CVT Cardiology Flashcards
(313 cards)
1
Q
Which deficiency can be seen in cats with DCM?
A
Taurine deficiency (not as common now)
2
Q
Which breeds in dogs have been noted to have taurine deficiency related DCM?
A
American cocker spaniel, Newfoundland, Goldens
3
Q
Which supplement showed an increased survival in humans with DCM?
A
L-carnitine (role in long chain FA metabolism and energy production - Lots in heart)
No controlled studies in dogs
4
Q
What supplement should be offered to all dogs with DCM (esp Boxers)?
A
L-carnitine (role in long chain FA metabolism and energy production - Lots in heart)
No controlled studies in dogs
5
Q
Has an imbalance btwn oxidant and antioxidants been noted in dogs with DCM and CVD?
A
Yes! JVIM 2005
6
Q
What is an antioxidant and has a role in energy production that could be consider for supplementation in dogs with cardiac disease?
A
Coenzyme Q10
7
Q
What is an important component of diet in animals with cardiac disease?
A
Na restriction (based on level of their disease) - Should be <50 mg/100kcal
8
Q
What is neurocardiogenic (Vasodepressor) Syncope?
A
“reflex-mediated syncope o Incompletely understood adrenergic-stimulated baroreceptor reflex mechanism = inappropriate stimulation of baroreceptor reflex
o Sympathetic surge = “empty ventricle syndrome” = vagal stimulation to brainstem from ventricular mechanoreceptors = sympathetic withdrawal = vasodilation and bradycardia
o Usually follows fight, flight, fright, startle
9
Q
What is considered the #1 cause of syncope across all ages and breeds?
A
AV Block
10
Q
What is considered the #1 cause of syncope in older Schnauzers, WHWT, Cockers?
A
SSS
11
Q
What is considered a common cause of syncope in MR dogs?
A
Neurocardiogenic (Warning sign of high preload, rarely fatal)
12
Q
What are the 2 main diseases that can predispose to situational relfex-mediated syncope?
A
Advanced MVDD and pulmonary hypertension
13
Q
What is the #1 cause of syncope in cats?
A
AV block (neurocardiogenic and SSS rare)
14
Q
What is essential in the diagnosis of syncope?
A
Documenting the heart rate with Holter during event
15
Q
Name 4 metabolic causes of syncope.
A
- Hypoglycemia
- Endocrine (Addison’s)
- Hypoxia
- Anemia
16
Q
What is the definition of systemic hypertension?
A
Systolic BP > 160 mmHg
17
Q
What is the sensitivity and specificity of blood pressure readings when BP > 160 mmHg?
A
o Oscillometric and Doppler methods have only 53-71% sensitivity and 85-88% sensitivity in detecting BP > 160mmHg
18
Q
Name the top 3 diseases in cats that result in hypertension.
A
§ #1 CKD: 20-65% (probably more like 20-30%)
§ Hyperthyroid: 10-86% (probably more like 10-30%)
§ Diabetes: prevalence of SHT poorly documented
19
Q
What is important to remember about Sight hounds and blood pressure?
A
Sighthounds have BP 15 mmHg higher than other dogs
20
Q
Name the target organs that are damaged with hypertension.
A
- Kidneys: Esp > 160 mmHg risk of glomerular and tubulointerstitial changes
- Ocular: Esp > 180 mmHg retinal/intraocular hemorrhage, vascular toruosity, retinal detachement
- Brain: Esp > 180 mmHg seizures, mentation change, vestibular dz
21
Q
How long did it take for systemic hypertension to result in cardaic hypertrophy in dogs?
A
About 12 wks
22
Q
What happens with the blood pressure cuff is too small?
A
cannot occlude artery so measured pressure HIGHER than actual pressure
23
Q
What happens with the blood pressure cuff is too large?
A
occludes artery too soon so measured pressure LOWER than actual pressure
24
Q
What is the ideal cuff size?
A
40% circumference of limb
25
Why do most animals (and humans) need multiple medications to control BP?
o May occur b/c need to directly vasodilate (amlodipine) AND limit ability of compensatory mechanisms to adjust to medication-induced changes (ACE-I)
26
What is the major concern of using Ca2+ channel blockers alone?
preferential dilation of renal afferent arterioles = increased intraglomerular pressure and can cause glomerular damage; ACE-I can protect glomerulus
27
What is the step wise apporach for chosing hypertension control in dogs?
□ ACE-I: decrease in BP 10%, limit proteinuria; can start SID and go up to BID if needed
□ Amlodipine: start SID, go to BID if needed; long half-life in dogs = evaluate after 1 week
□ Refractory HT: search again for underlying causes; consider hydralazine, prazosin, spironolactone, diuretics (proceed carefully and add each one step-wise with close BP monitoring; no good data on multi-drug plans in animals
28
Name 3 indications for pacing in dogs.
SSS, AB block, atrial standstill
29
What are the most common type of pacing?
transvenous, single-lead, single-chamber ventricular pacing (VVI)
30
What does VVI stand for in pacing?
ventricle is paced, ventricle is sensed, and the pacemaker inhibits itself in response to detection of native electrical activity
31
What are 4 parameters that can be adjusted in a pacemarker?
o Pulse Width: Duration of the pacemaker discharge in miliseconds
o Amplitude: Intensity of the pacemaker discharge in volts
o Sensitivity: Ability of the system to detect native electrical activity in the atria or ventricle
Refractory Period: Duration of time following a sensed or paced event that all activity is ignored by the pacemaker
32
What is a potential risk if your sensing and timing of discharge are off?
Ventricular fibrillation
33
What percentage of dogs had complications during pacemarker implanation?
About 55%
34
What is the most common complication with pacemarker implantation?
10% Overall dislodgement rate = Loss of sensing or pacing
35
What percentage of dogs got an infection of their pacemarker?
About 5 %
36
What percetnage of dogs are still alive at 3 years after placement of a pacemarker?
About 50%
37
What is rate responsive ventricular pacing?
§ Uses an activity sensor that attempts to match the paced heart rate with the patient’s activity (accelerometer, minute-ventilation sensor, thermometer, gravitation sensor or QT-interval sensor)
38
What is dual lead, dual chamber pacing?
(most commonly used in people) § Uses a second pacing lead within the right auricular appendage. This senses and paces the atrium, then stimulating a timed ventricular depolarization afterward via the right ventricle.
§ Retains AV synchrony.
39
What is pacemarker syndrome?
When atrial contribution to cardiac output and contraction of atria against closed AV valve - Leading to weakness, dyspnea, heart failure
40
What type of pacing is more physiologic and why?
Dual chamber pacing - It preserves syncrhony btwn atria and ventricles
41
What is SVT?
Rapid rhythms originating in the atria or using the atria or AV junction above the bundle of His as a component of the tachycardia circuit.
42
What is the purpose of a vagal maneuvers?
increase vagal toneàslowed sinus node discharge, prolonged AV conduction and refractoriness.
§ If an SVT abruptly terminates in response, possibilities are AV nodal re-entrant tachycardia, orthodromic AV reciprocating tachycardia, or sinus nodal re-entrant tachycardia. Lack of response doesn’t rule these out.
43
If blood pressure is compromised by SVT and patient does not repond to vagal maneuver, what can be tried?
Diltiazem (Slows AV node conduction and prolongs AV refractory period)
Esmolol (Short acting selective B1 blocker)
Procainamide (prolonges refractory period of ventricules)
44
Name 4 drugs that can work on the SA node.
1. Beta Blockers
2. Calcium channel blockers
3. Digitalis
4. Class III (K+ channel blocker)
45
Name6 drugs that can work on the AV node.
1. Digoxin
2. Beta Blockers
3. Calcium Channel Blocker
4. Class III (K+ channel blocker)
5. Class IC (Na+ channel blocker)
6. Adenosine
46
What can occur with persistent tachyarrhythmia?
Structural and electrical remodeling
47
What are 3 indications that you should treat ventricle arrhythmias?
1. Clinical signs (hypotension = weakness, lethargy, exercise intolerance, syncope)
2. tachycardiomyopathy
3. Harbor the risk of death
48
In general which is worse, polymorphic VPCs or monmorphic?
Polymorphoric (except in Boxer with ARVC)
49
What is the frequency that R on T can result in V fib/sudden death in dogs?
Unknown!
50
What if German Shepherd VT?
young dogs (death 15-52 weeks); sudden death in 15% of affected dogs; rapid polymorphic VT; usually survive if make it to 2 years; mechanism thought to be triggered activity from early and delayed after depolarizations (don’t know how sustained VT or Vfib occur); death associated with changes in autonomic tone (sleep, early morning excitement)
51
What are 2 electrolyte abnormalities that should be considered if Vt not responding to lidocaine?
Hypokalemia and hypomagnesemia
52
If lidocaine fails for Vtach what other options are there?
Procainamide
Amiodaraone
PO sotalol, meiletine
53
What is the most common cause of arrhythmia in cats?
Associated with primary cardiac disease (generally do NOT present for CS related to arrhythmia (incidental)
54
What are the most common arrhythmias in cats?
BBB or LAFB (48.2%)
VPC (34%)
SVT (24%)
Av Block (12%)
55
What are the most common causes of 1st degree AV block in cats?
Digoxin toxicity, high vagal tone, structural heart diseases, no clinical significance
56
What are the most common causes of 2nd degree AV block in cats?
Cardiomyopathy, conduction, or alpha 2 agonists
| Need pacemarked it clinical
57
What are the most common causes of 3rd degree AV block in cats?
```
Older cat (> 11 yrs) 0 Cardiomyopathy, infiltraive dz, other structural heart dz, hyper T4, idiopathic (conduction system degeneration)
Need to treat with pacemaker if escape rate
```
58
What should you try first for VT in cats?
Beta blocker (IV - Propranolon or esmolol; PO - atenolol)
59
What does ST segment elevation suggest?
Myocardial hypoxia
60
What is cardioversion?
external transthoracic delivery of a DC current shock for restoration of sinus rhythm in patients with ventricular or SV tachyarrhythmias
61
When is a shock delivered to avoid inducing V fib?
Shock synchronized to R wave of QRS complex
62
What is cardioversion the most effective at treating?
Impulse re-entry (Afib, Aflutter, AV node re-entry, AV reciprocating tachycardias w/ accessory conduction, and Vtach)
63
How does cardioversion work?
shock simultaneously depolarizes all excitable myocardium and prolongs refractoriness = interrupts re-entrant circuits and establishes electrical homogeneity, terminating re-entry
64
When should cardioversion be considered?
Any tachycardia producing hypotension or CHF which does not respond to medical management
65
What is PDA and what does it stand for?
Patent ductus arteriosus
| persistence of fetal ductus arteriosis = communication between descending aorta and MPA
66
What is the most common signalment of PDA?
Female (3:1) - Not in all breeds
67
What is the most common arrhythmia associated with PDA?
A-fib
68
What is the treatment for PDA?
Ductus closure ASAP! Surgical ligation or vascular occulsion
69
What is the standard vascular occluder for PDAs?
Amplatz canine ductal occluder
70
Which is better for PDA treatment, sx or catheter-based occlusion?
No difference in mortality
| More major complicatons with sx and more minor complications with catheter based
71
What is a ventricular septal defect?
Hole in IVS allowing communication btwn RV/LV (present at birth)
72
Which spp are VSD more common in?
Cats
73
Which breeds get VSD?
WHWT, Lakeland terriers, English bulldogs, English springer spaniels (inherited)
74
What does a VSD result in?
Left to right shunt = Left sided volume overload
75
If a VSD results in excessive pulmonary overcirculation what can occur?
Development of pulmonary hypertension = Eisenmenger's physiology
RV pressure overload = Promotes bidirectional or Right to left shunting (opposite from original direction)
76
Name 4 conditions that can results in right to left shunting.
§ Eisenmenger’s physiology (pulmonary hypertension reversing a left to right shunt)
§ Tetralogy of Fallot: VSD complicated by RVOTO and RV hypetrophy; right-to-left shunting predominates = hypoexemia, polycythemia
§ Double-chamber right ventricle: fibromuscular reaction and proliferation in RV = midventricular obstruction just distal to VSD (may close the VSD) = high pressures in proximal chamber = concentric hypertrophy of proximal chamber
§ Concurrent VSD and severe PS
77
How would Eisenmenger's physiology appear on CXR?
o Eisenmenger’s physiology: MPA enlarged but remainder of pulmonary arteries small
78
What is the typical murmur for VSD?
"Blowing" Systolic murmur at right sternal border
79
What are CS that can results with right to left shunting?
Exercise intolerance, hypoxemia, polycythemia
80
What are 2 options to treat polycythemia?
Phlebotomy (to 62-65%)
| Hydroxyura (bone marrow suppression)
81
Name 3 breeds that get pulmonic stenosis.
terriers, English bulldogs, Samoyeds, Chihuahuas, miniature Schnauzers, Labs, mastiffs, Chows, Newfoundlands, Basset hounds, Cockers; inherited in Beagles
82
What are the 3 types of pulmonic stenosis?
Subvalvular, valvular, supravalvular
83
What is a potential risk in certain breeds with pulmonic stenosis? Which breeds are affects?
· Anomalous left coronary artery (Bulldogs, Boxers):
o Single large coronary artery originates from right aortic sinus = divides into left/right
o Left coronary artery encircles MPA below valve = subvalvar obstruction
84
What is the most common murmur with pulmonic stenosis?
o Systolic murmur with PMI at left heart base; harsh ejection-quality crescendo-decrescendo
85
With moderate to severe pulmonic stenosis what would you see on CXR?
o Moderate to severe: RV enlargement, post-stenotic MPA dilation (DV > lateral)
86
Based on color doppler, velocity across pulmonary stenosis what are the grades?
§ PG = 4v2
§ Mild: up to 40-50mmHg
§ Moderate: 40-80 (or 100)mmHg
§ Severe: >80 (or 100) mmHg
87
What is potential medical treatment for pulmonic stenosis?
Treat CHF if present
| Atenolol
88
What is the preferred treatment for pulmonic stenosis?
Balloon valvuloplasty
89
When should balloon valvuloplasty be considered for pulmonic stenosis?
o Should be performed ASAP = waiting only causes more RV hypertrophy
o Complication: “suicide right ventricle” = dynamic infundibular stenosis can become more severe following ballooning = increase in RV pressure as hypertrophied infundibulum creates subvalvar obstruction that can be worse than valvular obstruction)
o Bulldogs/Boxers with anomalous left coronary artery: ballooning can cause rupture of MPA and sudden death; can try less aggressive dilation, or surgical conduit around stenosis
90
What are potential major complications with balloon valvuloplasty?
o Major complications (rare): cardiac perforation, rupture of MPA, suicide RV, fatal arrhythmias
91
What are potential minor complications with balloon valvuloplasty?
Minor complications (more common): damaged TV, RBBB, temporary arrhythmias, hemorrhage from vascular access sites
92
Why can pressure gradients be higher following balloon valvuloplasty?
o PG may be higher after procedure vs. during (pulmonary valve leaflets can swell and cause increased obstruction; also, awake dogs have higher SV than anesthetized)
93
What is the long term prognosis for pulmonic stenosis if balloon valvuloplasty is performed?
Excellent (normal lifespans)
94
What is subaortic stenosis?
Fibrous lesion that partially or completely encircles subvalvular outflow tract
95
Which breeds get subaortic stenosis?
Newfoundlands (heritable; polygenic or autosomal dominant); GSD, Boxer, Golden, Rottweiler
96
What is important to consider about the pathogenesis of subaortic stenosis?
o Not present at birth; develops early in life (begins within 3 weeks) d/t morphologic abnormalities in LVOT that increase shear stress and induce proliferation of cells in LVOT; may progress for first 12mo
97
What are common complications with subarotic stenosis?
§ Severe: sudden death, arrhythmias (within 2-3 years)
| § Mild-moderate: infective endocarditis, CHF
98
What is the classic murmur for subarotic stenosis?
Left basilar systolic murmur
99
What can you feel in the pulses of animal with subaortic stenosis?
o Arterial pulses tardum and parvum (weak and late-rising)
100
Besides LV hypertrophy what can be seen on ECG for patient with subarotic stenosis?
ST segment depression suggests myocardial ischemia = Based on increased pressure gradient resulting in narrowed coronary vessles = myocardial ischemia
101
What can be seen on CXR in animals with subaortic stenosis?
post-stenotic dilation of ascending aorta
102
What is the primary diagnostic criterion for SAS on echo?
Peak Ao velocity is primary diagnostic criterion for SAS
| § Most think that >2.25m/s is definitely mild SAS; between 1.9-2.25m/s is grey zone
103
Which breed has a relative aortic stenosis and what is this?
Healthy Boxers: >50% have soft basilar ejection murmurs; those with murmurs have higher aortic velocities than dogs without murmurs = may be breed-related variance in outflow tract anatomic
104
What are the treatment options for SAS based on degree?
o Mild/moderate: not treated; generally have few complications and live normal lifespans
o Severe: often die suddenly from ventricular arrhythmias, but no good treatment option
105
Is there a benefit of balloon valvuloplasty in dogs with SAS?
NO! Not compared to atenolol alone
§ Presumed benefit of atenolol: decrease myocardial O2 demand (negative inotrope and chronotrope); improve myocardial perfusion during diastole; blunts SNS-instigated reflex-mediated syncope; may reduce arrhythmias?
106
What are the gradients for SAS grades?
§ Mild: 80mmHg
§ Pressure gradient is flow-dependent = depends on CSA and stroke volume (SNS activation will worsen apparent stenosis)
107
What is tricupsid valve dysplasia?
congenital malformation of right AV valve apparatus caused by abnormal tissue undermining of the RV during embryogenesis o Variety of abnormalities
§ Thickened, shortened, or elongated leaflets
§ Shortened or absent chordae tendinate
§ Abnormal papillary muscles
108
What is Ebstein's anomaly?
Seen in animals that get tricspid dysplasia! congenital defect where origins of tricuspid leaflets are apically displaced into RV; may be associated with leaflet dysplasia; rare in vetmed
109
Which breeds get tricuspid valve dysplasia?
Labs (inheirted), Boxers, Goldens, Irish setters, Great Danes, GSD
110
What ECG abnormality is seen on 2/3 dogs with tricuspid valve dysplasia?
```
o Splintered QRS in 2/3 of dogs (mechanism unknown; may be ventricular fibrosis, RBB conduction disturbances, accessory pathway conduction)
Atrial arrhythmias (APCs, AT, A flutter, Afib)
```
111
What is seen on CXR with tricuspid valve dysplasia?
o Right heart enlargement
| o HUGE RA but normal MPA
112
What is treatment for tricupsid valve dysplasia?
o Instituted once R-CHF develops
o Furosemide, ACE-I, abdominocentesis, low Na+ diet, +/- pimobendan?
o Atrial fibrillation: digoxin, diltiazem
Balloon Valvuloplasty - reported twice was horrible!
113
What is the prognosis for dogs with tricuspid valve dysplasia?
depends on severity o Mild: may have normal lifespans
| o Severe: R-CHF within a few years, though may survive >6yrs with treatment
114
What may be considered the #1 congenital cardiac abnormality in cats?
Mitral valve dysplasia
115
Which dogs breed get mitral valve dysplasia?
Great Danes, GSD, bull terriers, Goldens, Newfoundlands, Dalmatians, mastiffs
116
How is heart failure different from shock?
inability of the heart to maintain CO sufficient to meet tissue perfusion needs given adequate venous pressures (as distinguished from shock that has impaired venous return)
117
What happens during heart failure?
o Decreased CO and BP à trigger compensatory systems to maintain basal BP and target organ blood flow
§ SNS stimulation of heart
§ Vasoconstriction and redistribution of blood flow (SNS, RAAS, vasopressin, vascular endothelial systems)
§ Na+/water retention (RAAS, vasopressin, inhibition of natriuretic hormones)
o Chronic stimulation of control mechanisms à chronic states of vasoconstriction, Na+ retention, mediators of inflammation and tissue growth; heart remodeling (activation of fetal-gene programs, myocyte apoptosis, interstitial and replacement fibrosis)
118
What are the most common causes of heart failure in dogs?
MVD, DCM, pericardial disease, or HWD/PHT
119
What is the most common acquired heart disease in dogs?
Chronic valvular dz, Overall incidence > 40%
120
In which breed is chronic valvular disease considered to be genetic?
CKCS
121
Chronic valvular disease has generally been considered a non-inflammatory myxomatous vlave degeneration but newer evidence suggests what?
Role of serotonin, C-reactive protein, inflammatory cytokines, serotonin-transforming growth factor
122
What is the pathophysiology of chronic valvular disease?
valvular thickening → valvular regurgitation → dilation and hypertrophy of atria/ventricles → compensatory mechanisms (SNS, RAAS) to prevent CHF o CHF occurs when volume overload overwhelming, chordal rupture, or LV myocardial failure
o L-CHF can lead to PHT → R-CHF
123
Which sex is more effected by chronic valvular disease?
Males> females
124
What is known about treatment of asymptomatic dogs with chronic valvular disease with ACE-I?
Controversial (SVEP vs VETPROOF trials) - Generally only for moderate to severe cardiomegaly
125
What are the 3 mainstays for at home management of CHF?
Furosemide
ACE-I
Pimobendan
126
When do you consider that a CHF patient may have diuretic resistance?
When furosemide >2.2 mg/kg q12hrs
127
What should be used if a ruptured chordae tendinae has occurred?
Nitroprusside (titer systolic BP to 90 mmHg)
128
Name 3 main reasons for pulmonary hypertension?
Primary, secondary (chronic resp dz or long standing L-CHF)
129
What is infective endocarditis?
Microbial invasion into endothelium of heart valve = proliferative or erosive lesion
130
Which bacteria results in fibroblast proliferation during infective endocarditis?
Bartonella
131
What percentage of dogs with infective endocarditis have Bartonella?
About 28% and about 45% of dogs that have negative blood cultures
132
Which valve is more affected with bacterial endocarditis?
Aortic valve
133
What is the difference btwn endocaritis and endocardiosis?
Osis = Maintain normal glistening surface
| It is = disrupts surface (rough, broken) - NOT glistening
134
Name several predisposing factors for infective endocarditis?
Bacteremia = Disko, prostatits, pneumonia, UTI, pyoderma, dental dz, catheters
Structural heart dz = SAS
Immunosupression
Steroids?? (controversial)
135
What is the classic signalment for infective endocarditis?
Medium to large breed, male
136
Which breed is predisposed to infective endocarditis?
GSD
137
Which heart valves are more affected with infective endocarditis?
Mitral and aortic (left sided valves)
138
Which is the #1 presenting CS in dogs with infective endocarditis?
Lameness
139
If a patient has a diastolic murmur or new murmur what should you consider?
Infective endocarditis (89-96%)
140
How many cases with infective endocarditis will have a negative blood culture?
60-70% of cases
141
What are the most common isolates for infective endocarditis?
Staph, Strep, E. coli
142
What is the sensitivity and specificity of blood cultures for infective endocarditis?
Sensitivity: 20%
Specificity: 93%
143
What is the sensitivity and specificity of panbacterial PCR (16 rRNA) for infective endocarditis?
Sensitvity: 33%
Specificity: 94%
144
What criteria are used for a diagnosis of infective endocarditis?
Modified Duke Criteria = need 2 major or 1 major + 3 minor or 5 minor
Possible: 1 major + 1 minor, or 3 minor
Reject: resolution within 4 days
145
What are the major criteria for infective endocarditis?
ECHO - vegatative lesion, erosive lesion, abscess
New valvular insufficiency (esp if AI with no SAS)
2 + blood cultures
146
What are the minor criteria for infective endocarditis?
```
Fever
New murmur (esp diastolic)
ECHO - Valve thickening, AI
Medium to large dog (>15 kg)
SAS
Sequela = Thromboembolic dz, polyarthritis, glomerulonephritis
1 + blood culture
Bartonella serology (> 1:1024)
```
147
What are potenial sequlea of infective endocarditis?
1. CHF
2. Immune-complex dz (IgM, IgG, C3) - Polyarthritis (75%), glomerulonephritis (36%)
3. Thromboembolism - 70% at necrospy (kidneys, spleen, myocardium, brain)
148
What is the treatment for infective endocarditis?
Long term (12 wk) bacteriocidal antibiotics
149
When should prophylaxic antibiotics be given to dogs?
In dogs with SAS to prevent infective endocarditis prior to a procedure
150
What is the prognosis for infective endocarditis?
Grave = weeks to months
151
What disease is defines as myocardial disease that has systolic and diastolic dysfunction with chamber dilation?
Dilated cardiomyopathy
152
What are potential sequela of DCM?
CHF
| Sudden death
153
What are 4 sporadic causes of DCM?
1. Viral myocarditis
2. Tachycardia-induced
3. Taurine deficency
4. Carnitine Deficiency
154
What is the classic signalment for DCM?
Large and giant breed dogs; males
155
What breeds predilection for DCM occurs in the US?
Dobermans, Irish Wolfhound, Great Dane, Boxer, American Cocker
156
Which dog breed does not fit the classic signalment for DCM?
Cocker spaniel = consider taurine def
157
Which dog breed has a juvenile form of DCM?
Portuguese water dog
158
In Dobermans with is the association of VPCs and the development of DCM?
>100 VPC in 24 hrs = Will develop DCM
159
What presentage of dogs have atrial fibrillation at presentation for DCM?
About 75-97%
160
What is the prognosis for DCM?
Guarded to poor
161
What are 4 negative prognostic indicators for DCM?
1. Younger age
2. Breed
3. R-CHF
4. Afib
162
For what drug is there a benefit in asymptomatic dogs with DCM?
ACE-I for DCM
163
What is digoxin?
Weak + inotrope, neurohromal modulation (normalize baroreceptor activity - decreased SNS activation)
Treatment for DCM
164
If you have a DCM dog and they have Afib and are not responding to digoxin alone, what can you add?
Diltazem, then atenolol (3rd line)
165
What is arrhythmogenic right ventricular cardiomyopathy
Primary myocardial dz with 3 forms
1. Asymptomatic with VPCs
2. Symptomatic with VPCs
3. Ventricular dilation, systolic dysfunction, VPCs/SVPCs
166
Which breed gets ARVC?
Boxers
167
What is the classic ECG finding in boxer with ARVC?
VPC, LBBB morphology (right sided)
168
How is ARVC diagnosed?
Holter!! To establish pre-tx freq and complexity of arrhythmia
High suspicion if >100 VPC in 24 hrs and lots of complexity (couplets, triplets, bigeminy, Vtach)
169
Why can the holter examination be normal in boxer with ARVC?
Up to 83% day to day variation in VPC freq in boxer
170
What is the correlation bwtn # or complexity of VPCs in ARVC?
NO correlation bwtn # or complexity of VPCs and development of CS in affected dogs
171
When should you consider treatment for an asympatomatic boxer with ARVC?
When > 1000 VPCs in 24 hrs
Runs of V Tach
or R on T
172
What are treatment options for ARVC?
Sotalol
Mexiletine + sotalol/atenolol
Rapid Holter about 2-3 wks after tx started (need 80% reduction in VPCs and reduction in complexity)
173
Which breed gets a slowly progressive primary myocardial disease leading to ventricular tachyarrhythmias, sudden death, CHF?
Dobermans
174
What percentage of dobermans with DCM will die of sudden death?
About 30-50%, due to rapid Vtach that leads to V fib
| More common in AM or after exercise
175
What are the mainstays for DCM treatment?
ACEi, spironolactone, B-blockers
176
What are the mainstays for DCM treatment?
```
ACEi, spironolactone, B-blockers
For dobermans with DCM what are the recommended anti-arrhythmic treatments? "Mexiletine
then carvedilol (if no CHF) and then amiodarone"
```
177
When should you consider pimobendan in DCM?
For sure when dog is in CHF but maybe need to consider when FS
178
What does syncope predict in dobermans with DCM?
Unlikely to progress to end-stage CHF but rather die of sudden death
179
What is myocarditis?
insidious inflammatory disorder of myocardium characterized by leukocyte infiltration and nonischemic myocyte degeneration and necrosis
180
Name common infectious causes of myocarditis?
Viral: parvovirus, distemper, herpesvirus, coronavirus, others
Bacterial (various)
Rickettsial: Richettsia, Ehrlichia, Bartonella
Spirochetal: Borrelia, Leptospira
Fungal (various)
Algal: Prototheca
Protozoal: Trypanosoma, Toxoplasma, Neospora, Trichineslla
181
What are CS that may suggest myocardial abnormalities?
sudden onset ventricular arrhythmia, syncope, weakness, CHF, sudden death
182
What do high levels of cardia Troponin I suggest?
Acute myocarditis (with mycytoysis and necrosis)
183
What serologic testing should be performed when myocarditis is suspected?
Toxoplasmosis, borrelliosis, rickettsial dz, Barontella, Chagas dz
184
What is thought to predispose cats to acute endomyocarditis?
URIs
185
What should be consider in cats (paritcullary from Northern California) if transient fever, depression, lethargy, lymphadenopathy, myocarditis, and diaphragmitis?
Transmissible Myocarditis and Diaphragmitis (no caustive agent)
186
What are the 4 most common secondary causes of mycoarditis in dogs?
Distemper, toxoplasmosis, lepto, leishmaniasis
187
Which viral infection resulted in puppies with sudden death and CHF and potential DCM?
Parvovirus (no cases since 1980s)
188
What is the causative agent of Chagas's disease?
```
§ Trypanosoma cruzi (hemoflagellate protozoon parasite)
# 1 mycoadritis in humans and dogs in latin america
```
189
If you have a dog that has AV block and mycocarditis what should be considered?
Lyme (Borrelia burgdorferi)
190
What causative agent result in multifocal myocarditis and valvular endocarditis?
Bartonella (B. vinsonii ssp berkhoffi)
191
In which breed is atrial myocarditis described?
English springer spaniel - Unknown etiology
| Atrial standstill, complete AV block
192
Name the 7 most common secondary causes of myocarditis?
```
Parvovirus
Distempter Virus
Bartonella
Borrelia
Leptospira
Trypanosoma
Toxoplasma
```
193
What are 2 causes of secondary myocardial disease in cats?
Hyperthyroidism
| Hypertension
194
Which spp have a significant number of functional heart murmurs = no obvious anatomic or physiologic causes?
Cats!
195
What are the mainstays of HCM treatment?
1. B-blockers (reduce myocardial O2 consumption, slow HR)
2. ACEi
3. Ca channel bockers (slower HR, reduce dynamic OTO)
196
What should be consider in cats with HCM and DLVOTO?
Atenolol to control DLVOTO but not severe bradycardia
197
What can be considered in low-output CHF?
Dobutamine: + Inotrope improve CO regardless of underlying pathology (but will increased myocardial O2 consumption)
198
What are the main treatment goals for HCM?
prevent Na+/H2O retention (lasix), modulate neurohormonal activation ACEI), delay myocardial changes (spironolactone), prevent ATE
199
What is a poor prognostic indicator for ATE cats?
Hypothermia
200
What disease in cats results in progressive atrophy of RV myocardium with fibrous and/or fatty replacement?
Right ventricular cardiomyopathy in cats
201
What are the most common cat breeds to get right ventricular cardiomyopathy?
DSH and Birmans
202
What is the prognosis for right ventircular cardiomyopathy in cats?
Poor prognosis once in CHF - progressive!
| Some cats remain asymptomatic
203
What is the classic signalment for ATE?
Middle aged males, mixed breeds (Abyssinian, Birman, Ragdoll
204
IN what percentage of cats is ATE the first sign of heart disease?
76% of cases
205
What is the number 1 neoplasia that can result in ATE?
Pulmonary carcinoma - Embolization of tumor cells from lungs
206
What are considered to be the survival characteristics in cats with ATE?
```
1 Limb affected
Some moto function
Higher rectal temps
High HR
Lower serum Phosphorus
```
207
What was the best predictor of survival in cats with ATE?
Rectal temp (50% survival at 98.9 F)
208
What are the mainstays in treatment of ATE?
Unfractionated heprain, low dose aspirin, analgesia, supportive care, CHF tx if needed
209
Why is warfarin not recommended for ATE?
No benefit over aspirin in survival and higher risk of hemorrhage and lots of monitoring needed
210
What are considered risk fators for ATE on echo?
Large artial size
""Smoke"" in atria
Consider antiplatelet or anticoagulant (no consensus yet)
211
What is percardial effusion?
excessive fluid accumulation (normal: ~0.25mL/kg) fluid accumulation between outer fibrous parietal pericardium and inner serous visceral pericardium (epicardium)
212
What is the pathophysiology of cardiac tamponade?
Pericardium noncompliant, so increased fluid volume leaded to increased intrapericaridal pressure = Excessed cardiac filling pressure = tamponade = limits heart filling = increased venous pressures with decreased CO (can reduce coronary perfusion, can lead to shock)
Even small volume can be horrible if acutely!
213
What is pulsus paradoxus?
§ Cardiac tamponade exaggerates variation in arterial BP occurring during respiratory cycle
§ Inspiration normally causes decrease in left heart output (right heart pressing on left) = exaggerated in pericardial effusion causing up to 10mmHg fall in arterial pressure during inspiration
214
What are the most common causes of pericardial effusion in dogs?
Neoplastic or idiopathic
215
What are the most common causes of pericardial effusion in cats?
CHF or FIP (less likley LSA, systemic infections, renal failure)
216
What are the most common neoplastic causes of pericardial effusions?
HAS (#1) - Right auricular (GSD, Goldnes, large breeds)
Heart Base Tumor (chemodectoma) = #2 - Boxer, Bosten terriers, Bulldogs
Pericardial mesothelioma
217
What is the classic signalment for idiopathic pericardial effusion?
Medium to large breed dog (6-7yrs)
218
What are potential causes for transudate effusion(modified) pericardial effusion?
CHF, peritoneopericardial diaphragmatic hernia, hypoalbuminemia, pericardial cysts, toxemias (uremia), increased vascular permeability
219
What bacteria should be consider in patients with exudative pericardial effusion?
§ Infection from plant awn migration, bite wounds, other (aerobic and anaerobic bacteria, actinomyces, coccidiomycosis, TB, systemic protozoal
§ Sterile exudate: leptospirosis, distemper, uremia, idiopathic PE; cats with FIP and toxoplasmosis
220
What is the classic sign on ECG of pericardial effusion?
Electrial alternans
221
Discuss the use of pH of pericardial effusion to differentiate underlying disease?
High pH = noninflammatory (neoplastic) and low pH = Inflammatory (idiopathic/infectious)
No correlation in dogs :(
222
On which side is it ideal to perform a pericardiocentesis?
Right side (cardiac notch to reduce lung injury)
223
What MUST be monitored when performing a pericardiocenetsis?
ECG!
224
What is the prognosis for idiopathic pericardial effusion?
Good prognosis (drainage to pleural space with pericardiotomy or ectomy)
225
Why is feline heartworm disease under diagnosed?
cats frequently amicrofilaremic, serologic tests lack Sn/Sp for cats, worm burdens are small, aberrant sites more common than dogs, clinical signs nonspecific, and easily mistaken for asthma
226
What percentage of indoor cats have HW?
About 25%, even though they are 100% indoors
227
Why do feline HWI result in asthma like syndrome?
pulmonary response to in situ heartworms includes type II cell hyperplasia and activation of pulmonary intravascular MPs
228
What percentage of cats are microfilaremic with HWI?
About 20-35%
229
Why is the antigen SNAP test not good for feline HWI?
virtually 100% specific, but very insensitivy (cannot detect low worm burdens); detect antigens from reproductive tracts of mature female worms = not immagutre worm (
230
How can the HW antibody test be used in cats?
Good to rule OUT infection (>99% negative predictive value)
| Negative = no infection or early (
231
Why do we not really need to HW test cats before starting on prevenative?
Cats are rarely microfilaremic and prevenative not rapidlu microfilaricidal
232
What treatment is recommended in cats with HWI?
Montly preventative, short term steroids if resp signs
233
A pulmonary artery > 1.6 times diameter of 9th rib on rads is suggstive of what disease in cats?
Heartworm
234
What is a causative agent of heartworm disease?
Dirofilaria immitis
235
What is the intermediate host of HW?
Mosquito
236
What life stage is ingested by mosquito from infected animal with HW?
L1 (microfilaria)
237
What life stage is transmitted to host following mosquito bite with HWD?
L3 = Infective
238
When are HW considered to be in the lungs?
About 100 days post infection (L5)
239
What is the patency of infection for HW?
About 6 months
240
What are several reasons that you could have a false negative HW SNAP test?
immature infections, low worm burden, all-male infections, circulating Ag-Ab complexing
241
What are the classes of HWI in dogs?
§ Class 1: mild (no clinical signs or occasional cough, no CXR signs)
§ Class 2: moderate (occasional cough, exercise intolerance mild CXR signs)
§ Class 3: severe (cough, dyspnea, R-CHF, exercise intolerance; severe CXR signs)
§ Class 4: very severe (caval syndrome)
242
What is caval syndrome in HWI?
acute syndrome associated with large worm burden, severe PHT, RV dysfunction with tricuspid regurgitation; see hepatic congestion and IV hemolysis with hemoglobinuria
243
What is the treatment for caval syndrome with HWI?
HW extraction
244
What is the adulticide treatment for canine HWI?
Melarsomine, Split dose (1 injection then 1 month later 2 injections 24 hrs apart) § Split-dose has higher success than 2-dose (90% vs. 76% conversion to seronegativity), decreases lung injury, and allows for delay if significant adverse reaction; only drawback is cost, longer period of exercise restriction, and total increased dose of arsenical (may be bad if CKD)
245
Why is monthly preventative used in treating HWI?
prevent further infection, destroy developing L4s that are not susceptible to adulticide, and eliminate microfilaria
246
What organism when treated with tetracyclines caused HW female worm infertility?
Wolbachia (obligate intracellular gram-negative bacteria (Rickettsial))
247
What is reach back with HW preventatives?
Efficacy against older infections than just larval
248
Which preventative should be given as a microfilaricidal?
Milbemycin
249
If a hyperthyroid cat presents with DCM, what should they be evaluated for?
Taurine deficiency
250
What are the 2 most common causes of feline congential heart defects?
Mitral dysplasia and ventricular septal defects
251
Why are feline RBCs more susceptible to oxiadtive injury?
Greater quantity of sulfhydryl groups on Hbg and reduced ability to convert methemoglobin to oxyhemoglobin
252
What type of toxicity can occur with sodium nitroprusside?
Cyanide and thiocyante
253
What is the benefit of nitroprisside administration?
Systemic and pulmonary dilation = Controlled reduction in preload and afterload
254
When is nitroprusside useful?
Severe hypertension
| Catastrophic heart failure
255
Which mutation is common in maine coons and ragdolls with HCM?
MYBPC3 mutation
256
What is the hallmark sign of HCM?
Concentric LVH (diffuse, asymmetric, segmental) > 6mm in diastole
257
When on ECHO should you be assessing for HCM?
During diastole (Concentric wall >6mm)
258
HCM results in _______ dysfunction.
Diastolic dysfunction
259
What is HOCM?
HCM with LVOT obstruction with Systolic anterior motion of mitral valve
260
What is a classic finding on ECG for HCM?
Left anterior fascicular block = Negative QRS in leads II and III and Positive QRS in Lead I
261
What are the hallmark path findings in HCM?
Myofiber disarry and replacement fibrosis
262
What are the 4 main risks with HCM?
CHF (edema +/- effusion
ATE (risk increased with LAA size and smoke)
Arrhythmias
Sudden death
263
What are the mainstays in treatment for HCM?
Atenolol
Diltiazem
Antithrombotic (aspirin, Plavix, heparin)
264
What is the MOA of atenolol?
Beta Blocker, relative B1 specific
265
What is the MOA of diltiazem?
```
Ca channel blocker, blocks L-type Ca channels only
Varying selectivity (nodal>myocardium> vasculature)
```
266
What 3 animals get ARVC?
Boxers, bulldogs, and cats
267
What mutation is thought to occur with ARVC?
RYR2 (Ryanodine) receptor mutation - Affects Ca2+ release by SR
268
What are the 3 forms of ARVC?
Concealed, overt, systolic dysfunction
269
What are the classic findings on ECG for ARVC?
R sided VPC (Left BBB morphology) = UP in lead II
270
What can be seen on histopath for ARVC?
Fatty or fibrofatty replacement of RV +/- LV (epicardial to endocardial)
271
What is the treatment for ARVC?
Sotalol
Mexilitine and atenolol
Consider L-carnitine
272
What is aortic hypoplasia in boxers?
Relative aortic stenosis = arotic is relatively small, but no signs of SAS
Benign!
273
What disease has an early onset in Cavaliers?
MVD
274
Name 2 breeds that have polygenic threshold trait for MVD?
CKCS and Dachshunds
275
Is a cordiae tendoniae rupture compatible with long term survival?
Yes, MST 394 days
276
What is normal fractional shortening?
25-45%
277
What is normal LA:Ao ratio?
Less than 1.5
278
For MVD with is Stage A and what is recommended?
No disease = No tx
279
For MVD with is Stage B1 and what is recommended?
Insignificant MR (no LAE) = No TX
280
For MVD with is Stage B2 and what is recommended?
Significant MR (LAE) = No consensus reached
281
For MVD with is Stage C and what is recommended?
CHF
Acute: Lasix, pimo, sedation, nitroprusside
Chronic: Lasix, pimo, ACEi, diet
Avoid beta blockers
282
For MVD with is Stage D and what is recommended?
Refractory CHF
Diuresis
Aggressive afterload reduction
283
Furosemide needs to be where in order to work?
On the luminal side
284
Does pimobendan increased myocardial O2 demand?
NO
285
How is enalaril excreted?
Renal excretion
286
How is benazepril excreted?
Renal and biliary excretion
287
Which drug may prevent myocardial and perivascular fibrosis and has resulted in a 69% reduction in mortality in treated CHF dogs?
Spironolactone
288
Which breeds can get a juvenile form of DCM?
Dobermans and PWD
289
What are two metabloic causes of DCM?
Taurine (Cockers)
| Carnitine (Boxers)
290
What is a toxic cause of DCM?
Adriamycin
291
Why is taurine essential in cats?
Cats have less CSAD (cystine sulfinic acid decarboxylate) in order to form it
292
Where is the majority of L-carnitine stored in the body?
Almost 100% in cardiac and skeletal mm
293
What drug has been shown to improve survival in DCM dogs?
Pimobendan (130 days compared to 329 days)
294
What can be found in >75% of DCM affected dobermans?
Ventricular ectopy
295
What are the hallmarks of atrial fibrillation?
Irregular rhythm, no p waves, narrow QRS
296
What percentage of dogs will develop cardiac changes with adriamycin?
About 20% - Used dexrazozone (Zinecard)
297
What percentage of pulmonic stenosis was valvular?
About 90%
298
Why is it important to perform a coronary angiogram prior to balloon valvuloplasty in bulldogs?
Bulldogs can have R2A coronary anomaly that if ballooned would be fatal
299
What is the cause of SAS?
fibrocartilaginous ring
300
What is important to remember about the development of SAS?
Congenital BUT develops postnatally
301
In which breed is SAS polygenic?
Newfies
302
What is the tx for SAS?
Only transient improvement with valvuloplasty
| Atenolol and prophylatic abx
303
What does HARD stand for?
Heartworm associated respiratory disease in cats
304
What are common CS in cats with HWD?
Coughing, vomiting, sudden death 7%
305
Which biomarker has high sensitivity and specificity for myocaridal damage?
Troponin (isoform TnI)
306
What biomarker is increased in cats with HCM and CHF?
cTnI
307
In dogs, when have cTnI been increased?
```
Clinical and subclincial cardiac dz
Pulmonary hypertension
Pericaridal effusion due to HAS
Mycarditis with Babesia/Ehrlichia
Myocardial ischemic injury associated with GDV
Blunt thoracic and myocardial trauma
High dose of doxorubicin chemo
Oleander intoxication and snake bite
Increased age in dogs
Dogs with renal disease
```
308
When is BNP detected?
Released from ventricle in response to increaed wall tension and stretch
Released as prohormone = cleaved into active hormone BNP and inactive NT-proBNP
309
In dogs, when has BNP been found to be elevated?
Asymptomatic mod/sev MVD and CHF
Diagnosing heart failure in dogs with cough or dyspnea
Increased in severity of heart failure and may be used as tool to predict clincial outcome
310
In cats, when has BNP been found to be elevated?
Not effective in mild/mod HCM but good in sev HCM
Differentiate cardiac vs noncardiac causes of dyspnea in cats
Higher levels if in severe CRF
311
Which 2 dog breeds get SVT?
Labs and Boxers
312
What are 3 options to treat SVT?
1. Vagal maneuver
2. Fluid Bolus
3. Diltiazem
313
What type of bundle branch block is always associated with pathology?
Left Bundle Branch Block
