Lehne Chapter 53: Management of ST-Elevation Myocardial Infarction

Results from tissue perfusion reduction (low cardiac output and blood flow).

What does cardiogenic shock result from?

To improve ventricular function, limit the size of the infarct, and reduce mortality.

What is the goals of fibrinolytic (thrombolytic) therapy?

The answer is D. In patients undergoing PCI, clopidogrel is used in combination with aspirin. Aspirin suppresses platelet aggregation, thereby reducing mortality by reducing the likelihood of reinfarction or stroke.

For all patients undergoing percutaneous coronary intervention (PCI), which drug is recommended to be combined with clopidogrel [Plavix]? A) Heparin B) ACE inhibitor C) Alteplase [Activase] D) Aspirin

The answer is D. Estrogen therapy for postmenopausal women is not effective as secondary prevention of another myocardial infarction and should not be initiated. In patients with acute MI, ACE inhibitors decrease severe heart failure. A post-MI patient should take a beta blocker, an ACE inhibitor, and an antiplatelet drug indefinitely. To prevent mortality after an MI, a diabetic patient's blood pressure should be less than 130/80 mm Hg.

A female patient who is diabetic sustained an ST-elevation myocardial infarction (STEMI). The nurse provides discharge teaching. Which statement, made by the patient, indicates that further teaching is required? A) "Medications are needed to prevent heart failure." B) "I will take aspirin, atenolol, and captopril indefinitely." C) "My blood pressure should be less than 130/80 mm Hg." D) "Daily estrogen will prevent another heart attack."

Oxygen demand and oxygen supply... lack of blood flow!

A myocardial injury is ultimately the result of an imbalance between what?

The answer is B. Glycoprotein IIb/IIIa inhibitors (for example, abciximab) are powerful intravenous antiplatelet drugs that can enhance the benefits of primary percutaneous coronary intervention (PCI). Treatment with abciximab should begin as soon as possible before PCI and should continue for 12 hours afterward.

A patient diagnosed with ST-elevation myocardial infarction has been scheduled for an angioplasty. Which medication does the nurse anticipate administering before this procedure? A) Dobutamine [Dobutrex] B) Abciximab [ReoPro] C) Alteplase [Activase] D) Warfarin [Coumadin]

The answer is C. Aspirin, beta blocker, oxygen, morphine, and nitroglycerin are considered routine therapy for patients with ST-elevation myocardial infarction.

A patient has been diagnosed with a STEMI. Which medications does the nurse expect to be prescribed for this patient? A) Beta blocker, angiotensin II receptor blocker, and oxygen B) Aspirin, angiotensin-converting enzyme inhibitor, and diuretics C) Aspirin, beta blocker, oxygen, morphine, and nitroglycerin D) Heparin, nitroprusside, morphine, and calcium channel blocker.

The answer is D. The first dose of aspirin should be given immediately. The dose (162-325 mg) is chewed to allow rapid absorption across the buccal mucosa. Aspirin suppresses platelet aggregation and thereby decreases mortality, reinfarction, and stroke. All patients should chew a 162- to 325-mg dose upon hospital admission and should take 81 to 162 mg/day indefinitely after discharge.

A patient in the emergency department is diagnosed with ST-Elevation Myocardial Infarction (STEMI). The patient has been prescribed 325mg of aspirin. Which action by the nurse is appropriate? A) Administer the medication to the patient if a headache develops. B) Administer the medication with a full glass of water. C) Instruct the patient to let the tablet dissolve under the tongue. D) Tell the patient to chew the tablet thoroughly.

The answer is B. The first dose of aspirin (162 to 325 mg) should be given immediately after the onset of symptoms or as soon as possible. Each baby aspirin (81 mg) should be chewed to allow rapid absorption across the buccal mucosa. Nonsteroidal antiinflammatory drugs (NSAIDs), such as ibuprofen, are avoided, because they increase the risk of mortality, reinfarction, hypertension, heart failure, and myocardial rupture. Current guidelines recommend administration of oxygen by nasal cannula only if the arterial oxygen saturation is below 90%. Treatment with ACE inhibitors should begin within 24 hours of symptom onset.

A patient is admitted to the emergency department complaining of chest pain, and the electrocardiogram (ECG) shows an evolving ST-segment elevation myocardial infarction (STEMI). What intervention should the nurse anticipate? A) Administer 400 mg of ibuprofen. B) Have the patient chew a 325-mg aspirin. C) Administer an ACE inhibitor within 1 week of the onset of chest pain. D) Provide oxygen by nasal cannula to achieve an arterial oxygen saturation of 94%.

The answer is A. In this situation, the nurse's top priority is to have the patient chew a 325-mg aspirin. Several other nursing actions also are important in patients with STEMI, including oxygen administration, morphine for pain relief and venodilation, beta blockers and nitroglycerin to improve hemodynamics, and reperfusion therapy by means of percutaneous intervention or fibrinolytics. Meperidine would not be an analgesic of choice. Verapamil is a calcium channel blocker, and these drugs are no longer considered beneficial in patients with STEMI. Most agents used for STEMI do not cause hyperglycemia; therefore, an insulin drip is not indicated.

A patient is admitted to the emergency department with a diagnosis of ST-segment elevation myocardial infarction (STEMI). Which is the priority nursing action? A) Having the patient chew a 325-mg aspirin B) Administering meperidine [Demerol] for pain relief C) Giving verapamil [Calan] to lower blood pressure D) Preparing an insulin drip to manage complications

-Primary percutaneous coronary intervention (putting in a stent) -Fibrinolytic (thrombolytic) therapy. Dissolves clots.

How do we manage STEMI with reperfusion therapy?

An anticoagulant (IV heparin) and antiplatelet drugs (aspirin)

All patients undergoing fibrinolytic therapy should receive what?

MONA B -Morphine -Oxygen -Nitroglycerin -Aspirin (acts as blood thinner... antiplatelet) -Beta blockers (-olol)

How do we manage STEMI with routine drug therapy?

-Unfractionated heparin used for treatment lasting less than 48 hours -Low-molecular-weight heparin used for treatment lasting longer than 48 hours. -Antiplatelet drugs -Low-dose aspirin used indefinitely

How do we manage a patient after immediately performing reperfusion therapy as a result from a STEMI?

The right coronary artery. It feeds the SA node, but it doesn't influence a lot of pumping action. So, a pace maker could help you after the attack.

If you had to pick which artery to clog, which one would you choose?

Redistribution of ions takes place. (Hydrogen ions accumulate in the myocardium and calcium ions become sequestered in mitochondria. The resultant acidosis and functional calcium deficiency alter the distensibility of cardiac muscle. Sodium ions accumulate in myocardial cells and promote edema. Potassium ions are lost from myocardial cells, setting the stage for dysrhythmias.)

In response to local ischemia, a dramatic redistribution of what occurs?

-Thienopyridines -**Aspirin: low-dose (baby) aspirin. 81-162mg/day. Should be taken indefinitely by all who have had an MI.

Post STEMI, how do we manage a patient with antiplatelet drugs?

The answers are A, C, D, E. Patients experiencing STEMI typically present with chest pain, an elevated ST segment on the ECG, elevated levels of cardiac cell components (eg, troponin and creatinine kinase), sweating, weakness, and a sense of impending doom.

The nurse in the emergency department is receiving a report on a patient diagnosed with ST-elevation myocardial infarction (STEMI). What are the common biochemical markers and symptoms for a STEMI? (Select all that apply.) A) Chest pain and electrocardiographic (ECG) changes B) Decreased troponin I level C) Elevated troponin T level D) Elevated creatinine kinase level E) Weakness and diaphoresis

The answer is C. Nitroglycerin should be avoided in patients with hypotension (systolic BP below 90 mm Hg), severe bradycardia (heart rate below 50 beats per minute), marked tachycardia (heart rate above 100 beats per minute), or suspected right ventricular infarction. If the patient has taken sildenafil, avanafil, or vardenafil in the past 24 hours or tadalafil in the past 48 hours, nitroglycerin should not be given. According to current guidelines, the patient should receive 3 doses of sublingual nitroglycerin before a continuous infusion is considered. Signs of pulmonary congestion also warrant use of IV nitroglycerin.

The nurse is preparing to administer an intravenous (IV) nitroglycerin infusion. For which patient should the nurse question the healthcare provider's prescription to administer IV nitroglycerin infusion? A) A patient with an inferior wall myocardial infarction (MI); blood pressure of 170/60 mm Hg B) A patient with an anterior wall MI who has pulmonary congestion; heart rate of 92 beats per minute C) A patient with a right ventricular infarction, confirmed by right-sided ECG changes D) A patient with chest pain unrelieved to 3 sublingual nitroglycerin tablets; took tadalafil 4 days ago

The answer is A. All post-MI patients should take a beta blocker (metoprolol), an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB), and an antiplatelet or anticoagulant agent. Although the other agents may be warranted, these three categories are universally indicated after an MI.

The nurse is teaching a patient who has had an ST-segment elevation myocardial infarction (STEMI) about home medications. Which agent represents a drug category that should be taken by all post-MI patients? A) Metoprolol [Lopressor] B) Hydrochlorothiazide (HCTZ) C) Diltiazem [Cardizem] D) Lovastatin [Mevacor]

The answer is D. The priority treatment of ventricular fibrillation involves defibrillation, followed by intravenous (IV) amiodarone infusion for 24 to 48 hours. The other agents may be used in the treatment of a patient with MI, but amiodarone is the specific agent used to treat ventricular fibrillation.

The nurse understands that ventricular fibrillation is a common cause of death after myocardial infarction (MI). Which drug should be readily available to treat ventricular fibrillation? A) Propranolol [Inderal] B) Dobutamine C) Valsartan [Diovan] D) Amiodarone [Cordarone]

-Ventricular dysrhythmias -Cardiogenic shock -heart failure -Cardiac rupture

What are some complications of having a STEMI?

-Cardiac troponin I and cardiac troponin T -MB isozyme of creatine kinase

What are the biochemical markers for MI?

-Chest pain -Characteristic ECG change (elevation of ST segment) -Sweating, weakness, sense of impending doom

What diagnoses a STEMI?

Decrease short-term mortality in all patients and long-term mortality in patients with reduced left ventricular (LV) function.

What do Angiotensin-converting enzyme (ACE) inhibitors aim to do?

-Beta blocker -ACE inhibitor -Antiplatelet drug/anticoagulant -Statin

What four drugs should be taken indefinitely after having a STEMI?

The use of angioplasty rather than fibrinolytic therapy to create reperfusion. A stent may be placed.

What is a Primary Percutaneous Coronary Intervention?

Necrosis of the myocardium resulting in ischemia. It's the heart muscle dying.

What is a myocardial infarction (MI)?

Acute MI caused by complete interruption of regional myocardial blood flow. Causes elevation of the ST segment on the ECG (electrocardiogram)

What is an ST-Elevation Myocardial Infarction (STEMI)?

Re-establishment of blood flow to the area of the myocardium that is currently ischemic.

What is reperfusion?

Primary PCI within 90 minutes of patient contact.

What is the desired amount of time, or goal time, to put in a Primary PCI (Primary percutaneous coronary intervention)?

Blood flow to a region of myocardium is blocked by platelet plugging and thrombus formation.

What is the pathophysiology of a STEMI? How does blood flow get blocked?

30 minutes or less

What is the target time for a patient to enter the emergency department and start fibrinolysis?

20%

What percentage of patients with STEMI experience no symptoms?

-Right coronary artery -Left anterior descending artery -Circumflex artery

What three main arteries could get blocked by platelet plugging and thrombus formation, causing a STEMI?

Used when we can't get a patient to a cath lab.

When is Fibrinolytic (Thrombolytic) Therapy used?

The answer is B. The major complication of thrombolytic therapy is bleeding. Intracranial hemorrhage (ICH) is the greatest concern.

Which adverse effect is the greatest concern with thrombolytic therapy? A) Anaphylaxis B) Intracranial hemorrhage C) Cerebral edema D) Hemophilia

The answer is C. Diltiazem is not indicated for a patient undergoing primary PCI. All patients undergoing PCI should receive an anticoagulant (IV heparin, bivalirudin) combined with antiplatelet drugs: aspirin plus either clopidogrel, ticagrelor, or prasugrel.

Which drug would not be included in the treatment plan for a patient who will undergo a primary percutaneous coronary intervention (PCI)? A) Aspirin B) Heparin C) Diltiazem [Cardizem] D) Clopidogrel [Plavix]

The answer is C. Reperfusion therapy restores blood flow through the blocked coronary arteries responsible for the MI. Reperfusion therapy can be accomplished through percutaneous coronary intervention or fibrinolytic therapy.

Which is the most beneficial treatment for patients experiencing an ST-segment elevation myocardial infarction (STEMI)? A) Oxygen administration B) Metoprolol [Lopressor] C) Reperfusion therapy D) Lidocaine [Xylocaine]

The answer is C. Morphine improves hemodynamics. By promoting venodilation, the drug reduces cardiac preload. By promoting modest arterial dilation, it may cause some reduction in afterload. The combined reductions in preload and afterload lower the cardiac oxygen demand, thereby helping to preserve the ischemic myocardium and relieving the patient's pain.

Which medication is the treatment of choice for ST-segment elevation myocardial infarction (STEMI)-associated pain? A) Aspirin B) Lorazepam [Ativan] C) Morphine D) Hydromorphone hydrochloride [Dilaudid]

The statin not only keeps the blood cholesterol under control, but it prevents the rupture of plaque... stabilizes plaque.

Why would a patient who suffered from a STEMI take a statin indefinitely after the incident?