chapter 45: calcium channel blockers Flashcards
what are three overall therapeutic uses of calcium channel blockers
hypertension, angina pectoris and cardiac dysrhythmias
what do calcium channel blockers have the greatest effect on
heart and vascular smooth muscle
what are calcium channels
gated pores in cytoplasmic membrane that regulate entry of calcium into cells
what do calcium channels regulate in the VSM
contraction
what do calcium channels act on in the VSM
peripheral arterioles and arterioles in the heart
action potential causes calcium channels to do what
calcium channels open and ions move inward which causes contraction
what do calcium channels do in the heart
helps regulate function of the myocardium, SA and AV
what are calcium channels coupled to
beta1 adrenergic receptors
what happens if calcium channels are blocked
relaxation
what do calcium channel blockers do to inotropic effect, force of contractility, heart rate and dromotopic effect?
all are decreased
what type of chronotropic effect does calcium have?
positive
what type of inotropic effect does calcium have?
positive
what type of dromotropic effect does calcium have?
positive
what CCB works on arterioles at therapeutic doses?
nefedipine
if nifedipine dose becomes toxic, what effects could it produce?
significant cardiac suppression
what could nifedipine help with
coronary perfusion