Cardiovascular

Question 1

Name three positive inotrope medications

Answer 1

Pimobendan, dopamine, dobutamine

Question 2

What is the purpose of positive inotrope medications?

Answer 2

Increase cardiac contractility

Question 3

What’s the mechanism of action of dopamine and how does that affect the patient?

Answer 3

Acts on beta-1 receptors to stimulate norepinephrine release. This causes increased cardiac contractility, increased heart rate, arterial constriction, and increased blood pressure.

Question 4

Which drug, dopamine or dobutamine, should be avoided in patients with severe cardiac disease and why?

Answer 4

Dopamine as it will cause an increase in cardiac afterload.

Question 5

How can loop diuretics activate RAAS?

Answer 5

They cause a decrease in renal blood flow which triggers the release of renin, which begins the RAAS cascade.

Question 6

Name three diuretics

Answer 6

Furosemide, spironolactone, torsemide.

Question 7

Which diuretic spares potassium and avoids activating RAAS?

Answer 7

Spironolactone

Question 8

What is the suffix of all ACE inhibitors?

Answer 8

Pril

Question 9

What is the mechanism of action of an ACE inhibitor?

Answer 9

It essentially prevents RAAS by inhibiting angiotensin converting enzyme (ACE) which prevents the conversion of angiotensin 1 to angiotensin 2.

Question 10

Name the two most common ACE inhibitors in vet med?

Answer 10

Enalapril, benazepril.

Question 11

Where are beta-1 receptors located?

Answer 11

In the heart

Question 12

Define cardiac preload

Answer 12

The volume of fluid in the heart prior to contraction.

Question 13

Define cardiac afterload

Answer 13

The ventricular pressure at the end of cardiac contraction. Essentially, the pressure the heart has to push against to contract.

Question 14

Where are alpha receptors located?

Answer 14

Arteries

Question 15

What hormones stimulate alpha receptors to constrict arteries and increase blood pressure and venous return?

Answer 15

Epinephrine and norepinephrine

Question 16

Where are beta-2 receptors located?

Answer 16

Lungs and skeletal tissue

Question 17

When stimulated, what do beta-1 receptors do?

Answer 17

Increase heart rate and cardiac contractility.

Question 18

When stimulated, what do beta-2 receptors do?

Answer 18

Cause bronchodilation and vasodilation in skeletal muscle.

Question 19

How can pimobendan assist in cardiogenic shock?

Answer 19

It balances vasodilation and increases cardiac contractility.

Question 20

How do positive inotropes increase cardiac contractility?

Answer 20

They increase available calcium for protein binding or they increase protein sensitivity to calcium.

Question 21

What is the mechanism of action for dobutamine?

Answer 21

It acts on beta-1 receptors to increase cardiac contractility and cardiac output.

Question 22

Where is angiotensin converting enzyme (ACE) produced?

Answer 22

The lungs.

Question 23

Which cardiac medication is a calcium channel blocker that acts primarily as an arterial vasodilator?

Answer 23

Amlodipine.

Question 24

What is diltiazem used for and what is its primary mechanism of action?

Answer 24

It is used to treat supraventricular tachycardia (SVT) and it is a calcium channel blocker.

Question 25

Which drug is most useful in the management of atrial fibrillation to slow AV nodal conduction?

Answer 25

Digoxin

Question 26

Which cardiac medication is derived from the poisonous foxglove plant?

Answer 26

Digoxin

Question 27

Which two cardiac drugs, when combined, have a marked affect at reducing the ventricular response rate of atrial fibrillation?

Answer 27

Digoxin and diltiazem

Question 28

What is lidocaine’s mechanism of action and what does it treat?

Answer 28

Lidocaine is a sodium channel blocker that is used to manage ventricular arrhythmias in dogs.

Question 29

What is sotalol’s mechanism of action and what does it treat?

Answer 29

Sotalol is a nonselective beta-adrenergic blocker and a potassium channel blocker. It’s primary use is to treat ventricular tachyarrhythmias.

Question 30

Name the three most common beta blockers.

Answer 30

Propranolol, atenolol, and sotalol.

Question 31

What is the specific mechanism of action of beta blockers?

Answer 31

They block beta one and beta two receptors which promotes a steady heart rate and slightly reduces cardiac contractility.

Question 32

Which medication has a variety of mechanism of actions and can work as a beta blocker, a sodium channel blocker, and a calcium channel blocker?

Answer 32

Amiodarone

Question 33

In what instances would amiodarone be used?

Answer 33

It is useful for both ventricular and atrial arrhythmias and can be useful when traditional anti-arrhythmic drug therapies do not work.

Question 34

What is the most powerful vasodilator in veterinary practice?

Answer 34

Nitroprusside.

Question 35

What is nitroprusside’s primary use?

Answer 35

It reduces preload and afterload assisting in treatment of severe hypertension and CHF.

Question 36

In what location of the body would nitroglycerin be applied in an acute situation and why?

Answer 36

It should be applied to a hairless area of the abdomen, because perfusion to the ears may not be sufficient for drug uptake.

Question 37

Which medication is commonly used for feline urinary obstruction but can also be used as an alpha receptor blocker to decrease blood pressure?

Answer 37

Prazosin.

Question 38

Which rhythms during CPA are considered shockable?

Answer 38

Ventricular fibrillation and pulseless ventricular tachycardia.

Question 39

Which ECG rhythms are not shockable during CPA?

Answer 39

Pulseless electrical activity and asystole.

Question 40

If the first defibrillation is not successful, should you adjust the joules on the defibrillator?

Answer 40

Yes, you should double the joules for the next attempt.

Question 41

If a canine patient has refractory shockable rhythms, what are drugs to consider administering?

Answer 41

Lidocaine and esmolol.

Question 42

If a patient has had 15 minutes of unsuccessful CPR, is it reasonable to administer sodium bicarbonate? What if you don’t have an acid base status?

Answer 42

Yes. Even without an acid base status, the patient is most likely acidotic due to persistent unsuccessful CPR.

Question 43

How many times is it acceptable to repeat atropine if the initial dose did not benefit CPR? Why?

Answer 43

Atropine should not be repeated. It has a long half-life and will accumulate when repeated.

Question 44

What is the difference on ECG between pulseless VT and PEA?

Answer 44

The heart rate will be above 200bpm if it’s VT. PEA usually has a low heart rate.

Question 45

What is the difference on ECG between pulseless VT and VF?

Answer 45

VT will have consistent complexes that are the same size, VF will have chaotic complexes varying in size.

Question 46

What medication would be beneficial to cats, but not dogs when multiple defibrillations have failed to initiate ROSC on a shockable rhythm?

Answer 46

Amiodorone.

Question 47

How often is it acceptable to repeat epinephrine during CPR?

Answer 47

Every 4 minutes or every other rotation of CPR.

Question 48

Why would you immediately initiate compressions again after defibrillating instead of pausing and examining the ECG?

Answer 48

It will take at least 2 minutes of compressions to get consistent contractions of the heart to return after defib.

Question 49

In what situation would vasopressin be more beneficial than epinephrine at causing peripheral vasoconstriction?

Answer 49

Vasopressin’s efficacy is not dependent on pH like epi, so if the patient is severely acidotic, vasopressin will be more effective.

Question 50

When should open chest CPR be initiated if a feline or small canine patient is not responding to closed chest CPR? Why?

Answer 50

Open chest CPR is not recommended in cats or small dogs. Due to their size, you have almost equal chances of attaining ROSC with closed chest CPR.

Question 51

In regards to hyperkalemia, how does an infusion of calcium gluconate assist in treatment and does it treat the hyperkalemia?

Answer 51

It stabilizes the resting potential of the heart, but does not treat the hyperkalemia.