INTRODUCTION
Heart attack also called a myocardial infarction. MI occurs when the flow of blood to the heart is blocked; the interrupted blood flow can damage or destroy part of the heart muscle. A heart attack differ from a condition in which heart suddenly stops (sudden cardiac arrest) which occurs when an electrical disturbance disrupts blood to stop flowing to the rest of body. A heart attack may cause cardiac arrest but it is not the only cause.
DEFINITION
It is defined as death of a segment of heart muscle, which follows interruption of its blood supply.
When in myocardium layer of heart, blood supply coronary artery branch is interrupted or stopped then O, supply also stop in any area in heart, after absence of O, necrosis happens there. It is called myocardial infarction or myocardial death.
CAUSES
(a) Acute coronary thrombosis:
About 90% cases of MI are due to severe coronary heart disease
(B) Arteriosclerosis:
Hardening of arteries.
(c) Other factors:
- Sudden constriction/vasospasm of coronary arteries
- Excessive exercise
- CA (Coronary Artery) embolism
- Infectious disease
- Hypoxia
- Smoking
- Increase fatty diet intake
CLINICAL MANIFESTATIONS
- Severe chest pain of anterior chest, neck, shoulder or mandible occurring during rest or exertion.
- Diaphoresis (excessive sweating)
- Hypertension
- Tachycardia
- Disorientation
- Palpitation
- Dyspnoea
- Nausea, vomiting
- Anxiety
- Feeling of indigestion
- S.O.B. (Shortness of Breath).
- Cold calm skin
CHARACTERISTICS OF M.I. CHEST PAIN
- Severity: More than angina pectoris.
- Duration: More than 15 minutes and not relieved by nitroglycerin.
- Radiation: Pain radiated to nose, jaw, shoulder forearm, 4th, 5th fingers.
SITE OF MI
- Most common anterior wall of left ventricle due to thrombus in left arm.
- Posterior wall of heart due to blockage in right coronary artery.
- Inferior wall of heart due to right coronary artery blockage.
DIAGNOSTIC EVALUATIONS
- By ECG (S T El evation)
- Echocardiography
- Coronary angiography
- PET (Positron Emission Tomography)
-
Lab findings:
- Elevated CK= Creatinine kinase within 3-6 hrs.
- ↑ es serum AST =Aspirate amino transferase
- ↑ LDH= Lactate dehydrogenase in 12-24 hrs.
- ESR ↑es Erythrocytes sedimentation rate↑
- MRI (Magnetic Resonance Imaging)
COMPLICATIONS
- Pulmonary embolism
- Heart failure
- Dysrhythmia.
- Pericarditis, Myocarditis, Endocarditis
- Shock
MANAGEMENT
Medical Management
- Pain management by morphine sulphate 5-10 mg Sc.
-
Vasodilators:
- Nitrates
- B-Blockers
- Calcium channel blockers
- Anxiolytics drugs, e.g., Benzo-diazepines.
- Anticoagulant, e.g., Heparin
- Thrombolytic, e.g.. Streptokinase, urokinase.
- Antidysrhythmic, e.g.. Lignocaine, xylocaine.
Surgical Management
CABG Coronary artery bypass grafting.
PTCA Percutaneous transluminal coronary angioplasty.
Dietary Management
- Low fat/cholesterol diet
- Low sodium diet
- Avoid caffeine intake
- Avoid alcohol use.
Nursing Management
- Assess the pain, location, severity, intensity, onset and radiation, frequency
- Administer morphine sulphate to control pain
- We should provide quiet and calm environment and comfort measures to reducing a and cardiac strain.
- Relieve anxiety and give reassurance
- Provide teaching related to activities that would restrict blood flow, e.g., diet, exp to cold, use of caffeine and nicotine.
- Monitor heart rate and rhythm.
- Administer supplemental O₂ as needed.
- Provide medications as directed, e.g., diuretics, vasodilators, ACE inhibitors, digitalis, ẞ-blocker, anticoagulants.
Nursing Diagnosis
- Acute pain related to myocardial ischemia and necrosis.
- Anxiety related to fear of death and chest pain.
- Activity intolerance related to imbalanced between myocardial O₂ supply and demand.
- Risk for decreased cardiac output related to reduced preload, dysrrhythmias, decrease contracture ability of cardiac muscles.
- Ineffective tissue perfusion related to infarction, obstruction in blood flow.
- Deficient knowledge related to disease condition, treatments, self-care.