2. What is Acute Coronary Syndrome (ACS)?
• Indicates an interruption of blood flow to the heart
Unstable angina
Non-ST elevation MI
ST elevation MI
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3. What Causes ACS To Develop?
• An imbalance between supply and demand of O2
• Atherosclerotic plaque rupture in coronary artery
• Thrombosis (clot) formation in artery
• Coronary spasm
• Dissection of blood vessel
• Increased demand of O2 in face of fixed obstruction
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4. Main Contributing Risk Factors to Cardiac
Problems
• Hypertension
• Hyperlipidemia
• Smoking
• Diabetes
• Notice: all of the above are considered modifiable
risk factors – you can do something to control
them!
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5. Pathophysiology of angina
• Chest pain/discomfort related to a decrease in oxygen-rich
blood flow
• Usually due to coronary artery disease (CAD)
• Atherosclerosis
• Build up of plaque over time that narrows the internal diameter
of the vessel
• Arteriosclerosis
• Stiffening of vessels over a period of time which makes them less
pliable
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7. Stable Angina
• Most common form
• Pain occurs when oxygen demand is greater than the
supply during periods of increased workload of the heart
• Can usually predict activities that will trigger an event
• Usually treated with rest and medication (i.e.:
nitroglycerin)
• This is a warning that the patient may have an acute MI
in the future
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8. Unstable Angina
• Pain that is unpredictable and can occur at rest
• May not stop with rest and/or medication
• Event to be taken seriously
• May be predicting an imminent acute MI in the
near future
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9. Variant Angina
• Occurs when vessel is in spasm
• Very painful
• Often occurs at night
• Controlled with medication
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10. DRUGS USED IN THE TREATMENT OF
ANGINA PECTORIS
DRUGS USED IN ANGINA PECTORIS
Vasodilators Cardiac depressants
Nitrates Calcium blockers Beta-blockers
11. Nitrates
• These agents are simple nitric and nitrous acid esters of polyalcohol's.
Nitroglycerin may be considered the prototype of the group
• Pharmacokinetics
• The liver contains a reductase enzyme that removes nitrate groups and
ultimately inactivates the drug. Therefore, oral bioavailability low (typically
<10–20%). sublingual route, which avoids the first-pass effect, is preferred for
achieving a therapeutic blood level rapidly within a few minutes .
• When much longer duration of action is needed, oral preparations can be given
that contain an amount of drug sufficient to result in sustained systemic blood
levels of the parent drug plus active metabolites.
12. • Once absorbed, the unchanged nitrate compounds have half-lives of
only 2–8 minutes.
• The partially denitrated metabolites have much longer half-lives (up to
3 hours).
• For prompt relief of an angina attack precipitated by exercise or
emotional stress, sublingual (or spray form) nitroglycerin is the drug
of choice.
• All patients suffering from angina should have nitroglycerin on hand
to treat acute angina attacks
• Excretion, primarily, is largely by way of the kidney.
13. • For prompt relief of an angina attack precipitated by
exercise or emotional stress, sublingual (or spray
form) nitroglycerin is the drug of choice.
• All patients suffering from angina should have
nitroglycerin on hand to treat acute angina attacks
14. Mechanism
• After more than a century of study, the mechanism of action of nitroglycerin
is still not fully understood
• Nitrates relax vascular smooth muscle by intracellular conversion to nitrite
ions and then to nitric oxide, which activates guanylate cyclase and increases
the cells’ cyclic guanosine monophosphate (cGMP). Elevated cGMP
ultimately leads to dephosphorylation of the myosin light chain, resulting in
vascular smooth muscle relaxation
• Nitrates such as nitroglycerin cause dilation of the
• large veins, which reduces preload (venous return to the heart) and,
therefore, reduces the work of the heart.
18. Therapeutic Uses
• Stable Angina Pectoris
• Short-Acting Nitrates for Standby Therapy
• Longer-Acting Nitrates for the Prophylaxis of Angina
• Variant Angina
• Congestive Heart Failure.
• Unstable Angina Pectoris (Acute Coronary Syndromes)
19. Adverse effects
• Headache is the most common adverse effect.
• High doses of nitrates cause postural hypotension, facial flushing, and
tachycardia..
• Tolerance to the actions of nitrates develops rapidly as the blood vessels become
desensitized to vasodilation.
• It can be overcome by providing a daily “nitrate-free interval” to restore
sensitivity to them drug. This interval of 10 to 12 hours is usually taken at night
because demand on the heart is decreased at that time.
• Variant angina worsens early in the morning, perhaps due to circadian
catecholamine surges. Therefore, the nitrate-free interval in these patients should
occur in the late afternoon.
