with stage D DMVD?
Meds = diuretic (furosemide, spironolactone, hydrochlorothiazide), ACEi, Pimobendan
Hospitalization with frequent monitoring of vitals and BP
RRR daily
Dietary Na restriction
What is the prognosis for a patient in stage D?
Guarded to poor
