21 Drugs For Angina Pectoris, Myocardial Infarction, And Cerebrovascular Accident

Directory Classroom Response System Lecture Note Presentation

Question 1 The patient should remove the transdermal nitroglycerin patch at night to:

Question 1 Choices Prevent overdose Prevent adverse reactions Ensure the dosage is appropriate Delay development of tolerance

Question 1 Answer Prevent overdose Prevent adverse reactions Ensure the dosage is appropriate Delay development of tolerance

Question 2 When treating angina, the nurse knows that the mechanism of action of a beta-adrenergic blocker is:

Question 2 Choices Slowed heart rate and decreased contractility of the heart Relaxation of arterial and venous smooth muscle Increased contractility and heart rate Decreased peripheral resistance

Question 2 Answer Slowed heart rate and decreased contractility of the heart Relaxation of arterial and venous smooth muscle Increased contractility and heart rate Decreased peripheral resistance

Question 3 The patient taking calcium channel blockers should use extreme caution when taking which of the following medications?

Question 3 Choices Acetaminophen (Tylenol) Ibuprofen (Motrin) Digoxin (Lanoxin) Ranitidine (Zantac)

Question 3 Answer Acetaminophen (Tylenol) Ibuprofen (Motrin) Digoxin (Lanoxin) Ranitidine (Zantac)

Question 4 The patient is complaining of a viselike pain in his chest that subsides with rest. The patient is likely experiencing:

Question 4 Choices A stroke A myocardial infarction Angina A cerebral vascular accident

Question 4 Answer A stroke A myocardial infarction Angina A cerebral vascular accident

Learning Outcomes Describe how the myocardium receives its oxygen and nutrient supply. Explain the pathophysiology of angina pectoris. Identify lifestyle changes that may be implemented to manage symptoms of angina.

Learning Outcomes Explain the pathophysiology of myocardial infarction. Describe the pharmacologic treatment of CVA.

Learning Outcomes For each of drug classes listed in the Drug Snapshot, identify representative drugs, explain the mechanisms of drug action, primary actions, and important adverse effects as they relate to the treatment of angina, myocardial infarction or CVA.

Learning Outcomes Categorize drugs used to treat angina, myocardial infarction, and CVA based on their classification and mechanisms of action.

Core Concept 21.1 Coronary heart disease is caused by a restriction in blood flow to the myocardium.

Heart Facts Heart is the hardest working organ in the body Heart muscle or myocardium must receive a continuous supply of oxygen and nutrients

Heart Facts Receives essentially no nutrients from the blood traveling through the heart’s chambers Heart muscle receives its nutrients from the first two arteries branching off the aorta, the right and left Coronary Arteries

Core Concept 21.2 Angina pectoris is characterized by severe chest pain caused by lack of sufficient oxygen flow to heart muscle.

Angina Pectoris Most common cause is atherosclerosis A buildup of fatty, fibrous material called plaque in the walls of arteries Reduced blood supply to cardiac muscle cells is called myocardial ischemia

Angina Pectoris Classic presentation Intense pain in the chest Often moving to the left side of the neck and lower jaw and down the left arm

Figure 21.1 Plaque and thrombus formation in the coronary artery Source: Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ

Types of Angina Stable Angina Predictable in its frequency, intensity, and duration

Types of Angina Unstable Angina More frequent or severe, occurs during periods of rest Requires more aggressive medical intervention. Sometimes considered a medical emergency because it is associated with an increased risk of MI.

Types of Angina Vasospastic or Prinzmetal’s angina Caused by spasms of the coronary arteries Pain occurs most often during periods of rest

Core Concept 21.3 Anginal pain can often be controlled through positive lifestyle changes and surgical procedures.

Life Style Changes Limit alcohol consumption to small amounts. Eliminate foods high in cholesterol or saturated fats. Keep blood cholesterol and other lipid indicators within the normal ranges. Do not use tobacco.

Life Style Changes Keep blood pressure within the normal range. Exercise regularly and maintain optimum weight. Keep blood glucose levels within normal range. Limit salt (sodium) intake. Reduce stress levels as much as possible.

Surgical Intervention Coronary arteries are significantly obstructed Percutaneous transluminal coronary angioplasty (PTCA), with stent insertion Coronary artery bypass graft (CABG)

Concept Review 21.1 How can a health care provider distinguish between stable angina and unstable angina?

Core Concept 21.4 The pharmacological management of angina is achieved by reducing cardiac workload.

Pharmacologic Treatment Goals Reduce the frequency of anginal episodes Terminate acute anginal pain in progress

Pharmacologic Treatment This can be accomplished by Slowing the heart rat Dilating veins so the heart receives less blood (reduced preload) Causing the heart to contract with less force (reduced contractility) Lowering blood pressure, thus offering the heart less resistance when ejecting blood from the ventricles (reduced afterload)

Three Classes of Drugs Organic nitrates drugs of choice for terminating acute angina pain Beta-adrenergic blockers drugs of choice for preventing angina pain Calcium channel blockers are used when beta blockers are not tolerated well

Figure 21.2 Mechanisms of action of drugs used to treat angina pectoris

Core Concept 21.5 The organic nitrates relieve anginal pain by dilating veins and the coronary arteries.

Two Types of Nitrates Short acting Long acting Example: Nitroglycerin Taken sublingually Quickly stop an acute anginal attack in progress Long acting Example: isosorbide dinitrate

Two Types of Nitrates Taken orally or delivered through a transdermal patch Decrease the frequency and severity of anginal episodes. Side Effects: orthostatic hypotension,reflex tachycardia, headache,flushing of the skin

Table 21.2 (continued) Selected Drugs for Angina and Myocardial Infarction

Table 21.2 (continued) Selected Drugs for Angina and Myocardial Infarction

Core Concept 21.6 Beta-adrenergic blockers are often drugs of choice for reducing the frequency of angina attacks.

Beta-adrenergic Blockers Reduce the workload on the heart used for angina prophylaxis Side Effects:fatigue, lethargy and depression occur Slow the heart rate, contraindicated in patients with bradycardia and heart block

Beta-adrenergic Blockers Heart rate should be closely monitored so that it does not fall below 50-60 beats/min at rest or 100 beats/min during exercise.

Core Concept 21.7 Calcium channel blockers relieve anginal pain by reducing the cardiac workload.

Calcium Channel Blockers Decreases the myocardial oxygen demand Reduce myocardial oxygen demand by lowering blood pressure and slowing the heart rate Cause arteriolar smooth muscle to relax

Calcium Channel Blockers Lower peripheral resistance and reducing blood pressure Dilate the coronary arteries, bringing more oxygen to the myocardium Drug of choice for vasospastic angina

Concept Review 21.2 How does decreasing the workload on the heart result in reduction in anginal pain?

Core Concept 21.8 The early diagnosis and treatment of myocardial infarction increases chances of survival.

Figure 21.3 Blockade and reperfusion following myocardial infarction (MI): (a) blockage of left coronary artery causing myocardial ischemia; (b) infusion of thrombolytics; (c) blood supply returning to myocardium; (d) thrombus dissolving and ischemia clearing Source: (a) and (c) Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ

Figure 21.3 (continued) Blockade and reperfusion following myocardial infarction (MI): (a) blockage of left coronary artery causing myocardial ischemia; (b) infusion of thrombolytics; (c) blood supply returning to myocardium; (d) thrombus dissolving and ischemia clearing Source: (a) and (c) Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ

Figure 21.3 (continued) Blockade and reperfusion following myocardial infarction (MI): (a) blockage of left coronary artery causing myocardial ischemia; (b) infusion of thrombolytics; (c) blood supply returning to myocardium; (d) thrombus dissolving and ischemia clearing Source: (a) and (c) Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ

Figure 21.3 (continued) Blockade and reperfusion following myocardial infarction (MI): (a) blockage of left coronary artery causing myocardial ischemia; (b) infusion of thrombolytics; (c) blood supply returning to myocardium; (d) thrombus dissolving and ischemia clearing Source: (a) and (c) Reprinted by permission of Pearson Education, Inc., Upper Saddle River, NJ

Goals of the Pharmacologic Treatment of MI Restore blood supply (perfusion) to the damaged myocardium as quickly as possible through the use of thrombolytics Reduce myocardial oxygen demand with organic nitrates, beta blockers or CCBs to prevent another MI

Goals of the Pharmacologic Treatment of MI Control or prevent MI-associated dysrhythmias with beta blockers or other antidysrhythmics Reduce post-MI mortality with aspirin, beta blockers and ACE inhibitors Manage severe chest pain and associated anxiety with analgesics

Thrombolytics dissolve clots blocking the coronary arteries. Core Concept 21.9 Thrombolytics dissolve clots blocking the coronary arteries.

The Goals Thrombolytic Therapy Dissolve clots that are obstructing the coronary arteries Restore circulation to the myocardium Thrombolytics are most effective when administered from 20 minutes to 12 hours after the onset of MI symptoms

Core Concept 21.10 Drugs are used to treat the symptoms and complications of acute myocardial infarction (MI).

Treatment of MI Immediate Need Ensure that the heart continues functioning Permanent damage from the infarction is minimized

Treatment of MI Drugs Used Beta-adrenergic blockers Antiplatelets and anticoagulants Angiotensin-converting Enzyme (ACE) inhibitors Pain management

Concept Review 21.3 Why is it important to treat an MI within the first 24 hours after symptoms have begun? What classes of drugs are used for this purpose?

Aggressive treatment of CVA can increase survival Core Concept 21.11 Aggressive treatment of CVA can increase survival

Treatment of CVA Two main goals Prevention of strokes through the use of anticoagulants and antihypertensive agents Restoration of blood supply to the affected portion of the brain as quickly as possible. Thrombolytics as soon as the patient arrives at the hospital These agents are most effective if administered within 3 hours of the attack.