Cardiology Flashcards
Skipped/very minimal questions on echocardiographic variables unless in consensus or acronym study
Diuretics reduce preload or afterload?
Preload
What does furosemide do to the fractional excretion of sodium?
Increases it
Maximum dosage of furesomide/day?
12 mg/kg/d
Lasix-induced AKI in a CHF patient indicates that IVF are needed to correct dehydration. T/F?
False most of the time- CHF patients generally have maldistribution of fluids in venous circulation, and so IVF may actually worsen these. Ideal recommendation is to alleviate diuretic and also address heart failure with other modalities.
Mechanism of action of dobutamine?
B1 agonist (both inotropic and lusitropic effects)
What is a junctional escape rhythm?
escape rhythm originating from the N region of the AV node
T waves can be positive or negative in healthy dogs. T/F?
True
What is affected in a wandering pacemaker ECG?
Variations of P-wave morphology. Not pathologic.
Three ECG characteristics of a-fib
- Supraventricular complexes
- irregularly irregular rhythm
- no p-waves. F-waves are seen
A-fib and concurrent bundle branch block can look like what other rhythm disturbance? What are ways to distinguish the two?
Can look like v-tach. Can distinguish using vagal maneuver (v-tach will not slow); evaluate for regular R-R intervals (v-tach should still have regular R-R)
A-fib can be associated with what other concurrent morbidities?
Hypothyroidism, anesthesia (esp with opiates), rapid pericardiocentesis, GI dz, volume overload (causing atrial stretch), giant-breed dog, structural cardiac disease (like DCM)
Recommended meds for a-fib?
Digoxin and diltiazem
What is the diagnosis and treatment of a Torsade de Points ECG?
Follows prolongation of Q-T interval and R on T. Rapid (>180 beats/min) ventricular rhythm has QRS complexes that are more regular than in VF but that are continuously changing in amplitude
and polarity. Treatment is discontinuing anti-arrhythmics and starting IV infusion of mag sulfate.
Causes of high grade 2nd degree Mobitz type 2 and 3rd degree AV block?
Functional (hyperkalemia, digitalis intoxication, a2 agonist); structural - inflammatory vs degenerative
How are 3rd degree AV blocks in cats different vs dogs?
most cats (61%) have underlying structural heart disease which will not be reversed with pacemaker, and survival without pacemaker can be long even without presenting signs. (HR in cats is generally similar to what it is at home - around 80-140)
Cats are more likely to develop what type of bundle branch block?
Left anterior fascicle block (produces tall R wave in lead 1 but deep S wave in lead 2)
LBBB almost always is associated
with left ventricular enlargement. T/F?
True
Why are arrhythmias secondary to hypokalemia not responsive to class I antiarrhythmics (lidocaine, mexiletine, quinidine)?
Because they affect Na concentrations and depend on a normal K
What does hypocalcemia do to the threshold of action potential?
Decreases it.
What does hyperkalemia do to the resting potential?
Increases it (as in less negative)
What is the second most common site of ATE in cats with underlying
cardiac disease?
Right subclavian artery (right forelimb sign)
Top site is aortic bifurcation
What biochemical abnormalities are consistent with reperfusion injury?
Rapid development of life-threatening hyperkalemia and severe metabolic
acidosis
What are echocardiographic measurements that spark prophylactic anti-thrombotics in cats?
echocardiographic measurements of an end-systolic left atrial diameter
>1.7 cm or left atrium-to-aortic ratio (LA/Ao) >2.0
Two dog breeds in which DCM can be diagnosed before 1 year of age:
Portuguese Water Dog and Toy
Manchester Terrier
What is the first gene mutation in Doberman Pinschers that has been associated with DCM? Is this gene assocatiated with complete penetrance?
pyruvate dehydrogenase kinase 4 (PDK4) - incomplete penetrance, meaning not all dogs with the mutation will develop
disease and the expression of disease is variable
What is the cut-off for arrhythmias on a Holter that indicates a Doberman is at risk for development of DCM?
greater than 50 ventricular premature complexes (VPCs) per 24 hours, or with
couplets or triplets are suspect for the development of DCM
The use of pimobendan can help extend the time to CHF in Dobermans with occult DCM. T/F?
True (PROTECT study)
ARVC affected Boxers frequently have what ECG abnormality?
Left bundle branch block
Antiarrhythmic medications generally used for ARVC Boxers?
Sotalol and/or mexiletine
Most common auscultatory finding in R to L shunting PDA?
accentuated and split second heart sound
R to L shunting PDA dogs generally suffer complications secondary to what condition?
Hyperviscosity / sudden death. (CHF is uncommon)
ASD generally leads to right heart failure or left heart failure?
Right heart (or pulmonary hypertension)
For a VSD, a higher velocity of blood through the defect is more associated with a smaller or larger defect?
Smaller defect
Bull Terriers are associated with what kind of congenital heart disease?
Mitral and VALVULAR aortic stenosis [only breed known to have valvular form]
A splinted QRS complex is distinctive for what congenital abnormality in dogs and cats?
Tricuspid valve dysplasia
English Bulldogs and Boxers have what type of pulmonic stenosis and what other clinically relevant associated anomaly?
Subvalvular; anomalous development of coronary arteries
Newfoundlands are well-studied for what congenital cardiovascular anomaly?
SAS
Atenolol in severe SAS dog extended survival time compared to dogs without atenolol. T/F?
False - no difference. (Ettinger quoted JVIM 2014 study)
Features of tetralogy of Fallot
Pulmonic stenosis, VSD, right-ward positioned aorta, secondary RV hypertrophy
Two dog breeds more commonly known for Tetralogy?
Keeshond, English Bulldog
Rapid elevation of left atrial pressures with no corresponding left atrial enlargement and severe mitral regurgitation is consistent with
Mitral valve chordae tendinae rupture
How to calculate right ventricle pressure from right atrial pressure?
Adding an estimate of the RA pressure to the calculated pressure gradient
over the AV valve. Estimate of RA pressure is 5 mm Hg in the absence of RA dilatation, 10 mm Hg in the
presence of RA dilatation but no sign of right-sided CHF, and 15 mm Hg in dogs with right-sided CHF
Most frequent presenting complaint in dogs with infective endocarditis?
Lameness
Absence of fever is more common with endocarditis of which valve?
Aortic (and may be attributable to Bartonella?)
In positive blood cultures, what % should be positive after 72h?
90%
Microorganisms known to cause IE in dogs?
Staph, strep, Pseudomonas, bartonella, E coli, Corynebacterium, Erysipelothrix
Major criteria for diagnosis of infective endocarditis in dogs?
Vegetative/erosive lesion on valve; new valvular insufficiency (without SAS); positive blood culture (2 or more positives or 3 if common contaminant)
Recommended treatment for bacterial endocarditis?
Antibiotic (bactericidal - gram + and - spectrum) - parenteral (ideally IV) for first 1-2 weeks, and then SQ and then oral. Total treatment for at least 6 weeks. If Bartonella - monitor serology 1 mo after initiating tx.
First mutation noted in Maine Coons associated with HCM?
MyBPC3 Myosin Binding Protein C sarcomeric gene (Ragdolls can also have a mutation here)
Most common cause of ventricular arrhythmia in cat?
Myocardial disease (specifically HCM)
Two breeds that have shorter survival with HCM than other cats with HCM?
Ragdolls and Maine Coons
Unlike HCM, most cats with RCM are clinical for CHF at time of diagnosis. t/f/
true (same with DCM)
Why are cats prone to taurine deficiency?
low tissue concentrations of
cysteine-sulfinic acid decarboxylase (required enzyme for synthesis); also taurine is only amino acid used for bile acid conjungation
Taurine supplementation is generally recommended for feline DCM regardless of concentration. T/F?
True
Feline myocardial disease associated with shortest survival time?
Feline DCM
A subclinical cat with obstructive HCM can benefit from which beta-blocker?
Atenolol (beta-1 specific) [not as frequently prescribed for non-obstructive HCM as studies have not shown it to have a beneficial effect - now some clinicians do RAAS inhibitors or diltiazem]
What is pulsus paradoxus?
Abnormally decreased BP during inspiration. Fall of systolic arterial blood pressure >10 mm Hg during the inspiratory phase of normal breathing. With pericardial effusion, greater right ventricular filling during inspiration increases the pressure within the pericardial sac and pushes the interventricular septum leftward, both of which reduce the left ventricular chamber size, reducing left ventricular filling.
Most common cause of pericardial effusion in dogs?
Cancer (generally HSA - and if HSA, generally right atrium)
Which side heart failure is typically present in chronic pericardial effusion (if heart failure is present)?
Right sided heart failure
What % of idiopathic pericarditis cases have recurrent effusion?
50%
Most common cause of pericardial effusion in cats?
CHF
Which of the macrocyclic lactones does not have spectrum against rounds and hookworms in dogs?
Selamectin (apparently in Canada selamectin is labeled for use in hooks)
Which macrocyclic lactones can be used for slow-kill?
imidocloprid-moxidectin; selamectin; ivermectin (NOT milbemycin oxime or sustained release injectable moxi by itself)
When are corticosteroids indicated for canine heartworm?
pulmonary parenchymal complications (eosinophilic pneumonitis, eosinophilic granulomas, and PTE), to treat or prevent adverse reactions to microfilaricides, and
possibly to minimize tissue reaction to melarsomine.
Difference between eosinophilic pneumonitis and eosinophilic granulomatosis secondary to heartworm infection?
Both very responsive to steroids, but granulomatosis more likely to be more recurrent and may require second-agent. Granulomatosis has more nodular signs on CXR.
Development of clinical signs from heartworm-associated respiratory disease in cats can be avoided if the heartworms are not allowed to mature. T/F?
False
Primary lymphedema generally affects fore or hindlimbs? When does it generally present?
Hindlimbs; generally young. Generally bilateral but one side may be more affected.
Compression is generally effective for primary or secondary lymphedema?
Secondary
Which two breeds have higher cardiac troponins than other dogs?
Boxer and Greyhounds JVIM 2016 review
A significant increase in cardiac troponins have been identified in which cardiac myopathies?
HCM (JVIM 2016 review)
What is sensitivity/specificity of snap pro-BNP in determining cardiac vs noncardiac cause of pleural effusion in cats?
sens 95.2% and spec 87.5% - JVIM 2016
Plasma NT-proBNP in healthy Huntaways and herding dogs after work can exceed the upper limit of the reference range. T/F?
True - JVIM 2018
A relative increase in NT-proBNP in a cat on oral steroids is not likely secondary to steroid administration. T/F?
False. Steroids can cause increase NT-proBNP and heart size (specifically left ventricular internal diameter) - JVIM 2020
High proBNP (>100 pmol/L) detected all cats with HCM regardless of left atrial enlargement. T/F?
False. Detected all cats with LA enlargement but not without LA enlargement (Se was around 69% and specificity was 100%).
What was Se/Sp of proBNP ELISA for cats with murmur in detecting cardiac disease?
sensitivity of 71% and a specificity of 92% (i.e. positive means likely heart disease but neg doesn’t reliably exclude it) - JVIM 2021
What was Se/Sp of cTnI cutoff of 0.625 ng/mL for infective endocarditis?
100% specificity (95% CI 90%-100%) and 52% sensitivity (95% CI 33%-70%) - JVIM 2021
What was MST of medium/large sized dog that presents in heart failure from MMVD with afib?
142d (significantly shorter than those without which was around 234 d). Controlling rate also had longer time than those whose rate was not controlled. JVIM 2016
What was the most significant echocardiographic indicator of cardiac-related death in 1 year with MMVD?
Tei Index (JVIM 2016) (this is myocardial performance index - parameter for left ventricular function)
Leptin was higher/lower in dogs with CVD compared to healthy dogs.
Higher (JVIM 2016)
What % of dogs had an increase in peak tricuspid regurgitation following sedation?
78% JVIM 2017
Which of the following decreased when dogs with cardiomegaly due to MMVD were given sacubitril/valsartan (Entresto)? potassium, arterial pressure, urinary aldosterone to creatinine ratio, NT-proBNP
urinary aldosterone to creatinine ratio JVIM 2018
VLAS over what number was a useful predictor of LA enlargement?
2.3 (JAVMA 2018); but highest specificity (96%) was found with VLAS equal or greater than 3 [sensitivity 40%] - JAVMA 2020
Stage B2 criteria for MMVD?
Murmur intensity ≥3/6
La:Ao ≥1.6
Left ventricular internal diameter in diastole, normalized for body weight (LVIDDN) ≥1.7
Breed-adjusted radiographic VHS >10.5 (or in absence of echo “general breed” VHS ≥11.5) or evidence of accelerating interval change
Newer index of radiographic left atrial enlargement, VLAS ≥3 likely identified Stage B2
(Consensus/EPIC)