myocardial infraction: intro, pathophysiology, clinical manifestations, diagnostic tests, medical and nursing management
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S.N O. SPECIFIC OBJECTIVE CONTENT MATTER TEACHING LEARNING ACTIVITIES EVALUATION 1. 2. 3. Define Myocardial infarction. Enlist the risk factors of Myocardial infarction. MYOCARDIAL INFARCTION Myocardial infarction is leading cause of sudden death in men and women. It is caused by an obstruction in a coronary artery resulting in necrosis to the tissues supplied by the artery. The obstruction is usually due atherosclerotic plaque, a thrombus or an embolism. The area most affected is left ventricle. INTRODUCTION The heart muscle must have adequate blood supply to contract properly. The coronary arteries carry oxygen to the myocardium. When coronary arteries are narrowed or blocked the area of heart muscle supplied by that artery becomes ischemic and injured which gives rise to various disease conditions. The student teacher defines MI verbally. What do you mean by Myocardial infarction? What are the various risk factors of
Transcript
1. S.NO. SPECIFIC OBJECTIVE CONTENT MATTER TEACHING LEARNING
ACTIVITIES INTRODUCTION The heart muscle must have adequate blood
supply to contract properly. The coronary arteries carry oxygen to
the myocardium. When coronary arteries are narrowed or blocked the
area of heart muscle supplied by that artery becomes ischemic and
injured which gives rise to various disease conditions. EVALUATION
MYOCARDIAL INFARCTION Myocardial infarction is leading cause of
sudden death in men and women. It is caused by an obstruction in a
coronary artery resulting in necrosis to the tissues supplied by
the artery. The obstruction is usually due atherosclerotic plaque,
a thrombus or an embolism. The area most affected is left
ventricle. The student teacher defines MI verbally. What do you
mean by Myocardial infarction? 1. 2. 3. Define Myocardial
infarction. Enlist the risk factors of Myocardial infarction. RISK
FACTORS NON-MODIFIABLE RISK FACTORS:-Family history -Increasing age
-Race The student teacher enumerates the risk factors of MI on PPT.
What are the various risk factors of MI.
2. -Male gender MODIFIABLE RISK FACTORS:-Blood lipid level
abnormalities -Diabetes mellitus -Hypertension -Physical inactivity
-Obesity -Cigarette smoking -Alcohol consumption 4. 5. Describe the
pathophysiology of MI in detail. PATHOPHYSIOLOGY Enumerate the
clinical manifestations of MI CLINICAL MANIFESTATIONS
Cardiovascular -Chest pain or discomfort, palpitations. -Increased
blood pressure. -pulse deficit In an MI, an area of myocardium is
permanently destroyed. MI is usually caused by reduced blood flow
in a coronary artery due to rupture of atherosclerotic plaque and
subsequent occlusion of artery by the thrombus. Other causes of MI
are vasospasm of coronary artery, decreased oxygen supply, and
increased demand for oxygen. In each case a profound imbalance
exists between myocardial supply and demand. The area of infarction
develops over minutes to hour. As the cells are deprived of oxygen,
ischemia develops and cellular injury occurs and lack of oxygen
results in infarction. The student teacher explains What are the
pathophysiology by using pathophysiological ppt. Changes occurring
in MI? The student teacher enumerates the clinical manifestations
by using ppt. What are the clinical manifestations of MI?
3. -ST segment and T wave changes. Respiratory -Shortness of
breath -Dyspnea,tachypnea -crackles -pulmonary edema
Gastrointestinal -nausea and vomiting Genitourinary -Decreased
urinary output indicates cardiogenic shock. Skin -cool,clammy
,diaphoretic and pale appearance due to sympathetic stimulation may
indicate cardiogenic shock Neurologic -Anxiety,restlessness,light
headedeness Psychological -Fear with feeling of impending doom. 6.
Discuss the assessment and diagnostic findings of MI ASSESSMENT AND
DIAGNOSTIC FINDINGS The diagnosis of MI is based on the presenting
symptoms and laboratory test results.The prognosis depends on the
severity of coronary artery obstruction and extent of myocardial
damage. Physical examination is always conducted.but the
examination alone does not confirm the diagnosis. Patients
history:The patients history has two parts:the description of the
presenting symptoms and the history of previous illness and family
The student teacher discusses the diagnostic techniques with the
help of ppt and lecture cum discussion What are the diagnostics
measures used to diagnose MI?
4. history of heart disease.Previous history also include the
risk factors for heart disease. Electrocardiogram:The ECG provides
the information that assist in diagnosing acute MI. It should be
obtained within 10 minutes from the time the patient reports the
pain or arrives the emergency department. By monitoring ECG changes
over time, the location, evolution and resolution of an MI can be
identified and monitored. The classic ECG changes are T wave
inversion, ST segment elevation and development of abnormal Q wave
.During recovery from MI the ST segment often is the first ECG
indicator to return to normal. Echocardiogram:The echocardiogram is
used to evaluate ventricular function.It may be used to assist in
diagnosing an MI especially when ECG is nondiagnoctic.The
echocardiogram can detect hypokinetic and akinetic wall motion and
can determine the ejection fraction. Laboratory tests:Creatinine
kinase and its isoenzymes:Ck-MB is the cardiac-specific
isoenzyme,found in cardiac cells. Elevated CK-MB assessed by mass
assay is an indicator of acute MI;its level begins to rise within a
few hours and peaks within 24 hours of an MI. Myoglobin: Myoglobin
is heme protein helps transport oxygen.It is found in cardiac cells
and skeletal
5. muscle.It starts to oncrease within 1-3 hours and peaks
within 12 hours after onset of symptoms. Troponin:It is a protein
found in the myocardium regulates the contractile process.There are
three isomers of troponin C,I and T. Troponin I and T are specific
for cardiac muscles and these tests are currently recognised as
reliable and critical markers of myocardial injury.An increased
level of troponins in serum can be detected within few hours during
acute MI. It remains elevated for a long period often as long as 3
weeks and can be used to detect recent myocardial damage. 7. Enlist
the complications of MI COMPLICATIONS Acute pulmonary edema Heart
failure Cardiogenic shock Dysrhythmias Pericardial effusion
Myocardial rupture The student teacher enlists the complications
with the help of chart What are the complications of MI? 8. Explain
the medical management of the patient with MI. MEDICAL/SURGICAL
MANAGEMENT It focuses on reducing the workload of heart,relieving
pain,improving tissue perfusion,preventing complications and
further tissue damage.Immediately after MI a client is admitted to
a coronary unit.The client heart is contantly monitored for
dysrhythmias.The clients vital signs are The student teacher
describes the medical management with the help of ppt. What can be
the medical management of the patient with MI?
6. monitored by arterial line for hemodynamic monitoring or
noninvasive B.P monitoring system. Pharmacological therapy:The
patient with MI is given aspirin,nitroglycerin,morphine,beta
blockers and other medications as indicated.Patients should receive
beta blockers initially,throughout the hospitalisation and after
discharge.These medications decrease the incidence of future
cardiac events. Thrombolytics:These medications are administered
I/V , can be given directly into coronary artery in cardiac
catheterization lab. The purpose of thrombolytics is to dissolve
and luse the thrombus in a coronary artery,causing reperfusion and
minimize the size of infarction. Analgesics:The analgesics of
choice for acute MI is morphine sulphate administered in I/V
boluses to decrease pain and anxiety.It decreases the preload and
afterload thus decreasing the workload of heart.It also relax the
bronchioles to enhance the oxygenation.The cardiovascular response
to morphine is monitored closely,particularly B.P which can
decrease and repiratory rate can be depressed. ACE inhibitors:ACE
inhibitors prevent the conversion of
7. angiotensin I to angiotensin II.In the absence of
angiotensin II B.P will decrease and kidneys excrete sodium and
fluid which further decreases the oxygen demand of the heart.
Antidysrhythmic agents:Three dysrhythmias may occur following an MI
are: ventricular fibrillation, bradycardias, tachycardias.
Ventricular fibrillation is treated with defibrillation. Atropine
and if needed a temporary pacemaker may be inserted for
bradycardias. Two tachycardias that may occur are atrial
fibrillation and ventricular tachycardia. Atrial tachycardias is
treated with digoxin or amiodrone. Ventricular tachycardias is
treated with lidocaine or cardioversion.If the dysrhythmias are
continous then magnesium sulphate can be given. Medical treatment
guidelines for acute myocardial infarction:-Use rapid transit to
the hospital -Obtain 12-lead ECG to read within 10 minutes. -Obtain
laboratory blood specimens of cardiac biomarkers, including
troponins. -Obtain other diagnostics to clarify diagnosis. Begin
routine medical interventions:-Supplemental oxygen -Nitroglycerin
-Morphine -Aspirin 162-325mg -Beta blockers
8. -Angiotensin converting enzyme inhibitors within 24 hours.
Evaluate for indications for reperfusion therapy:-Percutaneous
coronary intervention -Thrombolytic therapy Continue therapy as
indicated:-I/V heparin/low molecular weight heparin -Clopidogrel or
ticlopidine -Glycoprotein IIb/IIIa inhibitor -Bed rest(12-24 hours)
Emergent percutaneous coronary intervention:-The patient in whom an
acute MI is suspected may be referred for an immediate PCI.PCI may
be used to open the occluded coronary artery in an acute MI and
promote reperfusion. To the area that has been deprived of
oxygen.Supirior outcomes have been reported with the use of PCI
compared to thrombolytics.PCI treats the underlying atherosclerotic
lesions.Because the duration of oxygen deprivation is directly
related to number of cells that die,the time from the patients
arrival in the emergency department to time PCI is performed should
be less than 60 minutes.This is frequently referred door to balloon
time.Cardiac catheterization lab and staff must be available if an
emergent PCI is performed within short time.
9. NURSING MANAGEMENT Elaborate the nursing management of the
patient with MI in detail The nursing priorities are 1) To relieve
pain, anxiety. 2)To reduce myocardial workload.' 3)To prevent and
assist in treatment of life threatening disarrythmias. 4) To
promote self care. NURSING DIAGNOSIS, INTERVENTION AND RATIONALE I.
Pain related to tissue ischemia secondary.to coronary occlusion
manifested by complaints of chest pain, facial grimacing.
Intervention: Obtain full description of pain from patient
including location, intensity, duration, quality and radiation.
Rationale: Pain is a subjective symptom and must be described by
the patient. Intervention: .Instruct patient to report pain
immediately. Rationale: Delay in reporting pain hinders pain
relief. Intervention: Provide calm and quiet The student teacher
elaborates the nursing management with the help of ppt. What will
the nursing care of the patient with MI?
10. environment and other comfort measures. Rationale:
Decreased external stimuli may aggravate anxiety. Intervention:
Administer supplementary oxygen. Rationale: Increases the oxygen
supply to myocardium thereby relieving discomfort. II. Anxiety /
fear related to change in health and socio economic status
manifested by apprehension, increased tension, restlessness,
uncertainty etc. Interventions: Note presence of hostility
withdrawal or denial. Rationale: Ongoing anxiety may be present
manifested by depression. Intervention: Encourage patient to
communicate with one another, sharing questions. Rationale: Sharing
information may relieve tension of unexpressed worries.
Intervention: Answer all questions honestly. Rationale: To win the
confidence of the patient.
11. III. Altered tissue perfusion related to reduction of blood
flow due to vaso constriction manifested by thrombo embolitic
formation. Interventions: Inspect for cyanosis, cold and clammy
skin. Rationale: Systemic vasoconstriction resulting from decreased
cardiac output may be evidenced by decreased skin perfusion.
Intervention: Assess for homan's sign, erythema and edema.
Rationale: Indicator for deep vein thrombosis. Interventions:
Monitor laboratory details eg: ABG' S BUN Indicators of organ
perfusion. Prepare the patient for thromboembolytic therapy.
Rationale: To dissolve the clot and to restore perfusion of
myocardium. IV. Excess fluid volume related to increased sodium and
water retention manifested by dependent edema. Interventions:
Measure intake output to detect whether there is decrease in
output. Rationale: Decreased cardiac output results in impaired
kidney perfusion. Na/H2o retention
12. and reduced urine output. Intervention: Weigh daily
Rationale: Sudden changes in weight indicate fluid imbalance.
Intervention: Provide low sodium diet. Rationale: Sodium will
enhance fluid retention. Intervention: Note the development of
dependent edema. Rationale: Indicates development of CHF.
Intervention: Administer diuretics as prescribed. Rationale: To
correct fluid overload. V. Knowledge deficit related to lack of
factual information regarding implications of heart disease and
future health status manifested by anxiety, worries, gloomy face
etc. Interventions: Assess patient's level -of knowledge and
ability to learn. Rationale: It is necessary to create individual
instruction plan. Intervention: Educate the patient about basic
informations regarding M.I., its cause,
13. prevention and management. Rationale: Patient will gain
adequate knowledge about his disease and will try to avoid a second
attack. Intervention: Emphasize on the importance of avoiding the
risk factors of M.I. Rationale: Modifiable risk factors can be
prevented if we take adequate precautions. OTHER NURSING
MANAGEMENT: Provide semi-fowler's positions to promote chest
expansions and comfort. Oxygen administration to treat tissue
hypoxia. Check vital signs every 15 minutes. Watch for PVC
(Premature Ventricular Contractions) in the ECG. Assess the L.O.C.
Morphine is the drug of choice to relieve chest pain. Strict I/O
chart. Bed rest. Sedation and hypnotics to relieve unnecessary
anxiety. Clear liquid diet for 48 hours and thereafter soft bland
diet. Cardiac enzymes should be repeated. Educate the patient to
control diet high in fats and cholesterol. Summary: Today we have
dealt with: Definition of MI Risk factors Pathophysiology Clinical
manifestations
14. Diagnostic findings Medical management Nursing management
Conclusion : MI is a life threatening disease caused by many
factors. Health education must be given to the patients with
predisposing or risk factors to prevent it. Early diagnosis is also
very important for saving the life of the patient. BIBLIOGRAPHY:
1)Black M. Joyce ; Medical surgical nursing ; 5th edition ; W.B
Saunders Company ; Singapore 1980 ; pg no. 1238. 2)Spring house ;
handbook of medical surgical nursing ; 3rd edition ; Judith A.
Schilling McCann; Pennsylvania 1998 ; pg. No. 617-618. 3)Suddarths
and brunner; Textbook of medical surgical nursing; 11th edition;
Lippincott Williams and Wilkins ; United states of America 2009;
pg. No.
15. 4)White lois; Medical surgical nursing; Delmar publishers ;
india 1998; pg. No. 5)Lewis Mantik shoron; Medical surgical
nursing; 6th edition; Mosby Elsevier; United states of America
2004; pg. No. 6) www.findarticles.com 7)Sorensen and luckmann;
medical surgical nursing 4th edition; W.B sauders company; pg
no.-1150-1164 8)A Reference Manual of Nurses on Coronary Care
Nursing by Sister Nancy, Kumar Publishing House, Pg. No. 48-49.
9)www.medscape.com 10)www. jama.ama-assn.org