ACUTE MYOCARDIAL INFARCTION

• Myocardial infarction is also known as a heart attack.
• Myocardial infarction is caused by complete blockage of the coronary artery, interrupting the blood and oxygen flow to the heart resulting in injury, ischemia, or death of the heart muscle.
• The ECG changes caused by MI are T-wave inversion, ST-elevation, and abnormal Q wave
• The symptoms of MI include chest pain, shortness of breath, indigestion, nausea, anxiety, cool, pale, moist skin, increased HR and RR.
• Non-modifiable risk factors for MI are age, gender, genetic factors, race and ethnicity.
• Modifiable risk factors for MI are obesity, high BP, DM, smoking, physical inactivity, and high blood cholesterol
• Lab and diagnostic tests used to diagnose AMI are: 12-lead ECG, cardiac biomarkers (troponin I, troponin T, CK-MB, myoglobin), echocardiogram
• MI can be classified as NSTEMI (non-ST segment elevation MI) and STEMI
• Treatment options for AMI: oxygen therapy, aspirin, morphine, nitroglycerin, beta-blocker, ACE inhibitor, heparin, statins
• Percutaneous coronary intervention is a procedure used to open the occluded coronary artery and promote reperfusion to the area that has been deprived of oxygen
• PCI is performed should be less than 60 minutes and is called door-to-balloon time
• Thrombolytic (fibrinolytic) therapy is initiated when primary PCI is not available or the transport time to a PCI-capable hospital is too long
• The purpose of thrombolytics (fibrinolytics) is to dissolve (i.e., lyse) the thrombus in a coronary artery (thrombolysis), allowing blood to flow through the coronary artery again (reperfusion), minimizing the size of the infarction and preserving ventricular function.
• Medications of choice for thrombolytic therapy are alteplase, reteplase, tenecteplase
• They should be given within 30 minutes of presentation to the hospital and is referred as the door-to-needle time
• In percutaneous transluminal coronary angioplasty (PTCA), a balloon- tipped catheter is used to open blocked coronary vessels and resolve ischemia.
• The purpose of PTCA is to improve blood flow within a coronary artery by compressing the atheroma.
• After PTCA, the area that has been treated may close off partially or completely—a process called restenosis
• A stent is a metal mesh that provides structural support to a vessel at risk of acute closure.
• Complications that can occur during a PCI procedure include coronary artery dissection, perforation, abrupt closure, or vasospasm.
• Coronary artery bypass graft (CABG) is a surgical procedure in which a blood vessel is grafted to an occluded coronary artery so that blood can flow beyond the occlusion;
• A vein commonly used for CABG is the greater saphenous vein, followed by the lesser saphenous vein
• Cardiopulmonary bypass is a procedure mechanically circulates and oxygenates blood for the body while bypassing the heart and lungs
• The heart is stopped by the injection of a potassium-rich cardioplegia solution into the coronary arteries. The patient receives heparin to prevent clotting and thrombus formation in the bypass circuit when blood comes in contact with the surfaces of the tubing. At the end of the procedure when the patient is disconnected from the bypass machine, protamine sulfate is given to reverse the effects of heparin.
• CABG may result in complications such as hemorrhage, dysrhythmias, and MI