Vascular Flashcards
vascular tone is a critical determinant of
peripheral resistance
drugs that act on peripheral vasculature
inodilators
calcium channel blockers
adrenergic drugs
nitric oxide producers
are vasodilators beneficial for heart failure?
beneficial fro many types of heart failure (venous congestion, regurgitating blood flow, decreased tissue perfusion)
BUT NOT ALL PATIENTS WILL BENEFIT
Arterial vasodilation will
decrease resistance against which ventricle must pump (afterload)
venous vasodilation reduce filling pressures of right and left ventricles and decreases
preload
vascular smooth muscle contraction is different than cardiac muscle contraction and can be triggered by
passive stretching, electrical stimulation, chemical stimulation (receptor binding triggering Ca release from SR)
main players in control of vascular tone
adrenergic receptors (systemic), angiotensin II (systemic), bradykinin (local), prostaglandins (local), and nitric oxide (local)
all calcium channel blockers have some
vasodilatory effects
calcium channel blockers act by
blocking calcium influx into vascular smooth muscle cells
which calcium channel blocker has the most potent vasodilator effects
amlodipine and has less direct effects on the heart
amlodipine used to treat
systemic hypertension, not arrhythmias
- first choice for hypertension in cats with chronic renal failure
-treatment for mitral regurgitation in dogs (decreases after load)
goal of hypertension treatment is
gradual decrease in blood pressure with a minimal goal of achieving a systolic blood pressure of less than 160mm Hg
what adrenergic receptors are main regulators of systemic blood vessel tone
alpha 1 agonists
alpha 1 antagonists do what
dilate arteries and veins
some drugs may have a1 antagonism as an additional or adverse effect. examples
acepromazine, quinidine, carvedilol
drugs with indirect cardiovascular effects
diuretics
ACE inhibitors
Angiotensin II receptor blockers
Angiotensin Converting Enzyme (ACE) inhibitors examples
enalapril, benazepril, imidapril
ACE inhibitors do what
vasodilation (decrease TPR and after load)
diuretic effect through a decrease in aldosterone
decrease sympathetic input to heart
ACE inhibitors adverse effects
hypotension, decreased aldosterone
ACE inhibitors have a delayed onset of action due to partly
they’re pro drugs that require conversion to active metabolites - takes 1-2 weeks to see magnitude of response. therefore, NOT FOR ACUTE THERAPY but management
do ACE inhibitors increase lifespan ?
yes
do Angiotensin II receptor blockers have similar effects to ACE inhibitors?
yes
telmisartan - what is it
angiotensin II receptor blocker
telmisartan effects
treatment of hypertension and proteinuria associated with CKD
effective for blood pressure reduction
adverse effects of telmisartan?
GI effects, hypotension, anemia
-FETOTOXIC!!!!!
diuretics goal
reduce blood volume and mobilize edema
- furosemide diuretic of choice for cardiovascular dz
