Cardiovascular Flashcards
What is angina?
a supply/demand problem (suppl of blood to myocardium is not sufficient to meet the demands)
What is perfusion?
blood flow
What are the consequences of angina?
decreased myocardial perfusion so decreased metabolite removal and decreased oxygenation
Which drug is often administered for acute angina attacks?
Nitroglycerin (usually sublingual for fast acting effect)
What are the methods of administration of nitroglycerin?
Sublingual tablets and spray (acute)
transdermal patches and ointment (chronic/prophylactic)
Nitroglycerin mechanism of action?
pro drug: enters smooth muscle and converted to nitric oxide
can limit platelet adhesion and aggregation
dilates vessels intrinsically (heart) and extrinsically (peripheral vessels)
Describe the timeframe of nitroglycerin action.
2 minutes: starts to work
4 minutes: PEAK
10 minutes: max effect
30-60 minutes: duration
Nitroglycerin side effects?
flushing, headache, dizziness, reflex tachy
What should be done to reduce side effects of nitroglycerin?
Pt should be seated to reduce pooling of blood to the legs which causes side effects.
When seated, the venous dilatation in the legs causes a decrease in blood pressure.
What is the max dose of nitroglycerin for an acute attack?
3 tabs (distributed one at a time at 5 minute intervals)
What if 3 nitroglycerin tabs don’t work?
Patient is probably having an MI (or the tabs have expired/deteriorated)
What is mechanism of action of beta adrenergic blockers?
decrease myocardial oxygen consumption by reducing myocardial contractility, HR, and BP
Why avoid sudden withdrawal of beta adrenergic blockers (especially with angina or post-MI therapy)?
risk for acute MI and sudden death
What is mechanism of action of Ca Channel blockers?
dilate systemic arteries and main coronary arteries; heart pumps against less resistance; decreases myocardial oxygen consumption
Ca Channel blockers (especially verapamil) may cause what changes?
decreased heart rate and myocardial contractility
Causes of CHF?
ischemic heart disease, HTN, cardiomyopathy, vavular and pericardial disease
CHF non-pharmacological interventions?
stop smoking, control HTN, dec sodium, moderate exercise, dec stress
CHF pharmacological management is “mix and match” including:
ace inhibitors (usually first line of therapy) thiazide loop diuretics, a-adrenergic blockers (B-Blockers), digoxin, hydralazine/isosorbine also used
ACE inhibitors have names usually ending in -____.
-pril.
What is mechanism of action of ACE inhibitors?
indirectly dec. aldosterone secretion
inhibits vascular smooth muscle contraction
VASODILATION
dec. peripheral resistance
Side effects of ACE inhibitors?
cough, decreased/loss of taste perception, hypotension, potassium retention
Angiotensin II Receptor Antagonists mechanism of action?
VASODILATION
increased sodium and water excretion
Diuretic Classes (3)
thiazides
loop diuretics (lasix)
potassium-sparing diuretics
Effect of diuretics?
control excessive fluid and edema, dec. workload on the heart
Diuretics and CHF?
Used in combination for CHF: inc. effects and safety of ACEIs and Beta Blockers (but diuretics should not be used alone for CHF)
Digoxin (Lanoxin) mechanism of action?
positive inotropic effect (increase strength of muscular contractions)
Digoxin (Lanoxin) side effects?
side effects/adverse effects with toxicity can be FATAL: cardiac arrhythmia, CNS (mental status change, disorientation, blurred vision)
What patients is Digoxin (Lanoxin) best for?
pts with abnormal contractility (often atrial flutter/fibrillation) or rapid ventricular rate
What is usual dose of Digoxin (Lanoxin)?
0.125 mg
remember, toxicity is a huge problem ~25% of patients experience signs of toxicity
Digoxin (Lanoxin) drug interactions?
diuretics - due to hypokalemia - directly increases risk of toxicity
Vasodilator that has direct effect on smooth muscles of arterioles but no effect on veins:
Hydralazine (often used in combination with a diuretic and/or B-Blocker)
What is the effect of B-blockers to notice with exercise?
muted cardiovascular response
