Myocardial infarction (MI) or acute Myocardial infarction is an acute coronary syndrome, results from reduced blood flow through one or more coronary arteries, which causes myocardial ischemia and necrosis. Myocardial infarction (MI) results when myocardial tissue becomes necrotic because of absent or diminished blood supply. When myocardial tissue is deprived of oxygenated blood supply for a period of time, an area of myocardial necrosis develops; this necrosis is surrounded by injured and ischemic tissue.
The infarction site depends on the vessels involved. For instance:
- Occlusion of the circumflex coronary artery causes a lateral Myocardial infarction (MI).
- Occlusion of the left anterior coronary artery causes an anterior Myocardial infarction (MI).
- Occlusion of the right coronary artery or one of its branches causes True posterior and inferior Myocardial infarction (MI)
- Right ventricular infarctions can also result from right coronary artery occlusion, can accompany inferior MI, and may cause right-sided heart failure.
- If a thrombus partially occludes a coronary vessel, distal microthrombi may cause necrosis in some myocytes, leading to a non-ST-segment elevation MI (NSTEMI).
- If a thrombus fully occludes the vessel for a prolonged time, an ST-segment elevation MI (STEMI) usually develops.
Men are more susceptible to Myocardial infarction (MI) than premenopausal women, although incidence is rising among women who smoke and take a hormonal contraceptive. The incidence in postmenopausal women resembles that in men.
Causes for Myocardial Infarction (MI)
A Myocardial infarction (MI) results from occlusion of one of the coronary arteries. The occlusion can stem from atherosclerosis, thrombosis, platelet aggregation, or coronary artery stenosis or spasm. Predisposing risk factors include:
- Aging
- Diabetes mellitus
- Elevated serum triglyceride, low-density lipoprotein, and cholesterol levels, and decreased serum high-density lipoprotein levels
- Excessive intake of saturated fats, carbohydrates, or salt
- Hypertension
- Obesity
- Positive family history of coronary artery disease
- Sedentary lifestyle
- Smoking
- Stress or a type a personality (aggressive, competitive attitude, addiction to work, chronic impatience).
- In addition, use of such drugs as amphetamines or cocaine can cause a Myocardial infarction (MI).
Complications for Myocardial Infarction (MI)
Cardiac complications of Acute Myocardial infarction (MI)
- Arrhythmias.
- Cardiogenic shock.
- Heart failure.
- Pulmonary edema
- Pericarditis.
- Rupture of the atrial or
- Ventricular septum,
- Ventricular wall, or valves;
- Ventricular aneurysms
- Cerebral or pulmonary emboli.
- Dressler's syndrome can occur days to weeks after an Myocardial infarction (MI) and cause residual pain, malaise, and fever.
Typically, elderly patients are more prone to complications and death. Psychological problems can also occur, either from the patient's fear of another Myocardial infarction (MI) or from an organic brain disorder caused by tissue hypoxia. Occasionally, a patient may have a personality change.
Nursing Assessment nursing care plans for Myocardial infarction (MI)
PATIENT HISTORY
Symptomatology is very important in diagnosing Myocardial infarction (MI). Ask about chest, jaw, arm, and epigastric pain. Remember that not all people have the “typical” chest pain; evaluate the whole clinical picture because some people may experience no pain at all. Ask about shortness of breath, racing heart rate, diaphoresis, clammy skin, dizziness, nausea, and vomiting. Note that sudden death and full cardiac arrest may be the first indication of Myocardial infarction (MI).
Patients with coronary artery disease may report increasing anginal frequency, severity, or duration (especially when not precipitated by exertion, a heavy meal, or cold and wind). The patient may also report a feeling of impending doom, fatigue, nausea, vomiting, and shortness of breath. Sudden death, however, may be the first and only indication of an Myocardial infarction (MI).
PHYSICAL EXAMINATION.
- Inspection may reveal an extremely anxious and restless patient with dyspnea and diaphoresis.
- If right-sided heart failure is present, you may note jugular vein distention.
- anterior Myocardial infarction (MI), patients exhibit sympathetic nervous system hyperactivity, such as tachycardia and hypertension.
- Patients with an inferior Myocardial infarction (MI) exhibit parasympathetic nervous system hyperactivity, such as bradycardia and hypotension.
- In patients who develop ventricular dysfunction, auscultation may disclose an S4, an S3, paradoxical splitting of S2, and decreased heart sounds.
- A systolic murmur of mitral insufficiency may be heard with papillary muscle dysfunction secondary to infarction.
- A pericardial friction rub may also be heard, especially in patients who have a transmural Myocardial infarction (MI) or have developed pericarditis.
- Fever is unusual at the onset of MI, but a low-grade fever may develop during the next few days.
Diagnostic tests for Myocardial infarction (MI)
Persistent chest pain, ST-segment changes on ECG, and elevated levels of total creatine kinase (CK) and the CK-MB isoenzyme over a 72-hour period usually confirm Myocardial infarction (MI). Cardiac troponins are useful in differentiating MI from skeletal muscle injury, or when CK-MB measurements are low and a small MI has actually occurred.
Diagnostic Highlights
- Electrocardiogram
- Creatine kinase isoenzyme (MB-CK)
- Cardiac troponin I (cTnI)
- cardiac troponin T (cTnT)
Elevated homocysteine and C-reactive protein levels have been found incidentally in patients with Myocardial infarction (MI) and may indicate a newer risk factor. The practical value of these tests remains unknown. Folic acid supplementation is used as treatment for elevated homocysteine levels
Nursing diagnosis Nursing Care Plan For Myocardial Infarction (MI).
Primary Nursing Diagnosis: Altered tissue perfusion (myocardial) related to narrowing of the coronary arteryies associated with atherosclerosis, spasm, or thrombosis
Common nursing diagnosis found on Myocardial infarction (MI).
- Activity intolerance
- Acute pain
- Anxiety
- Decreased cardiac output
- Excess fluid volume
- Fatigue
- Imbalanced nutrition: Less than body requirements
- Ineffective coping
- Ineffective denial
- Ineffective sexuality patterns
- Ineffective tissue perfusion: Cardiopulmonary
Infarction (MI). Click Here
Other resource for Myocardial Infarction care
ECG in Acute Myocardial Infarction and Unstable Angina!
Complications of Myocardial Infarction!
Management of Acute Coronary Syndromes!
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