depresses SA node - decrease hr and impulses from SA to AV node
important thing to remember in giving adenosine?
give rapidly in closest port - follow by saline bolus
3 classes of anti-angina drugs?
- nitrates (acute)
- beta blockers (long term prevention)
- calcium channel blockers (when other drugs fail)
How do nitrates work?
vasodilation - decreases blood return to heart (preload) which decreases O2 demand on heart because it doesn't have to pump as hard
- decreases afterload by dilating the arteries
Classes of anti-hypertensives
calcium channel blockers
ACE inhibitors (angiotensin converting enzyme inhibitors) - how do they work?
interrupt renin-angiotensin system.
Prevents angiotensin I from being converted to angiotensin II which is a vasoconstrictor and which promotes aldosterone(sodium/water retention) thus vaso dilation and fluid excretion - decreases preload
ACE inhibitors - used for what?
- left heart failure
- post MI
ACE inhibitors - common ones
ARBs (angiotensin II receptor blocking agents) how do they work?
block the vasoconstriction effect of angiotensin II
ARB's - common ones
ARBs - used for
Clonidine - used for what - how does it work
used for hypertension
- inhibits SNS - causing vasodilation and decresed CO