Week 4: Cardiovascular-Renal Drugs: Vasodilators and the Treatment of Angina Pectoris Flashcards
the most common cause of angina is what?
atheromatous obstruction of the large coronary vessels (CAD)
inadequate blood flow in the presence of CAD results in ________ angina, also known as classic angina
effort angina
the diagnosis of angina is usually made on the basis of what two things?
history and stress testing
transient spasms of localized portions of these vessels, usually associated with underlying atheromas, can also cause significant myocardial ischemia and pain.
vasospastic or variant angia
vasospastic angina is also called what?
prinzmetal angina
the primary cause of angina pectoris is what?
an imbalance between the oxygen requirement of the heart and the oxygen supplied to it via the coronary vessels.
in ______ angina, the oxygen imbalance occurs when the myocardial oxygen requirement increases, especially during exercise
effort angina
with angina, the resulting ischemia with an accumulation of _____ ____ usually leads to pain
acidic metabolites
an acute coronary syndrome, is said to be present when episodes of angina occur at rest AND there is an increase in the severity, frequency and duration of chest pain in patients with previously stable angina
unstable angina
unstable angina is caused by episodes of increased epicardial coronary artery resistance or _______ occurring in the vicinity of an atherosclerotic plaque
small platelet clots
unstable angina is considered a medical emergency due to the high risk of what?
myocardial infarction and death
in effort angina, o2 demand can be reduced by decreasing cardiac work or by shifting myocardial metabolism to substrates that require less oxygen per unit of what?
adenosine triphosphate (ATP) produced
in variant angina, spasms of coronary vessels can be reversed by ____ or _______.
nitrates or CCB vasodilators
in unstable angina, vigorous measures are taken to achieve BOTH an increase in o2 delivery by medical or physical interventions and a decrease in _______ demand
oxygen
the three-drug groups traditionally used in angina
organic nitrates
CCBs
B-Blockers
because of their slow onset of action, CCBs and B-blockers are used for angina ________.
prophylaxis
Nitroglycerin is denitrated by mALDH in smooth muscle and other cells. This results in the release of nitrite ion, which is then converted to nitric oxide. Nitric oxide that is released stimulates guanylyl cyclase in smooth muscle, producing an increase in ______ which causes vasodilation.
cGMP
The major acute toxicities of organic nitrates are direct extensions of therapeutic vasodilation:
orthostatic hypotension, tachycardia, and a throbbing headache.
Nitrates are contraindicated if the _______ is elevated.
intracranial pressure
With continuous exposure to nitrates, the isolated smooth muscle may develop complete tolerance (__________), and the intact human becomes progressively more tolerant when long-acting preparations (oral, transdermal) or continuous intravenous infusions are used for more than a few hours without interruption.
tachyphylaxis
with nitrates, supplementation of______ may partially reverse tolerance, suggesting that reduced availability of sulfhydryl donors may play a role.
cysteine
potential deleterious effects of nitrate-induced vasodilation
reflex tachycardia
reflex increase in contractility
Calcium channel-blocking agents also relieve and prevent focal coronary artery spasms in ______ angina
variant angina
CCB can be used as prophylactic treatment for what kind of angina
variant angina