Veterinary Medicine - Cardiology Flashcards
What is the drug of choice for Ventricular Tachyarrhythmia?
Lidocaine
What are our 2 main beta-channel blockers?
Atenolol
Esmolol
What is the of main advantage of Esmolol? What’s it’s brand name (A hint for the first question)
Very short half life
“BreviBlock”
Potassium channel blockers can be used for what type of Tachyarrhythmia?
Both SVT & Ventricular!
What is our main Potassium channel blocker (And name the specific preparation for Dogs)?
Amiodarone (“Nexterone”)
What are the possible side effectsdisadvantage of Amiodarone
Very long half life
Interaction with thyroid gland (can cause hypo hyperthyroidism)
Can cause liver failure
What is our main Calcium-Channel Blocker?
Diltiazem
What is the antidote in case of Diltiazem overdose?
CaCl
What is the antidote in case of AtenololEsmolol overdose?
Glucagon
A patient presents with Ventricular Fibrillation. What are the first 2 counter-measures? (In order)
Defibrillator
AAD: Lidocaine or Amiodarone
What are the 2 categories of drugs that treat Bradyarrhythmias?
Parasympatholytics
Sympathomimetics
What are 2 Parasympatholytics that we use to treat Bradyarrhythmias?
Atropine
Glycopyrrolate
What are 2 Sympathomimetics that we use to treat Bradyarrhythmias?
Terbutaline
Theophylline
What are the 3 elements that define Atrial Fibrillation?
Irregularly-Irregular rhythm
Tachyarrhythmia
Absence of P-waves
What is the definitive treatment for Bradyarrhythmias?
Pacemaker
Atrial Fibrillation - 3 Drugs (of 3 different families) for treatment
Atenolol (Beta-blockers)
Diltiazem (Calcium-channel blockers)
Digoxin (Increases parasympathetic input on AVN + Positive Inotrope)
Atrial Fibrillation - What are our 2 avenues of treatment?
Drugs
Defibrillation
What is the semi-definitive treatment for AF? Explain the “Semi” Part
Defibrillation
Resets the abnormal pacemaker but temporary - Can last for a couple of hours up to a year
What’s the difference between Atrial Fibrillation and Atrial Flutter?
Fibrillation - Multiple abnormal atrial pacemakers (F-Waves may or may not be present)
Flutter - Single abnormal atrial pacemaker (F-Waves present)
What is the Systolic & Diastolic pressures of the right atrium?
8 / 0(3)
What is the Systolic & Diastolic pressures of the left atrium?
8 / 0(5)
What is the Systolic & Diastolic pressures of the right ventricle?
25 / 0
What is the Systolic & Diastolic pressures of the main pulmonary artery?
25 / 10
What is the Systolic & Diastolic pressures of the left ventricle?
120 / 0
What is the Systolic & Diastolic pressures of the aorta?
120 / 80
Giving vasodilators will necessarily decrease BP (TF). Explain
No
May remain unchanged or even increase! Systemic vascular resistance may decrease, causing cardiac output to increase
S3 & S4 Sounds - What are the physiological meaning if either of them exist?
Decreased compliance of the ventricle
S3 - Signifies…?
Loss of ventricle compliance in the early & passive stage of the diastole
S4 - Signifies..?
Loss of ventricle compliance in the late & active stage of the diastole
Jugular pulse signifies..?
Severe tricuspidal regurgitation
Jugular distension signifies…?
Dangerously high pressure in the right atrium
Split S2 - Gives clue to the presence of…?
Pulmonary hypertension
Jugular distension. What would make you think that the pathology isn’t a life threatening emergency at this very moment?
1) Distension goes up only up to distal third of jugular
2) Distension disappears on Inhalation
Positive Hepato-Jugular reflex - Signifies…?
Increased right atrial pressure
Pulsus Paradoxus - Describe what it means and what it signifies
Peripheral pulse strength intensifies on Expiration and weakens on Inspiration.
Cardiac Tamponade
3 DDs for Bounding Pulse
PDA
Aortic Insufficiency
3rd Degree AV-Block
What is a common and normal EKG finding regarding P and QRS waves that can be found in Cats?
Amplitude of P Wave > R Waves
Wandering pacemakers - Explain the physiology
During inspiration, blood has a much easier time entering the atrium, thus causing a reflex that causes an increase in heart rate - leading to Sinus Arrhythmia. At the same time - It causes the right atrium to fill with a larger volume of blood as compared to expiration - causing the atrium to expand - and thus the amplitude of the P-Wave is enlarged on EKG. The opposite happens on expiration - causing a cyclical change in P-Wave amplitude.
Mitral Regurgitation - What are the 2 possible complications of Jet Lesion?
1) Pericardial Effusion
2) Atrial septal defect (ASD)
Mitral Regurgitation - Describe the murmur on auscultation?
Left Apical - Systolic - Band\Plateau shape Murmur
Mitral Regurgitation - Common signalment. Also, which breed tends to develop the disease the youngest?
Middle age - Old, small breed dogs
Cavalier King Charles Spaniel
Mitral Regurgitation - History and Clinical signs
Exercise intolerance
Nocturnal restlessness
Chronic cough (Enlarged left atrium presses on the atrium)
Tachypnea, Dyspnea, Orthopnea
Pale mucus membranes
Weak peripheral pulse (Lack of perfusion)
Left apical systolic murmur
Syncope, Ascites, Peripheral edema, Jugular distension, Jugular pulsation (2nd Pulmonary hypertension)
Cardiac cachexia
Mitral Regurgitation - The quieter the murmur - the lower the severity of the disease (TF)
Not necessarily
In chronic disease - Atrial pressure can be so severe that it can barely receive any more blood \ Left ventricle lost ability to contract \ Both
Mitral Regurgitation - What are the 3 electrical abnormalities that can arise 2nd to MR?
Atrial fibrillation (AF)
Atrial premature complex (APC)
Ventricular premature complex (VPC)
Mitral Regurgitation - Vertebral Hearts Score (VHS) - Upper limit in Dogs and Cats?
Dogs - 10.5 times the length of T4
Cats - 8.1 times the length of T4
Mitral Regurgitation - Name all the possible radiological changes (First on DV, then Lateral)
DV:
L.Auricle bulges beyond the cardial silhouette
L.Ventricle enlargement
Increased opacity of the L.atrium
Lateral:
L.Atrial enlargement
Enlargement of the pulmonary veins and later in the disease the pulmonary arteries
Peri-hilar edema (Interstitial -> Alveolar)
Dorsal displacement of the left mainstem bronchi / Trachea
3 DDs for chronic cough in old small breed dogs
MR Tracheobronchomalacia
Tracheal Collapse
Chronic Bronchitis
Mitral Regurgitation - Treatment options
Pimobendan
ACE-i
Furosemide
Digoxin
Spironolactone
Mitral Regurgitation - According to the EPIC study, in which stage is it recommended to start treatment? Describe the stage and what is the treatment of choice?
B2
Moderate cardiomegaly without clinical signs
Pimobendan
Dilated Cardiomyopathy - Common etiologies
Genetic (Doberman Pinscher)
Taurine deficiency
Grain-free diet
Tachycardia-induced Cardiomyopathy (Large breeds)
Dilated Cardiomyopathy - Systolic Diastolic dysfunction
Systolic
Dilated Cardiomyopathy - Eccentric Concentric Hypertrophy
Eccentric Hypertrophy
Dilated Cardiomyopathy - Signalment
Middle age, Medium Large breed dogs
Dilated Cardiomyopathy - Doberman - The failure is on the leftright side
L-CHF
Dilated Cardiomyopathy - Large breeds - The failure is on the leftright side
R-CHF (Giant Dane Dog de Bordeaux)
Dilated Cardiomyopathy - Clinical Signs in large breeds
Syncope
Sarcopenia
Ascites
Jugular Distension
Positive Hepato-jugular
Tachyarrhythmias (e.g. AF)
Dilated Cardiomyopathy - Clinical Signs
Chronic cough
Dyspnea, Orthopnea
Exercise Intolerance
Low-grade Murmur
Cyanosis
Pulse Deficit
Dilated Cardiomyopathy - Possible X-ray findings
L.V. Enlargement
+- L.A Enlargement
Pulmonary Edema
Enlarged pulmonary vasculature
Ascites, Hepatomegaly (R-CHF)
Dilated Cardiomyopathy - Possible EKG findings
QRS Amplitude Increase (L.V. Enlargement)
APCs /AF (Large Breeds - Doge De Bordeaux)
VPCs \ VT
Dilated Cardiomyopathy - Treatment tenets + Specific drugs
Decrease AL : Pimobendan \ ACE-i \ Nitroprusside \ Hydralazine \ Amlodipine
Positive Inotropes: Pimobendan \ Dobutamine \ Digoxin
Decrease PL: ACE-i \ Furosemide
AAD: Digoxin \ Beta Blockers \ Calcium Channel Blockers
Dilated Cardiomyopathy - Prognosis
75% of Clinical dogs - 6 months MST
Hypertrophic Cardiomyopathy - Signalment
Cats - >1 year, any age
Predisposed breeds: Maine-coon, Ragdoll, British shorthair, Sphynx, Persian
Hypertrophic Cardiomyopathy - Systolic Diastolic Dysfunction
Diastolic
Hypertrophic Cardiomyopathy - Eccentric Concentric Hypertrophy
Concentric Hypertrophy
Hypertrophic Cardiomyopathy - Possible Clinical Signs
Open-mouth breathing
Tachypnea \ Orthopnea \ Dyspnea \ Abdominal expiratory effort
Acute hind limb\s paresis \ Plegia
Syncope
Hypertrophic Cardiomyopathy - Classic Radiological Findings
L.Atrial + R.Atrial enlargement (“Valentine-shaped heart”)
Hypertrophic Cardiomyopathy - Diagnosis
Pro-NT BNP
US: LA Enlargement + Hypertrophy of LV Aorta\LA ratio > 1.5
EKG
Hypertrophic Cardiomyopathy - Treatment
Pimobendan (If HOCM is ruled out)
ACE-i \Furosemide
Clopidogrel \Heparin \Rivaroxaban (Prevent thrombus formation)
Pulmonic \ Sub-Aortic Stenosis - Which is easier to identify on X-ray? What are the common findings of it?
Pulmonic stenosis
R.Ventricular enlargement
Main pulmonary artery trunk bulge
Pulmonic \ Sub-Aortic Stenosis - Treatment options
Beta \Calcium Channel Blockers
ACE-i +- Furosemide - In case of danger of CHF
Surgery /Catherization (only for Pulmonic stenosis)
Pulmonic \ Sub-Aortic Stenosis - Which can be catheterized?
Pulmonic Stenosis
Pulmonic \ Sub-Aortic Stenosis - How to differentiate? (Physical exam)
Weak Femoral Pulse - SAS
Normal Femoral Pulse - PS
Murmur radiating to the right side of the thorax as well - SAS
Pulmonic \ Stenosis / Sub-Aortic Stenosis- Classic EKG findings
Pulmonic stenosis:
Lead 1 - Negative QRS
AVF - Negative QRS
Sub-Aortic Stenosis:
Lead 2 - Increased QRS amplitude
Patent Ductus Arteriosus (PDA) - Auscultatory Finding
Left Basilar - Systolic + Diastolic - Band Shape Murmur
Patent Ductus Arteriosus (PDA) - X-ray finding
On DV:
Bulging of (From right to left):
Main pulmonary artery + Aorta + Left auricle enlargement (“Triad”)
L.V Enlargement +- L.A Enlargement
Patent Ductus Arteriosus (PDA) - EKG Finding
Increased QRS amplitude on lead 2
Patent Ductus Arteriosus (PDA) - Which side of the heart is affected most?
Left side of the heart
Pulmonic Sub-Aortic Stenosis - Auscultatory findings
Left Basilar - Systolic - Diamond shape (“crescendo-decrescendo”)
Patent Ductus Arteriosus (PDA) - Femoral pulse is? (Bounding Normal Weak)
Bounding
Patent Ductus Arteriosus (PDA) - Treatment modalities
Pimobendan + ACE-i \Furosemide
Surgery
Stenting
Ventricular septal defect (VSD) - Auscultatory finding
Right Apical - Systolic - Band \ Diamond Shape Murmur (Depending on the size of the defect: Band - big, Diamond - small)
Ventricular septal defect (VSD) - Treatment
Pimobendan
ACE-i \ Furosemide
Ventricular septal defect (VSD) - Which murmur is worse - Band/Diamond Shape?
Band shape (Bigger defect)
Explain Differential Cyanosis
When R-L shunt occurs - Mucosa of the caudal region (i.e. Genital mucosa) will suffer more from hypoxia and demonstrate worse cyanosis
Young dog with a right apical systolic murmur - DDs
Tricuspidal-valve dysplasia
Ventricular septal defect
Medium, large breed dog (young) presents with a Left Basilar - Systolic - Diamond-shape Murmur, followed by a Left Basilar - Diastolic - Decrescendo Murmur. What is the most probable diagnosis?
Aortic semi-lunar valve bacterial infection (Endocarditis) and acquired Aortic Insufficiency following congenital Sub-Aortic Stenosis
Spectral Doppler - What is the normal Ratio between the 2 diastolic phases?
E > A (1-1.7)
Spectral Doppler - What is the meaning of a severe increase in E/A ratio?
Severe decrease in ventricular compliance
Spectral Doppler - What is the use of E/E’?
Best evaluator of the diastolic function of the ventricles
M-Mode US - Equation of FS (Fractional Shortening)
FS = [ EDV - ESV / EDV ] x 100
FS (Fractional Shortening) - As the BW of the animal decreases - the FS…?
Increases
Large Breeds ~ 30%
Small Breeds Cats ~50-60%
Left-side - Volume overload - 4 DDs
Mitral valve dysplasia \ MMVD
VSD
Aortic Insufficiency
PDA
What is a disease that you should particularly worry about before anesthesia?
DCM
Add positive inotropes
*Other cardiac diseases of course also warrant consideration specifically be conservative with IV fluids
Pulmonic Stenosis - On auscultation can be easily confused with…? Why? (Not Sub Aortic stenosis)
ASD
Because it creates a “Pulmonic Stenosis-like” Murmur (Relative Pulmonic Stenosis due to excess blood flowing through the tricuspid valve)
Right side - Volume overload - 3 DDs
Tricuspidal valve dysplasia \ TR
ASD
Pulmonic Insufficiency
Left side - Pressure overload - 2 DDs
Sub Aortic Stenosis
HOCM
What are the 4 elements of Tetralogy of Fallot
1) VSD
2) Pulmonic Stenosis
3) RV Hypertrophy
4) “Overriding” Aorta
Right Side Pressure Overload - 3 DDs
Pulmonic Stenosis
Tetralogy of Fallot
R-L Shunting PDA
What are the characteristics of an Innocent Murmur?
Situational (Position / Stress..)
Short
Soft ( < III / VI )
Single
Small (Focal)
Systolic (Only)
Disappears until 4 months of age
Weakens over time
Typically left basilar
No associated clinical signs
MMVD Monitoring - What can we tell the owners to monitor at home to monitor deterioration/efficacy of treatment?
Sleeping Respiratory Rate
MMVD Treatment - By Stages
Stage A - No treatment needed. Monitor once a year
Stage B1 - (Murmur) - Enalapril
Stage B2 - (Cardiomegaly\Atrial Enlargement) - Pimobendan + Enalapril
Stage C - O2 \ Furosemide/ ACE-i \ Pimobendan \ Sedation. If indicated: Anti-tussives \ Anti-arrhythmic \ Bronchodilators
Stage D - Afterload Reduction => Amlodipine \ Nitroprusside. If indicated: Thiazides \ Sildenafil \ Anti-tussives \ Bronchodilators
When should you treat VPCs?
High number of VPCs per minute
Pairs\Triplets of VPCs
Multi-Focal \ Polymorphic
R on T Phenomenon
Clinical signs ( Lethargy, Syncope, Pulse deficits, Decreased BP)
