Cardiovascular Flashcards
Name three positive inotrope medications
Pimobendan, dopamine, dobutamine
What is the purpose of positive inotrope medications?
Increase cardiac contractility
What’s the mechanism of action of dopamine and how does that affect the patient?
Acts on beta-1 receptors to stimulate norepinephrine release. This causes increased cardiac contractility, arterial constriction, and increased blood pressure.
Which drug, dopamine or dobutamine, should be avoided in patients with severe cardiac disease and why?
Dopamine as it will cause an increase in cardiac afterload.
How can loop diuretics activate RAAS?
They cause a decrease in renal blood flow which triggers the release of renin, which begins the RAAS cascade.
Name three diuretics
Furosemide, spironolactone, torsemide.
Which diuretic spares potassium and avoids activating RAAS?
Spironolactone
What is the suffix of all ACE inhibitors?
Pril
What is the mechanism of action of an ACE inhibitor?
It essentially prevents RAAS by inhibiting angiotensin converting enzyme (ACE) which prevents the conversion of angiotensin 1 to angiotensin 2.
Name the two most common ACE inhibitors in vet med?
Enalapril, benazepril.
Where are beta-1 receptors located?
In the heart
Define cardiac preload
The volume of fluid in the heart prior to contraction.
Define cardiac afterload
The ventricular pressure at the end of cardiac contraction. Essentially, the pressure the heart has to push against to contract.
Where are alpha receptors located?
Arteries
What hormones stimulate alpha receptors to constrict arteries and increase blood pressure and venous return?
Epinephrine and norepinephrine