- Myocardial infarction, commonly known as a heart attack, is the death (necrosis) of a portion of heart muscle secondary to prolonged ischemia, due to the acute reduction or cessation of blood supply, which is most often caused by atherosclerotic plaque rupture with thrombus formation in a coronary vessel, and sometime severe vasospasm (sudden constriction or narrowing) of a coronary (rare).
Etiology
- Atherosclerotic plaque rupture with thrombus formation – Most common cause
- Severe vasospasm (sudden constriction or narrowing) of a coronary (rare) eg, acute blood loss, anemia, or low blood pressure)
Classification
There are two basic types of myocardial infarction based on pathology:
-
Transmural
- associated with atherosclerosis involving a major coronary artery.
- It can be subclassified into anterior, posterior, inferior, lateral or septal.
- It infarcts extend through the whole thickness of the heart muscle and are usually a result of complete occlusion of the area's blood supply.
- ECG:- ST elevation and Q waves are seen.
-
Subendocardial
- involving a small area in the subendocardial wall of the left ventricle, ventricular septum, or papillary muscles.
- The subendocardial area is particularly susceptible to ischemia.
- ECG:- ST depression.
Clinical, there are two types of myocardial infarction based on ECG changes:
Clinical Manifestations
-
Pain
- Client may experience crushing substernal pain.
- Pain may radiate to the jaw, back, and left arm.
- Pain may occur without cause, primarily early in the morning.
- Pain is unrelieved by rest or nitroglycerin and is relieved only by opioids.
- Pain lasts 30 minutes or longer.
- Dyspnea
- Increase in blood pressure (initial sign) gradually drop the blood pressure
- Nausea and vomiting
- Ashen skin (pale), cool, clammy, diaphoretic
- Hyperthermia
- Mild restlessness and apprehension, anxiety, visual disturbances, altered speech
- Tachypnea bradycardia
- Dysrhythmias
- Sometimes May be a symptomatic
Diagnostic test
-
Electrocardiogram
- The injured myocardial cells depolarize normally but repolarize more rapidly than normal cells, causing the ST segment to rise at least 1 mm above the isoelectric line.
- Hours to days after the MI, ST and T wave changes will return to normal but the Q wave changes usually remains permanently.
-
White blood cell count –
- An elevated WBC count of 10,000 to 20,000/mm3 appears on the second day following the MI and lasts up to 1 week.
-
Echocardiogram
- The echocardiogram is used to evaluate ventricular function.
- It may be used to assist in diagnosing an MI, especially when the ECG is non-diagnostic.
Medical management
Treatment Guidelines for Acute Myocardial Infarction
- Use rapid transit to the hospital.
- Obtain 12-lead electrocardiogram (ECG) to be read within 10 minutes.
- Obtain laboratory blood specimens of cardiac biomarkers, including troponin.
- Obtain other diagnostics to clarify the diagnosis.
-
Begin routine medical interventions:
-
Evaluate for indications for reperfusion therapy:
- Percutaneous coronary intervention
- Thrombolytic therapy
-
Continue therapy as indicated:
- Intravenous heparin, low-molecular-weight heparin, bivalirudin, or fondaparinux
- Clopidogrel (Plavix)
- Glycoprotein IIb/IIIa inhibitor
- Bed rest for a minimum of 12 to 24 hours
THROMBOLYTIC AGENTS
NARCOTIC ANALGESICS
- {Morphine Sulfate}
-
Actions/Indications
- Used for pain associated with ischemia and is the analgesia of choice for STEMI.
- IV doses starting at 1 to 2 mg are used for patients whose chest pain/discomfort is not relieved with NTG or is recurrent despite antiischemic therapies.
- Morphine reduces myocardial oxygen demand because of its venodilation properties, modest reductions in heart rate (through increased vagal tone) and systolic BP, and stress reduction via pain relief.
-
Contraindications
- Patients with UA/NSTEMI, using caution when administering morphine to those patients.
-
Adverse Reactions.
- The major adverse reaction to morphine is –
- Hypotension especially in the presence of volume depletion and/or vasodilator therapy.
- Nausea and vomiting
- Respiratory depression is the most serious complication with severe hypoventilation requiring intubation.
-
Nursing Implications
- Patients who develop hypotension should be placed supine or in the Trendelenburg position, given IV saline boluses or infusions, and IV atropine if the hypotension is accompanied by bradycardia.
- Antiemetics are used to control nausea and vomiting.
- Naloxone (0.4 to 2.0 mg IV) may be administered for morphine overdose with respiratory or circulatory depressions. Other narcotics may be used for pain relief in patients allergic to morphine.
ANGIOTENSIN-CONVERTING ENZYME INHIBITORS
- (Captopril)
-
Action
- Angiotensin-converting enzyme (ACE) inhibitors prevent the conversion of angiotensin I to angiotensin II.In the absence of angiotensin II, the blood pressure decreases and the kidneys excrete sodium and fluid (diuresis), decreasing the oxygen demand of the heart.
-
Nursing Implication
- It is important to ensure that a patient is not hypotensive, hyponatremic, hypovolemic, or hyperkalemic before administering ACE inhibitors.
- Blood pressure, urine out-put, and serum sodium, potassium, and creatinine levels need to be monitored closely.
-
Other medication are –
- Vasodilators – Nitroglycerine, ISD (Isosorbide Dinitrate, Isordil)
- Anti Arrythmic Agents - Lidocaine (Xylocane), Brutylium
- Beta-blockers (-lol)
- Calcium Antagonist - amlodipine, verapamil, diltiazem
- Anti Coagulant
- Heparin (check for partial thrombin time) Antidote: protamine sulfate
- Coumadin/ Warfarin Sodium (check for prothrombin time) Antidote: Vitamin K
- Anti-Platelet – Aspirin (Anti-thrombotic effect)
-
General management
- Administer medication as ordered
- Administer oxygen low flow 2-4 L / min: to prevent respiratory arrest or dyspnea & prevent arrhythmias
- Enforce CBR in semi-fowlers position without bathroom privileges (use bedside commode): to decrease cardiac workload
- Instruct client to avoid forms of valsalva maneuver
- Place client on semi fowlers position
- Monitor strictly V/S, I&O, ECG tracing & hemodynamic procedures
- Perform complete lung / cardiovascular assessment regularly
- Monitor urinary output & report output of less than 30 ml/hr indicates decrease cardiac output
- Provide a full liquid diet with gradual increase to soft diet: low in saturated fats, Na & caffeine
- Maintain quiet environment
- Administer stool softeners as ordered: to facilitate bowel evacuation & prevent straining
- Relieve anxiety associated with coronary care unit (CCU) environment
Collaborative Problems/Potential Complications
- Acute pulmonary edema
- Heart failure
- Cardiogenic shock
- Dysrhythmias and cardiac arrest
- Pericardial effusion and cardiac tamponed
- Myocardial rupture
Nursing Management
Nursing Assessment
-
Gather information regarding the patient's chest pain:
-
Nature and intensity—describe the pain in patient's own words and compare it with pain previously experienced.
-
Onset and duration—exact time pain occurred as well as the time pain relieved or diminished (if applicable).
-
Location and radiation—point to the area where the pain is located and to other areas where the pain seems to travel.
-
Precipitating and aggravating factors—describe the activity performed just before the onset of pain and if any maneuvers and/or medications alleviated the pain.
-
Question patient about other symptoms experienced associated with the pain. Observe patient for diaphoresis, facial pallor, dyspnea, guarding behaviors, rigid body posture, extreme weakness, and confusion.
-
Evaluate cognitive, behavioral, and emotional status.
-
Question patient about prior health status with emphasis on current medications, allergies (opiate analgesics, iodine, shellfish), recent trauma or surgery, nonsteroidal anti-inflammatory drug (NSAID) ingestion, peptic ulcers, fainting spells, drug and alcohol use.
-
Analyze information for contraindications for thrombolytic therapy and PCI.
-
Gather information about presence or absence of cardiac risk factors.
-
Identify patient's social support system and potential caregivers.
-
Identify significant others' reaction to the crisis situation.
Nursing Diagnoses
-
Acute Pain related to oxygen supply and demand imbalance
-
Anxiety related to chest pain, fear of death, threatening environment
-
Decreased Cardiac Output related to impaired contractility
-
Activity Intolerance related to insufficient oxygenation to perform activities of daily living, deconditioning effects of bed rest
-
Risk for Injury (bleeding) related to dissolution of protective clots
-
Ineffective Tissue Perfusion (myocardial) related to coronary restenosis, extension of infarction
-
Ineffective Coping related to threats to self-esteem, disruption of sleep-rest pattern, lack of significant support system, and loss of control, change in lifestyle.
Nursing Interventions
Reducing Pain
-
Handle patient carefully while providing initial care, starting I.V. infusion, obtaining baseline vital signs, and attaching electrodes for continuous ECG monitoring.
-
Administer oxygen low inflow to prevent respiratory arrest at 2 – 4 L/min and Maintain oxygen saturation greater than 95%
-
Administer oxygen by nasal cannula.
-
Encourage patient to take deep breaths—may decrease incidence of dysrhythmias by allowing the heart to be less ischemic and less irritable; may reduce infarct size, decrease anxiety, and resolve chest pain.
-
Offer support and reassurance to patient that relief of pain is a priority.
-
Administer sublingual nitroglycerin as directed; recheck BP, heart rate, and respiratory rate before administering nitrate therapy and then 5 to 10 minutes after dose.
-
Administer opioids as prescribed (eg, morphine decreases sympathetic activity and reduces heart rate, respirations, BP, muscle tension, and anxiety; reduces preload and afterload).
-
Use caution when administering opioids to elderly patients and those with chronic obstructive pulmonary disease, hypotension, or dehydration.
-
Remember that meperidine is rarely used because it can have a vagolytic effect and cause tachycardia, thus increasing myocardial oxygen demands.
-
Obtain baseline vital signs before giving agents and 10 to 15 minutes after each dose. Place patient in a supine position during administration to minimize hypotension.
-
Give I.V. nitroglycerin as prescribed. Monitor BP continuously with automatic blood pressure machine (contraindicated with antithrombolytic therapy) or intraarterially or every 5 minutes with auscultatory method while titrating for pain relief.
-
Frequently review with patient the importance of reporting chest pain, discomfort, and epigastric distress without delay.
Alleviating Anxiety
-
Rule out physiologic etiologies for increasing or new onset anxiety before administering as-needed sedatives. Physiologic causes must be identified and treated in a timely fashion to prevent irreversible adverse or even fatal outcomes; sedatives may mask symptoms, delaying timely identification, diagnosis, and treatment.
-
Assess patient for signs of hypoperfusion, auscultate heart and lung sounds, obtain a rhythm strip, and administer oxygen as prescribed. Notify the health care provider immediately.
-
Document all assessment findings, health care provider notification and response, and interventions and response.
-
Explain to patient and family reasons for hospitalization, diagnostic tests, and therapies administered.
-
Explain equipment, procedures, and need for frequent assessment to patient and significant others.
-
Discuss with patient and family the anticipated nursing and medical regimen.
-
Observe for autonomic signs of anxiety, such as increases in heart rate, BP, respiratory rate, tremulousness.
-
Administer anti-anxiety agents as prescribed.
-
Explain to patient the reason for sedation: undue anxiety can make the heart more irritable and require more oxygen.
-
Assure patient that the goal of sedation is to promote comfort and, therefore, should be requested if anxious, excitable, or "jittery" feelings occur.
-
Observe for adverse effects of sedation, such as lethargy, confusion, and/or increased agitation.
-
Maintain consistency of care with one or two nurses regularly assisting patient, especially if severe anxiety is present.
-
Offer back massage to promote relaxation, reduce muscle tension, and improve skin integrity.
-
Use techniques, such as guided imagery, to relieve tension and anxiety.
Maintaining Hemodynamic Stability
-
Monitor BP every 2 hours or as directed—hypertension increases afterload of the heart, increasing oxygen demand; hypotension causes reduced coronary and tissue perfusion.
-
Monitor respirations and lung fields every 2 to 4 hours or as prescribed.
-
Auscultate for normal and abnormal breath sounds (crackles may indicate left-sided heart failure; diffuse crackles indicate pulmonary edema).
-
Observe for dyspnea, tachypnea, frothy pink sputum, orthopnea—may indicate left-sided heart failure, pulmonary embolus, pulmonary edema.
-
Evaluate heart rate and heart sounds every 2 to 4 hours or as directed.
-
Compare apical heart rate with radial pulse rate, and determine the pulse deficit.
-
Auscultate heart for the presence of a third heart sound (failing ventricle), fourth heart sound (stiffening ventricular muscle due to MI), friction rub (pericarditis), murmurs (valvular and papillary muscle dysfunction, intraventricular septal rupture).
-
Note presence of jugular vein distention and liver engorgement.
-
Evaluate the major arterial pulses (weak pulse and/or presence of pulsus alternans indicates decreased cardiac output (CO); irregularity results from dysrhythmias).
-
Take body temperature every 4 hours or as directed (most patients develop an increase in temperature within 24 to 48 hours due to tissue necrosis).
-
Monitor skin color and temperature (cool, clammy skin and pallor associated with vasoconstriction secondary to decreased CO).
-
Be alert to change in mental status, such as confusion, restlessness, disorientation.
-
Employ hemodynamic monitoring as indicated.
-
Evaluate urine output (30 mL/hour)—decrease in volume reflects a decrease in renal blood flow.
-
Monitor for life-threatening dysrhythmias (common within 24 hours following infarctions).
-
Be vigilant for occurrence of premature ventricular beats—may predict ventricular fibrillation or ventricular tachycardia.
-
Anticipate possibility of reperfusion dysrhythmias after thrombolytic therapy.
-
Correct dysrhythmias immediately as directed.
-
Monitor laboratory values, such as electrolytes, that could increase risk of dysrhythmias; report abnormalities promptly.
-
Keep emergency equipment at bedside (external defibrillator).
Increasing Activity Tolerance
-
Promote rest with early gradual increase in mobilization —prevents deconditioning, which occurs with bed rest.
-
Minimize environmental noise.
-
Provide a comfortable environmental temperature.
-
Avoid unnecessary interruptions and procedures.
-
Structure routine care measures to include rest periods after activity.
-
Discuss with patient and family the purpose of limited activity and visitors—to help the heart heal by lowering heart rate and BP, maintaining cardiac workload at lowest level, and decreasing oxygen consumption.
-
Promote restful diversional activities for patient (reading, listening to music, drawing, crossword puzzles, crafts).
-
Encourage frequent position changes while in bed.
-
Assist patient with prescribed activities.
-
Assist patient to rise slowly from a supine position to minimize orthostatic hypotension related to medications.
-
Encourage passive and active range-of-motion (ROM) exercise as directed while on bed rest.
-
Measure the length and width of the unit so patients can gradually increase their activity levels with specific guidelines (walk one width [150 ft] of the unit).
-
Elevate patient's feet when out of bed in chair to promote venous return.
-
Implement a step-by-step program for progressive activity as directed. Typically can progress to the next step if they are free from chest pain and ECG changes during the activity.
Preventing Bleeding
-
Take vital signs every 15 minutes during infusion of thrombolytic agent and then hourly.
-
Observe for hematomas or skin breakdown, especially in potential pressure areas such as the sacrum, back, elbows, ankles.
-
Be alert to verbal complaints of back pain indicative of possible retroperitoneal bleeding.
-
Observe all puncture sites every 15 minutes during infusion of thrombolytic therapy and then hourly for bleeding.
-
Apply manual pressure to venous or arterial sites if bleeding occurs. Use pressure dressings for coverage of all access sites.
-
Observe for blood in stool, emesis, urine, and sputum.
-
Minimize venipunctures and arterial punctures; use heparin lock for blood sampling and medication administration.
-
Avoid I.M. injections.
-
Caution patient about vigorous tooth brushing, hair combing, or shaving.
-
Avoid trauma to patient by minimizing frequent handling of patient.
-
Monitor laboratory values: PT, International Normalized Ratio (INR), PTT, hematocrit (HCT), and hemoglobin.
-
Check for current blood type and crossmatch.
-
Administer antacids or GI prophylaxis, as directed, to prevent stress ulcers.
-
Implement emergency interventions, as directed, in the event of bleeding: fluid, volume expanders, blood products.
-
Monitor for changes in mental status and headache.
-
Avoid vigorous oral suctioning.
-
Avoid use of automatic BP device above puncture sites or hematoma. Use care in taking BP; use arm not being used for thrombolytic therapy.
Maintaining Tissue Perfusion
-
Observe for persistent and/or recurrence of signs and symptoms of ischemia, including chest pain, diaphoresis, hypotension—may indicate extension of MI and/or reocclusion of coronary vessel.
-
Report immediately.
-
Administer oxygen as directed.
-
Record a 12-lead ECG.
-
Prepare patient for possible emergency procedures: cardiac catheterization, bypass surgery, PCI, thrombolytic therapy, intra-aortic balloon pump.
Strengthening Coping Abilities
-
Listen carefully to patient and family to ascertain their cognitive appraisals of stressors and threats.
-
Assist patient to establish a positive attitude toward illness and progress adaptively through the grieving process.
-
Manipulate environment to promote restful sleep by maintaining patient's usual sleep patterns.
-
Be alert to signs and symptoms of sleep deprivation—irritability, disorientation, hallucinations, diminished pain tolerance, aggressiveness.
-
Minimize possible adverse emotional response to transfer from the intensive care unit to the intermediate care unit:
-
Introduce the admitting nurse from the intermediate care unit to the patient before transfer.
-
Plan for the intermediate care nurse to answer questions the patient may have and to inform patient what to expect relative to physical layout of unit, nursing routines, and visiting hours.
Health Education
Goals are to restore patient to optimal physiologic, psychological, social, and work level; to aid in restoring confidence and self-esteem; to develop patient's self-monitoring skills; to assist in managing cardiac problems; and to modify risk factors.
-
Inform the patient and family about what has happened to patient's heart.
-
Explain basic cardiac anatomy and physiology.
-
Identify the difference between angina and MI.
-
Describe how the heart heals and that healing will not be complete for 6 to 8 weeks after infarction.
-
Discuss what the patient can do to assist in the recovery process and reduce the chance of future heart attacks.
-
Instruct patient on how to judge the body's response to activity.
-
Introduce the concept that different activities require varying expenditures of oxygen.
-
Emphasize the importance of rest and relaxation alternating with activity.
-
Instruct patient how to take pulse before and after activity as well as guidelines for the acceptable increases in heart rate that should occur.
-
Review signs and symptoms indicative of a poor response to increased activity levels: chest pain, extreme fatigue, shortness of breath.
-
Design an individualized activity progression program for patient as directed.
-
Determine activity levels appropriate for patient, as prescribed, and by predischarge low-level exercise stress test.
-
Encourage patient to list activities he enjoys and would like to resume.
-
Establish the energy expenditure of each activity (ie, which are most demanding on the heart), and rank activities from lowest to highest.
-
Instruct patient to move from one activity to another after the heart has been able to manage the previous workload as determined by signs and symptoms and pulse rate.
-
Give patient specific activity guidelines, and explain that activity guidelines will be reevaluated after heart heals:
-
Walk daily, gradually increasing distance and time as prescribed.
-
Avoid activities that tense muscles, such as weight lifting, lifting heavy objects, isometric exercises, pushing and/or pulling heavy loads, all of which can cause vagal stimulation.
-
Avoid working with arms overhead.
-
Gradually return to work.
-
Avoid extremes in temperature.
-
Do not rush; avoid tension.
-
Advise getting at least 7 hours of sleep each night and take 20- to 30-minute rest periods twice per day.
-
Advise limiting visitors to three to four daily for 15 to 30 minutes and shorten phone conversations.
-
Tell patient that sexual relations may be resumed on advice of health care provider, usually after exercise tolerance is assessed.
-
If patient can walk briskly or climb two flights of stairs, can usually resume sexual activity; resumption of sexual activity parallels resumption of usual activities.
-
Sexual activity should be avoided after eating a heavy meal, after drinking alcohol, or when tired.
-
Discuss impotence as an adverse effect of drug therapy and PDe5 contraindications.
-
Advise eating three to four small meals per day rather than large, heavy meals. Rest for 1 hour after meals.
-
Advise limiting caffeine and alcohol intake.
-
Driving a car must be cleared with health care provider at a follow-up visit.
-
Teach patient about medication regimen and adverse effects.
-
Instruct the patient to immediate contact with the doctor when the
-
Instruct the patient to notify health care provider when the following symptoms appear:
-
Assist patient to reduce risk of another MI by risk factor modification.
- Enrollment of client in a cardiac rehabilitation program
- Strict compliance to mediation & importance of follow up care
PROGNOSIS
The expected outcome varies with the amount and location of damaged tissue. The outcome is worse if there is damage to the electrical conduction system. Approximately one-third of cases are fatal. If the person is alive 2 hours after an attack, the probable outcome for survival is good, but may include complications. Uncomplicated cases may recover fully; heart attacks are not necessarily disabling. Usually the person can gradually resume normal activity and lifestyle.
Bibliography
-
Boon N. Davidson's principles & practice of medicine. 20th ed. Edinburgh, New York, Elsevier/Churchill Livingstone; 2006. Page no. – 591-600
-
Doenges M, Moorhouse M, Murr A. Nursing Care Plans: Guidelines for Individualizing Client Care Across the Life Span. 8th ed. F.A. Davis Company; 2009. Page no. – 74-88
-
Krapp KM. The Gale Encyclopedia of Nursing and Allied Health. 1st ed. Thomson Gale; 2001. Page no. – 1646-1651
-
Nettina SM. Lippincott Manual of Nursing Practice. Ninth Edition. Lippincott Williams & Wilkins; 2009. Page no. – 390-400
-
Smeltzer SC, Bare BG, Hinkle JL, Cheever KH. Brunner and Suddarth's Textbook of Medical-Surgical Nursing, 11th Edition. Lippincott Williams & Wilkins; 2006. Page no. – 874-885
-
Springhouse. Handbook of Medical-Surgical Nursing. Fourth. Lippincott Williams & Wilkins; 2005. Page no. – 598-605
-
Williams LS. Understanding Medical Surgical Nursing, 3rd Edition, F. A. Davis Co.; 2007. Page no. – 418-430
-
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001246/
-
http://en.wikipedia.org/wiki/Myocardial_infarction
-
http://www.medicinenet.com/heart_attack/article.htm
-
http://www.nlm.nih.gov/medlineplus/ency/article/000195.htm
-
http://emedicine.medscape.com/article/155919-overview
Army Jobs
ReplyDeleteComputer Operator
Data Entry
Click Here
Read More
Find Out More
Learn More
Crucial online marketing you just it applies seek before submission. It will probably be simple and easy to jot down advanced write-up which. Nausea
ReplyDelete