Original Editors - Jessica King & Melissa Tuemler from Bellarmine University's Pathophysiology of Complex Patient Problems project. Show
Top Contributors - Jessica King, Melissa Tuemler, Lucinda hampton, Vidya Acharya, Kim Jackson, Admin, Elaine Lonnemann, WikiSysop, Wendy Walker, Evan Thomas, Venus Pagare and Karen Wilson Introduction[edit | edit source]Myocardial infarction (MI) (colloquially known as a heart attack) results from interruption of myocardial blood flow and resultant ischaemia and is a leading cause of death worldwide[1]. MI is mainly due to underlying coronary artery disease. When the coronary artery is occluded, the myocardium is deprived of oxygen. Prolonged deprivation of oxygen supply to the myocardium can lead to myocardial cell death and necrosis. Image 1:Cardiac MRI flow. Etiology[edit | edit source]Risk factors
Epidemiology[edit | edit source]
Characteristics/Clinical Presentation[edit | edit source]Myocardial ischemia can present as
Signs and symptoms vary based on gender.
Evaluation/Laboratory markers[edit | edit source]The mainstay of diagnosis revolves around: Cardiac biomarkers; ECG findings; and clinical features.
Image 5: Normal ECG wavelength Imaging is used to assess myocardial perfusion, myocardial viability, myocardial thickness, thickening and motion, and the effect of myocyte loss on the kinetics of para-magnetic or radio-opaque contrast agents indicating myocardial fibrosis or scars.
Pathology[edit | edit source]Coronary artery disease with rupture of an atherosclerotic plaque resulting in occlusion (local thrombosis/dissection) is the major cause of myocardial infarctions. Other causes include:
Treatment[edit | edit source]The diagnosis and management of patients with MI is best done with an interprofessional team. In most hospitals, there are cardiology teams that are dedicated to the management of these patients. For patients who present with chest pain, the key to the management of MI is time to treatment.
Long term management There is no cure for ischemic heart disease, and all treatments are symptom-oriented.
Prognosis[edit | edit source]Acute MI carries a mortality rate of 5-30%; the majority of deaths occur prior to arrival to the hospital.
Factors that worsen prognosis include:
Physical Therapy Management[edit | edit source]Cardiac Rehab is beneficial to patients of all ages who have had a heart attack, CAD, angina, or CHF. Other individuals who may gain benefits from this include post-surgical CABG, percutaneous intervention (PCI), or coronary angioplasty patients. Indications for Cardiac Rehab[edit | edit source]
According to the American Heart Association, the benefits of cardiac rehab include:
Prevention[edit | edit source]Evidence based interventions for secondary prevention include the use of aspirin, beta-blockers, angiotensin converting enzyme inhibitors; lipid lowering drugs and other anti- hypertensives, as well as modifying lifestyle related risk behaviours. Physical exercise Although the role of exercise alone in reducing cardiovascular outcomes is not clear, systematic reviews of RCTs have found that cardiac rehabilitation which includes physical exercise improves coronary risk factors and reduces the risk of major cardiac events in people after MI.[3] Dietary Modification RCTs have found that advising people with MI to eat more fish, fruit and vegetables, bread, pasta, potatoes, olive oil and margarine may result in a substantial survival advantage[3]. Stopping smoking Apart from these pharmacological measures for secondary prevention, evidence is available that lifestyle measures such as stopping smoking, encouraging a healthy diet and exercise can also significantly contribute to reduction in cardiovascular mortality in people with established CVD. Evidence from epidemiological studies indicates that people with coronary heart disease who stop smoking rapidly reduce their risk of recurrent coronary events or death. In the case of stroke survivors, observational studies have shown that the excess risk of stroke among former smokers largely disappeared 2-4 years after smoking cessation[3]. Medications[edit | edit source]Following an MI, patients will most likely be prescribed some form of medication for the rest of their lives[9].
Resources[edit | edit source]
References[edit | edit source]
Which assessment may indicate a myocardial infarction?ECG remains the first line test for myocardial infarction together with the use of biomarkers in the acute setting. Catheter based coronary angiography is used for the diagnosis and treatment of acute coronary syndrome.
What is the best method to determine whether the client is experiencing a myocardial infarction or angina?Your doctor may perform an electrocardiogram (ECG), a stress test without imaging or blood tests to help diagnose your condition. Additionally, chest x-ray, chest CT, coronary CT angiography, cardiac MRI, coronary angiography, echocardiogram or stress test with imaging may be performed.
Which of the following is the most common symptom of myocardial infarction MI )?The most common symptom of myocardial ischemia is angina (also called angina pectoris). This is chest pain (similar to indigestion or heartburn) that feels like: Chest discomfort.
Which of the following are indicators of myocardial injury?Symptoms of acute myocardial infarction include chest pain or discomfort with or without dyspnea, nausea, and/or diaphoresis. Women and patients with diabetes are more likely to present with atypical symptoms, and 20% of acute MI are silent. Diagnosis is by ECG and cardiac markers.
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