Cardio - Cavanaugh Flashcards
Clinical signs of CHF in dogs and cats stem from what 3 major events?
- Fluid accumulation
- Low BP
- Tissue perfusion from low tissue out put
Dyspnea, tachypnea, lethargy, and syncope are main stay clinical signs of CHF in which species?
Cat
Dyspnea, tachypnea, cough, exercise intolerance, and syncope are mainstay clinical signs of CHF in which species?
Dogs
What are signs leading us to suspect L-CHF in cats?
- Cough (rare)
- Pulmonary effusion
- Pulmonary edema
2 & 3 —> due to draining into left and right atrium
What are some signs leading us to suspect R-CHF in cats?
Diarrhea (if large volume of ascites)
—>abdominal dissension
What are some signs that would lead us to suspect R-CHF in dogs?
- Pleural effusion ONLY (pleura empties into the Ratrium)
2. Diarrhea if large volume of ascites (abdominal distension)
_______ _________ (two words) is a compensatory mechanism in HF to improve cardiac output.
Sinus tachycardia
Why is spironolactone a useful drug?
- It’s a weak diuretic but K+-sparing
- It’s CARDIOPROTECTIVE (anti-fibrotic)
- Use in cases of Addison’s dz
Why would we use an ACE inhibitor?
- To decrease afterload (indirect vasodilator)
- CARDIOPROTECTIVE against myocardial fibrosis
- Combats the effects of CHRONIC RAAS activation
What are adverse effects of ACE inhibitors? When are they contraindicated?
Systemic hypotension;
Contraindicated if Pt is dehydrated or has Renal Dz (or NSAID use)
Name the drug:
Vasodilator (specifically pulmonary arteriodilator) that inhibits phosphodiesterase 5 and is used for pulmonary hypertension
Slidenafil
How would we treat ventricular tachycardia (emergency)?
Lidocaine (2mg/kg for dogs); (0.2 mg/kg for CATS)
How would we manage chronic ventricular tachycardia?
Mexiletine (PO - class 1 Na+ channel blocker)
Sotalol (PO - class 3 K+ channel blocker)
What drug can we us to treat atrial fib, supraventricular tachycardia, and myocardial relax in HCM?
DILTIAZEM: class IV Ca2+ channel blocker (0.1mg/kg IV SLOW over 5 min - in cats and dogs)
Beta blockers are great cardioprotective drugs for decreasing heart rate AND contractility. However, there’s a caveat… what is it?
ONLY give to stable patients!!
Do NOT give if they’re sick and you don’t know the underlying dz, ESPECIALLY if they have ventricular systolic dysfunction!
T or F:
Pertaining to dietary adjustments in Heart Failure, omega-3 FAs, sodium restriction, and protein restriction may be implemented to help improve the condition.
FALSE; everything is correct up until the protein restriction - they need to maintain muscle mass!
Congenital Disease characterized by volume overload (dilated eccentric hypertrophy) to LEFT side of heart.
Left (o2) —> Right (no O2) shunt!
And continuous heart murmur at Lbase - high grade!
—>check left Axillary region
—>left chamber enlargement on thor radiographs
—>turbulent flow into pulmonary artery on echo
PDA! (Dogs)
What would we see with REVERSE PDA? How do we cure it?
Severe pulmonary hypertension; not curable :(
What dog breeds are predisposed/associated with Subaortic stenosis (SAS)?
Large breeds: Goldens Newfies Rotties, Shepherds, Boxers
Concentric pressure overload in dogs with SAS is toward which side of the heart?
Left!
Upon examination of a young, large breed dog, you hear a systolic murmur at the LEFT base of the heart, near the 3-4th intercostal arch. What fits this murmur description?
SAS
In a dog with SAS, what radiographical findings would we expect?
Prominent ascending aorta + LEFT sided cardiomegaly
How do we cure SAS?
Wellll, we dont. There is no cure, but most are asymptomatic and live a normal life span.
Also, atenolol may help.
Concentric pressure overload in dogs with Pulmonic Stenosis goes toward which side of the heart?
RIGHT!
What breeds of dogs are predisposed/associated with pulmonic stenosis?
Terrier, bulldog, chihuahua, labs
Upon examination of a young dog, you hear a systolic murmur at the left base of the heart. Additional, radiographs reveal a PA bulge at 1-2 o’clock. What are these findings consistent with?
Pulmonic stenosis
Cats with ventricular septal defect (VSD) have a defect in the IV septum leading to eccentric volume overload to what 2 locations?
Lungs + LEFT side of heart
Perimembranous region “high”
In cats, what is VSD commonly seen in combination with?
Pulmonary stenosis/pulmonary hypertension
In cats with VSD, what is characteristic of the murmur?
Systolic; the smaller the defect, the LOUDER the murmur…
*no Tx if murmur is loud
Who is predisposed/associated with Tricuspid valve dysplasia?
Cats + labs
What would we see on rads if Tricuspid valve dysplasia is present?
R ventricle and atrium enlarged
In patients with tricuspid valve dysplasia, eccentric volume overload would be to which side of the heart?
RIGHT
In tricuspid valve dysplasia, what would the murmur sound like?
Right-sided APICAL systolic - low grade even with severe dz
What might we see on EKG of a patient with tricuspid valve dysplasia?
Splintered QRS complex (+atrial fib) = 2 Rwaves
What would we expect on rads of a patient with mitral valve dysplasia?
L ventricle and atrium enlarged
What type of murmur would a patient with MVD have?
Left apical systolic
Patients with mitral valve dysplasia would have dilated eccentric volume overload to which side of the heart?
LEFT
If the left ventricle outflow is obstructed in MVD, how do we treat?
Beta blockers
Tetralogy of Fallot; go!
- Pulmonic stenosis
- Secondary concentric hypertrophy of the R ventricle
- Overriding aorta
- Ventricular septal defects
What is the most common cause of cyanotic heart dz in cats and dogs?
Tetralogy of Fallot
What is the most common acquired valvular dz in dogs? What breeds are predisposed?
Degenerative mitral valve dz (DMVD);
Cavalier King Charles spaniels-young!
*otherwise, older/small dogs
What contributes to the valve remodeling in DMVD?
Increased serotonin signaling via accumulation of GAGs, collagen loss, and fibrosis
In DMVD, eccentric dilation volume overload would be toward what side of the heart?
LEFT (atria) and ventricular enlargement
What type of murmur would we hear with DMVD?
Left apical systolic murmur
What stage of DMVD is aka “congestive heart failure stage” = L-CHF?
What else would we see on radiographs?
stage C - we would also see pulmonary edema (left side)
How do we treat stage C DMVD?
Furosemide, pimobendan, ACE inhibitor +/- spironolactone
What type of murmur IS ALWAYS present in DMVD stage C?
LEFT apical SYSTOLIC
What are the clinical signs associated with stage C DMVD?
Increase RR/HR;
Cough;
Syncope;
Exercise intolerance
How do we diagnose DMVD?
Thoracic radiographs (gold standard for L-CHF): RL, LL, DV
- must have:
1. Left sided cardiomegaly (LA enlarged)
2. Interstitial (+alveolar) pulmonary infiltrates—>edema in perihilar area
And MAYBE
3. Enlarged pulmonary veins
Upon diagnosis of DMVD, what BP would we expect?
Systemic hypertension
What is the gold standard for DMVD diagnosis?
Echo !
Risk factors for Endocarditis….
Subaortic Stenosis
Old, male, large dogs
What are some clinical signs that accompany endocarditis?
Kidney: glomerulonephritis + thromboembolic dz
Joints: polyarthritis + lameness
Most common causative agents of endocarditis?
Staph aureus, staph. Intermedius, strep, e.coli, pseudomonas, bartonella
What type of endocarditis has a more grave prognosis?
Aortic (left basilar diastolic murmur) valve
How should we go about treating endocarditis?
Long-term bactericidal antibiotics:
Beta lactams
Describe the hypertrophy in cats with HCM as a response to sarcomeric dysfunction.
Primary concentric cardiomyocyte hypertrophy (wall thickness >6mm) of the LEFT ventricle!
What creates mitral valve regurgitation or outflow obstruction in HCM?
Systolic anterior motion of mitral valve
What would we see on radiographs for a cat with HCM?
Pulmonary edema,
Pleural effusion
What must we rule out before being sure of HCM diagnosis?
Aortic stenosis Systemic hypertension Hyperthyroidism Acromegaly Infiltration Dz (lymphoma)
How can we describe RCM in cats?
Primary DIASTOLIC dysfunction w/structurally normal ventricular wall of the LEFT ventricle;
Atrial dilation is common
What’s the deal with cats and advanced RCM?
They can have SYSTOLIC dysfunction w the diastolic
—> low output HF and CHF
What breed is known for DCM due to 2 genetic mutations (pyruvate 4+NCSU)?
Dobermans
What are the small breed exceptions to DCM? What should we do with them?
Cocker spaniels,
Portuguese Water Dog,
Toy Manchester terrier
- do a taurine diet test on them!
Categorize the myocardial dz:
Primary ventricular systolic dysfunction (dec contractility, inc blood volume), where ventricle dilation occurs secondarily (muscle can’t eject blood out after systole)
DCM (dogs)
What arrhythmias can we see with DCM dogs?
A.fib
VPC
V.tach
Breed disposition of Arrhythmogenic Right Ventricular cardiomyopathy (ARVC)?
Adult boxers
How is type 3 ARVC different from types 1 and 2?
Type 3–>DYSFUNCTION: ventricular diastolic dilation;
Ventricular and supraventricular tachycardia; loss of AV synchrony :(
What are clinical signs associated with ARVC?
Syncope Exercise intolerance (due to ventricular tachycardia) *do 24 hr halter to find
How would we diagnose ARVC by echo?
(Must have a ventricular arrhythmia)
VPC from RIGHT ventricle are UPRIGHT/POSITIVE in Lead II
When are anti-arrhythmic drugs indicated in dogs with ARVC?
Dogs w/ >1000 VPCs a day!
Sotalol: class III anti-arrhythmic is 1st choice (1-3mg/kg PO BID)*caution in dogs w systolic dysfunction (or form 3 ARVC)
Mexilitine: class 1 antiarrhythmic
Possible agents involved in myocarditis?
Parvo Paramyxo BacT Bartonella Borrellia Leptospirosis Toxo Trypto
T or F:
We will see arrhythmias (VPCs) in animals with myocarditis.
TRUE
How do we diagnose myocarditis?
Cardiac troponin 1-biomarker (leaked from DAMAGED/NECROTIC Cardiomyocytes!)
Myocarditis in the dog caused by Trypanosoma cruzi is called ?
Chaga’s dz
Categorize the general disorder:
Pericardial effusion - mostly right sided pressure overload with sanguineus hem fluid
Pericardial disorder
If cardiac tamponade is present in a patient you suspect has pericardial disorder, what do we need to do immediately (EVEN IF IT LOOKS FINE)?
Emergency pericardiocentesis!
Common cause of pericardial disorder in the dog?
Neoplasia;
HSA in R ATRIUM/AURICLE (Tx: doxorubicin chemo therapy)
Chemodectoma (aortic body tumor) in chemoreceptors cells in asc aorta/carotid body
Mesothelioma
Common cause of pericardial disorderk in cats?
Cardiovascular: CHF
How would we diagnose pericardial disorder on radiographs?
Bloboid cardiac silhouette d/t chronic severe pericardial effusion
T or F:
In pericardial disorder, we may treat the R-CHF with furosemide, however diuretics are contraindicated in the presence of tamponade.
TRUE AF