Block 3 Flashcards
When should you treat an arrhythmia?
When is leads to a hemodynamic instability (tachy or brady)
Do all arrhythmias need treated?
NO! Most do not!!
Can antiarrhythmic drugs be pro-arrhythmic/
YES!
Do no harm!!
How do we classify anti arrhythmic drugs?
Vaughan-Williams
How is the Vaughan-Williams classified?
By which channels are blocked
What are the 4 classes of Vaughan-Williams?
Class 1: Na channel blockers
Class 2: Beta-adrenergic blockers
Class 3: K channel blockers
Class 4: Ca channel blockers
What is phase 0 of the cardiac cycle?
Rapid depolarization in cardiac muscle cells
What do sodium channel blockers od?
Slows the rapid depolarization in cardiac muscle cells (Phase 0)
What sodium blockers are used to treat ventricular arrhythmias?
Lidocaine, procainamide, mexiletine
What sodium blocker is used to treat atrial fibrillations in horses
Quinidine
What does vagolytic mean?
Increase heart rate
What is quinidine used for?
Converts A-fib to sinus rhythm in horses with lone a-fib
What is procainamide used for?
Therapy for ventricular arrhythmia
How is lidocaine given for treatment of arrhythmias?
IV
What type of treatment is lidocaine used for (chronic or acute)
Acute
What type of arrhythmias does lidocaine treat?
Ventricular arrhythmias
How is mexiletine adminsitered?
Orally “oral lidocaine”
What is mexiletine used for?
Chronic therapy of ventricular arrhythmias
What do beta-blockers do?
Slows the Ca in phase 2
What are beta blockers for?
Negative inotropes (reduce HR)
What phase do beta blockers inhibit?
Phase 2
When should you treat arrhythmias?
Can lead to hemodynamic instability (tachyarrhythmias or bradyarrhythmias)
What are 2 examples of tachyarrhythmias?
Ventricular arrhythmias
Supreventricular arrhythmias
What are typical bradyarrhytmias?
AV blocks or persistent atrial standstill
Seems like tachyarrhmias are ventricular and bradyarrhymias are atrial
Do ALL arrhythmias need treated?
NO!! Many do not!
What can anti-arrhyhic drugs cause?
They can potentially be pro-arrhythmic
What does A-fib drive?
Congestive heart failure
What is the most common drug classification called?
Vaughan-Williams
How does the Vaughan William classification classify drugs?
Which channels/currents the drugs block
What is class 1 of the Vaughan Williams?
Na channel blockers
What is class 2 of the Vaughan Williams?
Beta-adrenergic blockers
What is class 3 of the Vaughan Williams?
K channel blockers
What is class 4 of the Vaughan Williams?
Ca channel blockers
What are the 4 phases of heart depolarization and depolarization?
Stage 0 - Depolarize with Na channels open
Stage 1 - Initial depolarization. Na channels close and K channels open
Stage 2 - Plateau. K stay open and Ca open
Stage 3 - Rapid repolarization. Ca close and slow K open
Stage 4 - Resting. High K permeability
What phase do class 1 drugs block?
Stage 0
Slows rapid depolarization of cardiac cells
What are the 4 class 1 drugs we need to know?
Quinidine
Procainamide
Lidocaine
Mexiletine
What does quinidine do?
convert A-fib to sinus rhythm in HORSES w/ lone a-fib
What is a side effect of quinidine?
Vagolytic (can increase HR)
What does procainamide do?
Therapy of ventricular arrhythmias
How is lidocaine given for arrhythmias?
IV
What is lidocaine given for?
ACUTE treatment of life-threathening arrhythmias
How is mexiletine given?
Orally
What is mexiletine for?
Chronic therapy of ventricular arrhythmias
What are class 2 vaughan williams?
Beta blockers
What phase of depolarization block?
Phase 2
What is the purpose of class 2 beta blockers
blocks funny currents (nodal cells)
What do beta blockers do?
Negative inotrope
Reduce contractility (slows Ca intake)
What is the biggest beta blocker that is used?
Atenolol
How does atenolol help?
Cardioprotective
What beta is atenolol most selective for?
Beta 1 specific
What is atenolol used for?
Obstructive lesion (SAS, PS, HOCM)
What chamber does atenolol mostly act on?
Atrial arrhythmias
Occasionally ventricular arrhythmias
What’s the biggest side effect of atenolol?
Bradycardia (negative ionotrope)
What phase does class 3 block?
Stage 3
Potassium repolarization
What are the 2 main class 3 drugs?
Sotalol
Amiodarone
What is something else sotalol acts on besides potassium blockers?
Beta blocker
***What is the most common drug used for chronic management of ventricular arrhythmias?
Sotalol
What are 2 side effects of sotalol?
Pro-arrhythmia
Negative inotrope
What properties does amiodarone have?
Has properties from all vaughan Williams classes
What is amiodarone used for?
Refractory ventricular arrhythmias
What is a concern of amiodarone?
Has many side effects
Likely because it acts on so many different channels
What stage does class 4 Ca blockers act on?
Stage 2 (plateau)
What is the main goal of class 4 drugs?
Block the AV node
What is the main class 4 drug?
Diltiazem
What does diltiazem do?
Treats atrial arrhythmias through blocking AV node
What is the first line drug for rate control of atrial fibrillation?
Diltiazem
What are the side effects of diltiazem?
Negative inotrope
Hypotension
What are 2 downsides to the Vaughan-Williams scheme?
Doesn’t explain all mechanisms of each drug
Doesn’t include all antiarrhytmic drugs
Explain Digoxin
positive inotrope
Slows conduction of AV node
Controls A fib
Slows NA/K ATPase
What needs to be monitored with digoxin?
Pro-arrhythmic
GI side effects
What does torsade de pointe mean?
Turning around the point
Common arrhythmia in horses
What is used to treat to torsade de point?
Magnesium sulfate
What type of arrhythmia is torsade de pointe?
Refractory ventricular arrhythmia
What is the acronym for aims of treatment of heart disease?
D - delay of disease progression
I - Improve quality of life
P - Prolong survival
P - Prevent catastrophic event
How can you help determine if a cat’s murmur is present?
Stress test
When using atenolol, what are the 3 questions that you should ask?
- Is disease clinically relevant or prognostically important
- Can I follow-up?
- Is treatment safe?
what are drugs that affect ventricular pumping?
Inotropes
what needs to be used in conjunction with diuretics?
Sodium restriction
ACE-inhibitors
In refractory heart disease with chronic fluid retention, what is a good diuretic to use?
Torasemide
What diuretic is used in acute cases?
Furesemide
What diuretic is used in chronic cases?
Torasemide
What is a weak diuretic that is also a cardio protectant?
Spironolactone
What is spironolactone used in conjunction with sometimes?
Furosemide
What is a diuretic that is not a loop diuretic that can be used in conjunction with torasemide or furosemide?
Hydrochlorothiazide
What are the 5 diuretics?
Furesemide
Torasemide
Spironolactone
Hydrochlorothiazide
Why must an ACE inhibitor be used with diuretics?
Use of diuretics will initiate a strong RAAS response
What should DCM in cats always be treated with?
Taurine
What is the only nutraceutical that has been shown to help cardiac cachexia
Omega-3 fatty acids
What are the 4 ACE-inhibitors?
Benazepril
Enalapril
Lisinopril
Ramipril
What do ACE-inhibitors do?
Inhibit RAAS system be decreasing effectivity of Angiotensin II
What are 2 nitro-vasodilators?
nitroglycerine ointment and sodium nitroprusside
What is a non-nitro-vasodilator?
Hydralazine
What drugs help to treat pulmonary hypertension?
Phosphodiesterase-5 inhibitors
What is a phosphodiesterase-5 inhibitor?
Sildenafil (viagra)
What is the drug of choice for systemic hypertension?
Amlodipine
Amlodipe is a calcium channel blocker
What do angiotensin receptor blocking agents do?
Block RAAS
What is a common RAAS?
Telmisartan
When should you not treat HCM?
When there is low risk / asymptomatic
When should you consider an anticoagulant/antiplatelet?
With severe left atrial diameter (will throw a clot) >20mm
Risk factors for HCM are LA enlargement, LV diastolic dysfunction
What should be considered with LV diastolic dysfunction?
Furosemide
What should be considered with LV remodeling (regional wall thickening)
ACE inhibition and Plavix (anticoagulation)
What should be considered with LV systolic dysfunction?
Pimobendan
Furosemide
ACE inhibition
Plavix
What should be considered with extreme LV hypertrophy?
Diltiazem
Atenolol
What should be considered with Ventricular ectopy?
Sotalol
Atenolol
Amiodarone
What should be considered with A fib?
DILTIAZEM
What is the acute treatment of heart disease acronym?
F - furosemide
O - oxygen
N - nitroglycerine paste
S - sedation
T - tap (pleural effusion)
What do antiarrhythmics do?
Cardio-depressive
What is a sign of CHF?
Pericardial effusion
What are the main aims of ATE?
Pain management
Induction of hypo coagulable state
Prevention of thrombus expansion
What should be given for pain in ATE?
Full mu opioid
What can be given to prevent thrombus expansion?
Heparin
What can be given to inhibit platelet aggregation?
Plavix
Besides plavix, what can be added to help with ATE management/prevention?
Aspirin or rivaroxaban
What is B1 stage of most cardiac diseases?
Normal LA/LV size or mild enlargement
Where will MMVD be auscultated?
Left apical systolic murmur
Should you treat a B1 MMVD?
No
What should you do about a B1 MMVD?
Monitor with auscultation and imaging
What does B1 MMVD not meet?
EPIC criteria
What was the result of the EPIC study?
15 month benefit if given pimobendan
What puts a dog in B2 for EPIC?
LA:Ao > 1.6
VHS > 10.5
What if a patient can’t have an echo to grade B1 or B2?
Chest rads
What do the chest rads need to be to categorize B1 or B2?
VHS < 10.5 = B1, no pimo
VHS > 11.5 = B2, pimo
VHS between is grey zone
What does categorization into B2 mean?
B2 = Start Pimobendan!
What does the C in the grading scale stand for
C = CHF (left sided in DMVD)
What should usually be done when presented with a potential cardiac case?
Blood pressure!!
What is the prevention for all stages of the EPIC rankings?
None (no way to prevent)
What does stage D mean of DMVD?
Refractory / end stage
Mini Schnauzers are very susceptible to MMVD
What can you also consider if a dog is in the “grey zone” with VHS?
VLAS
What is VLAS?
Vertebral left atrial size
What does VLAS usually need to be over for B2?
2.4 (or 3.0)
What should you add on to pimobendan in “very advanced” B2?
RAAS inhibitor
What is the mechanism of ACE inhibitors?
Block enzyme that turns angiotensin I into angiotensin II
When should you recheck B2 dogs?
every 6-12 months
Will giving furosemide kill a dog?
No, give it if suspicious
What effect does nitroglycerine have?
Vasodilator
What is the chronic treatment for MMVD acronym?
P - pimobendan
A - ACE inhibitor
S - spironolactone
F - Furosemide
E - Exercise restriction
What 2 things does pimobendan do to help CHF?
Vasodilator
Positive inotrope
What is the median survival time after stage C onset?
CHF = 1 year
Will all dogs with MMVD develop CHF?
No only 25-30%
What is lasix?
Brand name of furosemide
How do you treat pulmonary hypertension associated with DMVD?
Diuretics to reduce LA pressure
What are the 3 potential DMVD complications?
Pulmonary hypertension
Arrhythmias
Left atrial tear
What type of arrhythmias can be seen with DMVD?
A-fib
Does MMVD occur in cats?
No
Degenerative valve disease occurs in horses but not a common cause of mortality!
No proven treatment but if CHF develops, poor prognosis
***What types of drugs treat secondary Afib?
“Rate control drugs”
What is the most common shunt?
VSD
What are the 3 most common shunts?
PDA, VSD, ASD
What is clinical hallmark of PDA?
Loud continuous heart murmur (machine murmur)
What are the 2 different managements for PDA?
Interventional occlusion and surgical ligation
The interventional occlusion is the coils and stuff
What is the weird pear shaped coil called?
ACDO
Is PDA curable?
Yes!
Can you do PDA in really small animals?
No
What is the disadvantage to surgical ligation of PDA?
Rupture can happen and kill dog
Is PDA heritable?
Yes
What does a reverse PDA look like?
Pink oral mm
Cyanotic vaginal mm
What is there to be done about a reverse PDA?
Not much
Potentially repeated phlebotomy
Where is the murmur herd on a VSD?
On the right (systolic)
What is the most common VCD?
Perimembranous
If there is a small VSD, what is the lifespan of the dog?
Normal lifespan
What is Eisenmenger’s complex
shunt reversal
Is VSD heritable?
Yes!
How to treat VSD?
Can add device
Start on enalapril and spironolactone
Are there murmurs with ASDs?
No
Where is the dilation associated with ASD?
In RA and RV
Is ASD heritable?
Yes
What are the treatment options for most ASDs?
No therapy, just watch
What are treatment options for large ASDs?
Medical, surgery, interventional
What is medical treatment of ASD?
Enalapril and spironolactone
How can you treat ToF?
Exercise limitation
Propranolol (beta blocker)
Potentially phlebotomy
What is cause of sinus bradycardia?
NO Treatment
Find underlying cause
What is a first degree AV block?
Prolonged PR interval
No blocked P wave
What is a 2nd degree AV block?
Blocked P wave
What is a 2nd degree Mobitz type I AV block?
Gradual prolongation of the PR interval then a blocked P wave
What is a 2nd degree Mobitz type II AV block?
Consistent blocked P wave, consistently high grade (more than 2 dropped P in a row)
What is a 3rd degree AV block?
Complete AV dissociation
What of the blocks are a result of high vagal tone?
1st and 2nd degree type 1 Mobitz
What of the blocks are a result of conduction disease?
2nd degree type II Mobitz and 3rd degree
Are the high vagal tone blocks treatable?
NO!
What should you do if you are uncertain if the disease is related to high vagal tone or if its a conduction disease?
Atropine response test
If the animal becomes tachycardia off the atropine response test, what does this mean?
Positive test
What is the treatment for the 2nd and 3rd degree AV blocks?
Artificial pacemaker
What are the 4 things seen in an atrial standstill de to hyperkalemia?
Absent P waves
Bradycardia
Tented T waves
Widened QRS
How do you treat hyperkalemia?
Calcium gluconate
What is sinus arrest?
Sinus node fails to fire resulting in pauses of the rhythm
Sick sinus syndrome = idiopathic degeneration of sinus node
How do you treat sinus arrest?
High vagal tone likely doesn’t need treatment but atropine / glycopyrrolate if needed
What is sick sinus syndrome?
Fibrotic changes to the SA node
Causes syncope
What is treatment for sick sinus syndrome?
Pacemaker
Chronotropic drugs may help
Which sex gets sick sinus syndrome more?
Females!!
What is the medical treatment for sick sinus syndrome?
Theophylline
Propantheline
Terbutaline
Hyoscyamine
What is atrioventricular block caused by in cats?
Older cats - idiopathic fibrosis - usually asympomatic
Are pacemakers a good treatment for AV blocks?
Treats syncope but doesn’t change survival time
What are the 2 differentials for absent P waves?
A fib
Atrial standstill
What is heart speed of a fib patients?
Tachy
What is heart speed of atrial standstill patients?
Brady
What is atrial standstill patients usually associated with?
Hyperkalemia
What are the 4 target organs of hypertension?
Brain
Eyes
Kidneys
Heart
At what BP will organ damage begin for the eyes?
> 160
What are 2 signs of damage to the eyes?
Blindness
Medriasis
What is a result to the heart of systemic hypertension/
LV hypertrophy
How should you treat systemic hypertension?
Take 2-5 days to reduce below 160. Need to give time to equilibrate to it
Should you hospitalize a systemically hyerptensive patient
No, too stressful
What drug should be given to treat systemic hypertension?
Amlodipine
How long after starting amlodipine should there be a recheck?
3 months
What are 2 drugs that can be used as add-ons to amlodipine?
Telmisartan
Benazepril
What is the goal of a hypertensive emergency (<200 + organ damage)
Reduce by 10% in first hour then 15% over next 3 hours
What is a drug that can be used in a hypertensive emergency?
Fenoldopam
What are 2 other drugs that can be used in hypertensive emergencies?
Hydralazine and sodium nitroprusside
What is pulmonary hypertension?
> 40mmHg
What is cor pulmonale?
Enlargement of right side of heart due to high pressure in lungs
What are 3 overarching treatment goals of pulmonary hypertension?
Correct underlying cause
Decrease pulmonary vascular resistance
Increase RV cardiac output
How do you decrease pulmonary vascular resistance?
Vasodilators
-oxygen acutely
PDE-5 inhibitors (Viagra, cialis, sildenafil)
How can you increase RV output?
Pimobendan
What do you NOT give in pulmonary hypertension?
Ferosimide
What is type A in pulmonary stenosis?
Fusion
What is type B in pulmonary stenosis?
Dysplasia
Is there a treatment for type A pulmonary stenosis?
Yes
Is there a treatment for type B pulmonary stenosis?
No
What is the most common consequence of pulmonary stenosis?
Sudden death
What can be done for pulmonary stenosis?
Exercise restriction
Selective B blockers (atenolol)
Balloon angioplasty (surgery)
Is pulmonary stenosis hereditary
yes
What is the number that determines the severity of sub aortic stenosis?
Pressure to open aortic valve
120/10 -> 200/25
What can happen commonly with a sub aortic stenosis?
Infective endocarditis
What can be done for sub aortic stenosis?
Exercise restriction
Beta blocker (atenolol)
Prophylactic antibiotics to reduce risk of infectious endocarditis
Does canine sub aortic stenosis balloon valvuplasty work well?
Not really
What can be done about semilunar valve stenosis?
Exercise intolerance
Atenolol (prevent tachycardia)
Drugs to manage CHF (Ferosemide, pimobendan, emalapril, spironolactone)
When does cyanosis occur?
Pa02 < 40mmHg
What muscle is called the “heave line” that is a result of chronic respiratory distress?
External Oblique
Where is a tracheotomy inserted?
Ventral neck and a horizontal incision between tracheal rings. In the upper third of the neck
What 2 main things are needed for respiratory emergencies in the field?
Tracheostomy tube
Ultrasound
How do you know when to add a tracheostomy?
In the case of respiratory distress with noise
What is another reason for needing a tracheostomy?
Tracheal collapse
Esophageal obstruction (choke)
What type of horse is at an increased risk for needing a tracheostomy?
Horses that are homozygous for HYPP leading to pharyngeal pathology
Name the 3 most common lower respiratory conditions in horses
Pneumonia / pleuropneumonia
Pulmonary edema
Equine asthma
What is pulmonary edema usually secondary to?
Cardiogenic
What are symptoms of a horse with pulmonary edema?
Fluid from nose (clear to pink)
Cough
How do you treat pulmonary edema?
Oxygen and lasix
How do you diagnose pneumothorax?
M-mode ultrasound
Use kitchen cling wrap to pack it? idk
How do you diagnose hemothorax?
Swirling on ultrasound
What happens to body weight of horses with asthma?
Lose weight quickly
What 2 drugs are added as medical treatment of equine asthma?
Bronchodilator
Steroid (dex)
Nonrespiratory causes of respiratory distress?
Anemia
Red maple toxicity (O2 exchange)
Pain
Hyperthermia
Anhidrosis
What should you NOT do with horses that are in respiratory compromise?
AVOID SEDATION (alpha 2)
How do you determine if respiratory compromise is coming from upper vs lower tract?
Upper = noise
Lower = no noise
What is the cutoff for hypoxia?
<96%
What is the difference between stridor and stertor?
Stridor = high pitched
Stertor = low pitched
What sound is made with obstruction?
Stridor
What is lar par also called?
GOLPP
What is the definition of hypoxia?
Oxygen in tissue is low
What is the definition of hypoxemia?
Low oxygen in arterial blood
What is a greater respiratory response, hypercapnia or hypoxemia?
Hypercapnia
What should you do first with a respiratory patient?
Hands-off non invasive approach and assess them in an O2 cage
What should be first step in treatment of respiratory case?
Oxygen
What should be second step in treatment of respiratory case?
Sedation
Butorphanol or ace
How do you distinguish rhinitis from other nasopharyngeal differentials?
It is bilateral (most others are unilateral)
What can you do for laryngeal treatment?
Dexamethasone
Ice pack
Slow wake up with sedation
What is something important that you should minimize with laryngeal disease?
Barking
What will a tracheal respiratory disease sound like?
Cough is dry/honking
If cough is on inspiration:
Extra-thoracic tracheal disease
If cough is on expirationL
Intra-thoracic tracheal disease
What is herd on auscultation of a bronchial disease?
Expiratory wheeze
What do you see with bronchial disease?
Abdominal effort
What are top 2 differentials for bronchial disease?
Asthma
Bronchitis (infectious / inflammatory)
What are 2 bronchodilators that can be used for bronchial treatment?
Albuterol
Terbutaline
How many B lines must you see in a plane for it not to be normal?
> 3
When do you see paradoxical breathing?
Diaphragmatic pathology
What is paradoxical breathing?
Inspiration = abdomen sucks in
Expiration = abdomen distends
What should you do with diaphragmatic pathology?
Elevated position
Thoracocentesis is life saving
What is NIPD?
Non-infectious pulmonary disease
What are NIPDs?
Inflammatory or fibrotic
How does an NIPD occur?
Reaction to an environmental factor or abnormal response to injury
What are the 4 NIPDs?
Canine chronic bronchitis
Feline asthma
Eosinophilic bronchopneumonopathy
Idiopathic pulmonary fibrosis
What are the 4 goals for CCB?
Reduce inflammation
Control cough
Improve exercise tolerance
Slow progression
How can you reduce inflammation?
Environmental cleaning (smoke, aerosols)
What is a medical way to reduce inflammation for the chronic inflammation
Prednisone - cheap
Fluticasone - Inhaled but expensive
How do you control cough in the chronic bronchitis?
Hydrocodone
What is a side effect of hydrocodone?
Sedation
What is the number one way to improve exercise tolerance for CCB?
Manage obesity
How can you slow progression of CCB?
Prednisone and fluticasone
What is the prognosis of CCB?
Its progressive. Goal is to slow it, manage client expectation
What likely causes feline bronchial disease/? Aka feline asthma
likely allergen induced
Can you stop treatment of feline asthma if asymptomatic?
No!!
What are 3 goals of feline asthma?
Reduce inflammation
Slow progression and remodeling
Control bronchoconstriction
How do you reduce inflammation of feline asthma?
Environmental management
Glucocorticoids (fluticasone and pred)
***What is a side effect of pred on cats?
Diabetes mellitus in fat cats
Slowing progression and airway remodeling is same treatment as reducing inflammation
How can you control bronchoconstriction acutely for feline asthma?
Albuterol
SQ terbutaline
What is EBP?
Eosinophilic bronchopenumonopathy
What is EBP tho?
Idiopathic inflammatory disease in DOGS
How do you treat EBP?
Immunosuppressive steroids
What species gets ICPF?
West Highland White Terriers
What is ICPF?
Idiopathic canine pulmonary effusion
How do you treat ICPF?
No effective treatment
Can try steroids to reduce cough
Terminal
What is relapse rate of EBP?
30%
What can eosinophilic bronchopneumonopathy look like?
Lung worms
Give antithelmitic on top of steroids just in case
What is the cutoff for transudate?
<2.5
What is the cutoff for modified transudate?
2.5-7.0
What is the cutoff for exudate?
> 7.0
What is the first thing you do if your patient comes in with fluid in its chest?
Stabilize - oxygen and sedation
What do you do after stabilization?
Thoracocentesis (maybe imaging next)
Where is the first place you should look if the fluid is a modified transudate?
Heart
If it is a pyothorax in a cat, what is the most likely etiology?
Cat bite (pasteurella multocida)
If it is a pyothorax in a dog, what is the most likely etiology?
Inhaled plant piece (nocardia asteroids)
What is the medical treatment for pyothorax?
Broad spectrum antibiotics
(Amoxi + Clav) for 4-6 weeks
What is a surgical thing you can do for pyothorax?
Placement of chest tube
Also removal of FB in dog
What is the cutoff for chylothorax?
Triglycerides 2x serum or >100mg/dL
What is treatment for chylothorax?
Treat underlying cause
Chyle is very irritating to pleura
What is a Medical approach to chylothorax?
Low fat diet
What should you always ask before tapping a hemothorax?
Any rodenticide exposure
What should you always check before tapping a hemothorax?
Check PT/PTT BEFORE tapping chest if hemothorax is suspected
What are the BIG 5 parasites?
Nematode
Protozoa
Cestode
Trematode
Ectoparasite
What drug class works for giardia?
Benzimidazole (fenbendazole)
What drug class works for blood suckers and burrowing ectoparasites?
Macrocyclic lactones
Do tetrahydropyrimidines work against heart worm?
NO!!
Within microcytic lactones, what are 2 classes?
Avermectin and milbemycins
What drug class is within avermectin
ivermectin
eprinomectin
selamectin
What are 2 drugs within benzimidazole?
Fenbendazole
Albendazole
Do benzimidazoles more against HW?
NO!!
What are 2 drug classes within tetrahydropyrimidines?
Pyrantel
Strongid
What do preventative for HW act on?
L3 and early L4
What do mosquitos pick up from host?
microfilaria
What stage does microfilaria get to in mosquito?
L3
How long does going from microfilaria to L3 take?
10-14 days
What is the medical term for HW?
Dirofilaria immitis
What is tracheal collapse most commonly seen in?
Middle-aged to older toy and miniature breeds
When does the trachea collapse? Inspiration or expiration?
Expiration
What is the classic sound of a tracheal collapse?
Goose honking
what is the medical treatment for tracheal collapse?
Anxiolytic drugs, sedation
Cough suppressants (hydrocodone) and anti-inflammatory steroids (prednisone if needed)
What does a positive intrope do?
Makes heart beat stronger
When are 5 times to use a positive inotrope?
Impaired systolic function
Dilated cardiomyopathy
Heart failure (cardiogenic shock)
Critical care patients (septic shock)
General anesthesia
Drug overdoses
What type of drug is anesthesia?
Negative inotrope (postive inotrope helps to combat this)
What is the mechanism of action of positive inotrope?
Increase Ca influx into myocytes
What is the mechanism of action of digitalis catecholamine positive inotopes
Inhibit Na/K ATPase, activating Na/Ca
What is the mechanism of action of catecholamine positive inotropes
Stimulate beta-adrenoreceptors
Give an example of digitalis glycosides?
Digoxin
Give an example of catecholamines
Dobutamine
What is the mechanism of action of calcium sensitizers (PDE III inhibitors)?
Sensitive contractile filaments to Ca
Give an example of calcium sensitizers
Pemobendan
What is the drug of choice for cardiogenic check?
Dobutamine
What nerve type does norepinephrine work on?
Alpha 1
What does norepinephrine (alpha1) cause?
Vasoconstriction
What is the drug of choice for cardiac arrest?
Epinephrine
What does pimopendan do to the vessels?
Vaso dilator (both arterial and venous)
What type of “trope” is pimopendan
Strong positive inotrope + mixed vasodilator
How does pimobendan compare to dobutamine?
Pimobendan is longer and stronger but takes longer to kick in than dobutamine
When do you use pimobendan?
In dogs with congestive heart failure
How does the vasodilation aspect of pemobendan help with CHF??
Vasodilation helps to unload the failing ventricles but also helps increase contractility of heart
What is the mechanism of action of digoxin (review)
Plugs Na/K ATPase channel leaving more intracellular sodium for Na/Ca to utilize (increasing intracellular calcium)
What are 2 other effects of digoxin (digitalis glycosides)?
Baroreceptor (Increase vagal tone)
Antiarrhythmic
What is the major indication for digoxin?
Control A fib
When are the “trough levels” of digoxin?
8-12 hr post pill
***What factor can induce digoxin toxicity?
Hypokalemia
Where is digoxin primarily excreted?
Kidneys (not liver)
What drug do you need with increased preload?
Diuretics
Get that shit outta here
What is the main indication for diuretics?
CHF
What is the main loop diuretic to know?
Furosemide
What type of diuretic is hydrochlorothiazide?
Thiazide
What is the mechanism of action of thiazide?
Inhibit Na and H2O in distal tubules
What is the best/fastest/easiest diuretic?
Furosemide
What is an important beneficial aspect of spironolactone?
Spares potassium
Cardioprotective
Why might you eventually need to add an additional diuretic?
Eventually there will be a diuretic resistance that develops
What are the beta blockers known as?
The lols
What do beta blockers do?
Decrease contractility (negative inotrope)
Decrease myocardial oxygen demand
What beta receptors do atenolol (**) and metoprolol target?
Beta 1
What beta receptors does propranolol target
Beta 1 and 2
What are the side effects of beta blockers?
Bradycardia
Hypotension
Decreased systolic function
What are 3 indications for beta blockers?
Hypertrophic obstructive cardiomyopathy
Pulmonary/aortic stenosis
Antiarrhythmic effects
What beta blocker is preferred in cats?
Atenolol
What beta blocker is preferred in dogs?
Sotalol
If cannot do echocardiography, do not use beta blockers
Never use beta blockers in a “wet” patient - CHF
What is another negative inotrope and vasodilator?
Calcium channel blockers
What is the major effect of non-dihydropyridines? (Calcium channel blocker)
Nodal tissues
What non-dihydropyridine is most commonly used?
Diltiazem
What dihydropyridine is most commonly used?
Amlodipine
What is amlodipine mostly used for?
Treatment of systemic arterial hypertension
When do you use calcium channel blockers?
Atrial tachycardias (A fib!) or systemic hypertension
What are 4 drugs used for cardio protection?
ACE inhibitors
Beta blockers
Spironolactones
Fish oils
What is the main trigger for ACE inhibition?
Reduced cardiac output
What are the ACE inhibitors?
The -prils
Enalapril
What do ACE inhibitors do?
RAAS inhibitors and mixed vasodilators
Lower blood pressure!
What are the angiotensin receptor blockers?
The -tans
Telmisartan
What is telmisartan primarily used for?
Cats with proteinuria and systemic hypertension
What are angiotensin receptor blockers used for?
Lower blood pressure
What are prothrombin drugs used for?
Cats at risk of feline arterial thromboembolism
What does a cat have that may show rick of FATE?
Smoke
What are 2 FATE drugs?
Aspirin and Plavix
Is pemobendan used in cats?
Rarely
What are 2 drugs that can be used for treatment of Afib?
Digoxin
Diltiazem
Sorry - What are 6 dietary modifications to be recommended to CHF patients?
Sodium restriction
Fatty acids
Taurine (cats ony)
L-carnatine
CoQ10
Avoid BEG diets
Where should you not give fluids in a shock patient?
SQ or enteral
What fluid should you never give a shock patient?
Hypotonic fluids!
When do you give hypertonic solution?
In severe shock
What is the physical exam point that is the “last to go, first to come back”?
Blood pressure
What do you do if there is no response with shock fluids?
Consider a positive inotrope
Maybe issue is cardiogenic
What 2 dogs get DCM the most?
Boxer
Doberman
What are 3 drugs for treatment of DCM?
Pimobendan
Enalapril (cardioprotective)
Spironolactone (cardioprotective)
When do you add furosemide?
In CHF. DCM is not CHF
What are seen commonly in dogs with DCM?
Ventricular premature complexes (VPCs)
What drug is given to reduce arrhythmias in arrhythmegonic RV cardiomyopathies?
Sotalol
How do you determine if something is in CHF and not just DCM>
Has ascites and or a respiratory component
What do you give the patient that has DCM with CHF?
Furosemide
On top of everything else
What can you try with a patient that has lone Afib?
Electrical cardioverion (electric shock thing)
What are 2 drugs to correct Afib
Diltiazem
Digoxin
Besides Afib, what other disease do you see an absence of P waves?
Atrial standstill
What is given for a dog with atrial standstill?
Need a pacemaker
What other drugs do you give a dog with atrial standstill?
Still pimobendan
Enalapril (cardioprotectant)
Spironolactone (cardioprotectant)
What is the most important congenital pericardial disorder?
Peritoneaopericardial diaphragmatic Hernia (PPDH)
Do PPDH always need treated?
No, often incidental finding
What is treatment for PPDH?
surgical
What is the number 1 differential diagnosis for pericardial effusion in dogs?
Neoplastic
What type of fluid is in pericardium of heart failure patients?
Transudate
What is the most common cause of pericardial effusion in cats?
CHF
How do you treat pericardial effusion from CHF in cats?
No pericardiocentesis
Just use diuretics
What are the top 2 neoplasias that cause pericardial effusion in dogs?
Hemangiosarcoma
Chemodectoma
***What is treatment of cardiac tamponade?
PERICARDIOCENTESIS
Where do you approach for a pericardiocentesis?
Right side in cardiac notch
What will happen if you dont perform the pericardiocentesis?
The dog will die
What should you NOT give in pericardiocentesis?
Furosemide! NOOOOO
What should you give during preparation for pericardiocentesis of a cardiac tamponade case?
IV fluids
Maintain BP while prepping.
Also opioid for sedation (butorphenol)
What surgery can be done to treat continued cardiac tamponade?
Pericardectomy
In horses, what 2 places can you palpate for peripheral pulses in a shock patient?
Facial artery
Transverse facial artery
What happens to lactate with decrease lactate?
Increase lactate
What happens to lactate with strangulating lesions?
Higher base lactate than horses but lactate doesn’t change with strangulation lesions
What are the 6 catergories of shock?
Metabolic
Hypoxemic
Cardiogenic
Hypovolemic
Obstructive
Mal(distributive)
What is the most common type of shock?
Hypovolemic
How do you treat a guttural pouch mycosis?
Intra-arterial coil embolization
What can you give during maldistributive shock?
Epinephrine to cause vasodilation
What is number one reason for cardiogenic shock?
CHF
You basically give fluids to all types of shock in horses. What type do you NOT GIVE FLUIDS?
Cardiogenic!
How do you (not) give fluids during shock
Only IV
Not enteric, SQ, rectal
Treating shock, how much do you initially bolus with isotonic crystalloids?
10-20mL over 20-30 min then reassess
Treating shock, how much do you initially bolus with hypertonic saline?
2-4mL/kg
How much blood volume is required to require shock resuscitation in a horse?
> 30%
What drug classes are bronchodilators?
Sympathomimetics (beta agonists)
CNS stimulants
Adenosine antagonists
Bronchodilators occur due to which agonist?
Beta 2 agonism
What drug helps with lar par?
None, its a surgical disease
When should you administer oxygen to a patient in respiratory distress?
Always
What is persistent pulmonary hypertension?
Failure of fetus to make respiratory and cardiac transition to extra-uterine life
Persistent hypercapneic hypoxia
How is PPH mediated?
NO
What is an antitussive?
Drug that decreases cough
What are antitussive drugs?
Opioids
What is the primary antitussive drug we use?
Hydrocodone
Codeine
What is the mechanism of action of antitussives?
Opioids depress cough center in medulla
What are the side effects of antitussive drugs?
Sedation
Constipation
Bradycardia
What class of respiratory drugs relax bronchiole smooth muscle?
Bronchodilators
What class of drugs are bronchodilators?
Beta - 2 agonists
What are 3 beta-2 agonists?
Terbutaline
Albuterol
Clenbuterol
What is a bronchodilator that is not a beta-2 agonist
epinephrine
What is the mechanism of beta-2 agonists?
Smooth muscle in bronchioles are relaxed by innervation of the beta-2 nerves
What are bronchodilators used to treat?
Asthma
What of the beta 2 agonists are prohibited in food animals?
Clenbuterol
What are 2 side effects of beta 2 agonists?
Tachycardia
Muscle tremors
What are methylxanthines used for?
BronchodilatorsWh
What are 3 methylxanthines?
Caffeine
Theobromine
Theophylline
What is the mechanism of action of methylxanthines?
CNS stimulant
What are side effects of methylxanthines?
GI signs
Cardiac stimulation
Seizures
How often are methylxanthines used?
Not as often due to side effects
What species are methylxanthines more often used on?
Horses
What drug class is used to treat airway inflammation?
GlucocorticoidsW
What are 2/3 glucocorticoids?
Prednisone/prednisolone
Fluticasone
What is the mechanism of action of glucocorticoids?
Bind to receptors on cells and inhibit transcription of genes that produce mediators of inflammation
Many side effects with glucocorticoids, try to keep dosage low
What are glucocorticoids used to treat?
Bronchitis
Asthma
Recurrent airway obstruction
What is definition of hypoxemia?
SpO2<90%
PaO2<60
What is the single most important therapy for hypoxemia?
Oxygen
What are the 2 ways oxygen can exist?
Carried on hemoglobin
Dissolved in blood
What type of hypoxemia is from pneumonia?
V/Q mismatch
What are the 4 major causes of bacterial pneumonia?
Community acquired
Aspiration pneumonia
Foreign body
Immune dysfunction
What are some side effect of oxygen?
Tunnel vision, tinnitus, seizures
What is type 2 oxygen toxicity?
Penumocytes proliferate
What is type 1 oxygen toxicity?
Pneumocyte degenerate
What is a respiratory stimulant?
Doxapram
What is the mechanism of action of doxapram?
Inhibits potassium channels on carotid body cells (chemoreceptors) resulting in increased sensitivity to CO2
***What are the 5 causes of hypoxemia?
Reduced Fi02
Hypoventilation
V/Q mismatch
Right to left shunt
Diffusion impairment
When is doxapram used?
Neonatal resuscitation (not first line)
Reversal of anesthetic-induced patients
Which lung lobe is most likely to harbor aspiration pneumonia?
Right middle
How can you diagnose pneumonia in dogs and cats?
Tracheal wash
Should you culture/do cytology of nasal discharge?
NO
What 2 antibiotic options are available for bacterial pneumonia in dogs and cats?
Amoxicillin and doxycycline
What to do if moderate+ signs with pneumonia?
Dual therapy. For Gram + and -
In a critical patient, what should consider in terms of antibiotics?
Parental administration
When shouldn’t you consider providing antibiotics within 10 day duration for feline acute upper respiratory tract infection
No symptoms but has serous or mucopurulent discharge
How long do you treat the pneumonia past resolution of sings?
5-7 days
When should you consider providing antibiotics within 10 day duration for feline acute upper respiratory tract infection
Symptomatic WITH mucopurulent discharge
If there is no improvement in 7-10 days, what should your next steps be?
Additional diagnostics or different antimicrobial therapy
What is something to keep in mind when doing hydration of a pulmonary patient.
Really dont want to over hydrate
What is a large side effect of doxycycline in cats?
Esophageal stricture
