Vasodilators and Angina Flashcards
Test 2
What is vascular tone?
Smooth muscle being in a continuously partially contracted state
What is the primary vascular tone?
Arterial
What are the 2 functions of our venous system?
- Conduct blood back to the heart
- Reservoir for blood volume
How much blood does our venous system hold?
70% of blood volume
20-30% in splanchnic bed
What is angina pectoris?
Chest pain d/t accumulation of metabolites from myocardia ischemia
What provides immediate relief from angina?
Nitroglycerin
What are prophylaxis for angina?
CCB
Beta blockers
Describe classic/stable angina
O2 deficit bc require increases
Cause: Plaque
Ex) exercise
Needs more O2
Describe Variant Angina
Coronary vasospasm
“Prinzmetal angina”
Hard to treat
Tx: Nitrates, CCB
Describe Unstable Angina
“Angina at rest”
Cause: Small clots in vicinity
Emergency
Tx: Nitroglycerin
Describe Coronary Blood Flow
No flow during systole
Perfused during diastole
Drugs: Nitroglycerin
Nitrate
NO release in vascular smooth muscle
- Activates guanylyl cyclaces
- Guanylyl cyclase activates GTP to produce cGMP
- Removes phosphate from MLCK
- Relaxation of vascular smooth muscle
sublingual
Low oral bioavailability
E: Kidneys
What is Amyl Nitrite?
Inhaled Nitrite
Concerns with overexposure to nitrates and nitrites
Hemoglobin interactions (methemoglobin)
Reflex tachycardia
Orthostatic hypotension, syncope, HA
Tolerance
What does overexposure to Nitrates/nitrites do to blood?
Makes Hgb less likely to bind to O2 d/t formation of methemoglobin
List receptor differences in epicardial arteries.
At the beginning where it is entering the heart: - Alpha-1 and Beta-1 receptors
Micro-arteries:
- Beta-2 and alpha-2 (SNS binding leads to dilation)
Contrast the therapeutic and adverse effects of nitrates, β blockers, and calcium channel blockers when used for angina
BB - Decrease oxygen demand by decreasig CO
CCB - Smooth muscle relaxation –> Decrease contractility, SA node rate, AV conductance
What is a pFox inhibitor?
Fatty acid oxidation inhibitor
How do pFox inhibitors work?
Inhibiting FOX
Decrease O2 requirement in cardiac metabolism
Increases glucose utilization
What drugs are contraindicated for angina?
Hydralazine
Minoxidil
Nitroprusside
Fenoldepam
