Download Notes on Angina and MI`s

Nursing 202 – Notes on Angina and MI’s
1. Myocardial ischemia develops when there is inadequate blood supply to meet the
metabolic demands of cardiac muscle.
The myocardium requires a continuous supply of oxygen to function properly. When
the supply of oxygen is insufficient in meeting the workload demands of the heart,
myocardial ischemia occurs. Narrowing of the lumen of the coronary arteries due to
atherosclerotic plaque reduces the oxygen supply to the myocardium.
2. Coronary artery disease is the major cause of myocardial ischemia.
Narrowing of the lumen on a coronary artery can result in angina. In angina,
atherosclerotic vessels are unable to respond to increases in cardiac workload. If plaque
completely occludes a coronary artery, an MI results.
3. Angina pectoris is characterized by severe chest pain brought on by physical exertion
or emotional stress.
Angina pectoris is the narrowing of a coronary artery, resulting in a lack of sufficient
oxygen to the heart muscle. Chest pain upon emotional stress or physical exertion is the
most characteristic symptom. Angina occurs in several forms: stable, vasospastic,
silent, or unstable. Anginal pain is similar to that experienced during an MI.
4. Therapeutic lifestyle changes can decrease the frequency of angina episodes and reduce
the risk of coronary artery disease.
Nonpharmacological means of angina management include limiting alcohol and
saturated fats in the diet, eliminating tobacco use, and keeping blood glucose, blood
lipids, and blood pressure within normal ranges.
5. The pharmacological management of angina includes beta-adrenergic blockers, organic
nitrates, and calcium channel blockers.
The pharmacological goals for the treatment of angina are to terminate acute attacks
and prevent future episodes. This is usually achieved by reducing cardiac workload.
Therapies include beta-adrenergic antagonists and calcium channel blockers for angina
prophylaxis. The most rapid and effective therapy for acute anginal pain is sublingual
nitroglycerin.
6. Organic nitrates may be used to terminate or prevent angina episodes.
The organic nitrates relieve angina by dilating veins and coronary arteries. The shortacting nitrates are drugs of choice for terminating acute angina pain. The long-acting
agents are used to reduce the frequency of angina episodes, however, tolerance can
limit their use.
7. Beta-adrenergic antagonists are often drugs of choice for stable angina.
Beta-adrenergic blockers relieve angina pain by decreasing the oxygen demands on the
heart: lowering blood pressure, slowing heart rate, and reducing contractility. They are
drugs of choice for preventing acute angina episodes.
8. Calcium channel blockers are effective at reducing myocardial oxygen demand and
treating stable and vasospastic angina.
Calcium channel blockers relieve angina by dilating the coronary vessels and reducing
the workload on the heart. They are drugs of choice for treating vasospastic angina, and
are effective alternatives for stable angina when beta blockers are contraindicated.
9. The early diagnosis and pharmacotherapy of myocardial infarction increases chances of
survival.
The early diagnosis of MI allows for more aggressive pharmacotherapy and decreases
patient mortality. Early pharmacotherapy may include thrombolytics, aspirin, betablockers, and antidysrhythmics.
10. Thrombolytic agents can restore perfusion to ischemic regions of the myocardium if
administered soon after an myocardial infarction.
Thrombolytic agents dissolve clots and restore perfusion to affected regions of the
myocardium. They must be administered less than 24 hours after the onset of
thromboembolic symptoms to be effective. Abnormal bleeding is a serious adverse
effect of this class of drugs.
11. Drugs are used to treat the symptoms and complications of acute myocardial infarction.
A number of additional drugs are used to treat the symptoms and complications of
acute MI. Most of these agents have been found through research to decrease post-MI
mortality. These include beta blockers, anticoagulants, antiplatelet agents,
antidysrhythmics, and ACE inhibitors.
12. Vasopressors are used following cardiopulmonary arrest to reestablish coronary and
cerebral blood flow.
Pharmacotherapy during cardiopulmonary resuscitation includes vasopressors such as
epinephrine, which raises cerebral, coronary, and systemic blood pressure. Amiodarone
is a drug of choice for preventing the recurrence of ventricular fibrillation or other
serious dysrhythmias that are serious complications following an MI.