Module 15 Wk 1 Flashcards
(222 cards)
(Acquired cardiac diseases in dogs - Valvular problems and Cardiomyopathies)
What is concentric hypertrophy?
Pressure overload where wall grows thicker towards center of heart.
What is eccentric hypertrophy?
Volume overload where wall of heart grows towards the outside
What is MMVD?
Myxomatous mitral valve disease
What kinds of dogs is Myxomatous mitral valve disease most common in?
- Highest prevalence in medium size breeds.
- Older dogs
- Mostly male
- CKCS
Describe what Myxomatous mitral valve disease is?
Changes in the cellular constituents as well as the intercellular matrix of the valve apparatus
In Myxomatous mitral valve disease, what do the changes to the valve lead to?
Irregularity of the valves leads to an inability to close properly and prolapse of LA so Insufficiency/Regurgitation
What are consequences of Myxomatous mitral valve disease?
- There is an increase in left atrial pressure, which leads to left-sided CHF.
The left ventricle is experiencing a volume overload due to the LA accommodating more blood, so the LV has to get bigger to push more blood forward. - Due to pressure being high on the left, it may cause pulmonary hypertension on the right and lead to right-sided CHF as the arteries constrict.
What are the different stages of heart disease?
Stage A: dogs at risk for developing heart disease but no clinical signs or structural changes. Predisposed.
Stage B: structural changes are present
- B1: Clear valvular insufficiency, but no clear cardiac remodelling is present. Valve leaking but heart is not big yet as heart not noticed it yet.
- B2: Clear valvular and cardiac remodelling present. Heart bigger as has noticed it
Stage C: Current or past clinical signs of heart failure. Developed oedema.
Stage D: End-stage, refractory to treatment
T/F a dogs with Myxomatous mitral valve disease (MMVD) is commonly asymptomatic?
True
If there is clinical symptoms of MMVD, what would they be?
- will have a cough is severe L CHF
- dyspnoea
- syncope
- Exercise Intolerance
What should you hear when auscultating a dog with Mitral valve disease?
- Left-sided apical systolic murmur!
- Right side? If very loud or concomitant tricuspid regurgitation
What would you see on radiographs of a dog with mitral valve disease?
congested pulmonary vein, increased left atrial size, elevation of trachea and compression of the left principal bronchus
Cowboy legs tell you L atrium get bigge!!!!!!!
What diagnostic tool confirms mitral valve disease and why?
Echocardiography confirms disease! Mitral valve changes and dilatation of left atrium/ventricle
T/F with mitral valve disease NTproBNP and cradiac troponin I will both increase?
True
What are your treatment options for the different stages of mitral valve disease?
Stage A, B1: nothing
Stage B2: Pimobendan
Stage C: Pimobendan + Diuretics (clinical signs)
What does DCM stand for?
Dilated cardiomyopathy
What is dilated cardiomyopathy?
It is where the muscle cannot pump therefore the heart has to try compensate by stacking more muscles in series leading to volume overload.
What kind of dogs does DCM effect the most?
It mostly affects large/giant breeds of dogs that are often middle-aged/older. Mostly males over females.
What is the difference between primary and secondary DCM?
Primary is when you inherit DCM, whereas secondary is where it mimics DCM, but the heart muscle is not the problem.
What sort of things could cause secondary DCM?
- Arrhythmia- induced
- Metabolic; diabetes, systemic hypertension, hypothyroidism, acromegaly and pheochromocytoma
- Drugs and toxins; chemotherapeutic agents, catecholamines
- Nutrition
- Myocarditis (inflammatory); infectious and non-infectious diseases
Describe DCM with big words babes
The Myocardium is sick leading to systolic Dysfunction. This causes low cardiac output (exercise intolerance) and Cardiac Remodelling stimulus (left eccentric hypertrophy). Resulting in Left (+ right) sided congestive heart failure.
ANDDDD a Sick heart = Arrhythmias = Syncope/Sudden Death.
What would a dogs history be if the had DCM?
- Asymptomatic (occult)
- Exercise intolerance
- Cough (acute congestive heart failure)
- Tachypnoea, Dyspnoea
- Right sided problem: Pleural effusion, ascites
- Syncope
On a clinical exam of a dog with DCM what would you find?
- A low grade murmur or none
- Arrhythmias
- Weak pulse
- Tachycardia
- Prolonged capillary refill time
- Left sided CHF: Dyspnoea
- Right sided CHF: Ascites
diagnostic tests for DCM
- radiographs arent to slay at helping
- biomarkers again are not super slay but can hint to cardiac probs
- ECG good to see arrhythmias as the arrive before cardiac remodelling