ACUTE MYOCARDIAL INFARCTION （AMI）.pp Definitionpp Prevalence pp Cause pp Symptoms pp and signspp Auxiliary examinations pp。Contents ppDiagnosis ppThe differential diagnosisppcomplications ppTherapy pp。.Definition Death or necrosis of myocardial cells.Definition lFrom an anatomic or morphologic standpoint l - transmural l -non transmural.Definition From ECG finding -ST elevation STEMI -non-ST elevation NSTEMI.Prevalence The World Health Organization estimated in 2019, that 12.2% of worldwide deaths were from ischemic heart disease.Leading cause of death in high- or middle-income countries. Second only to lower respiratory infections in lower-income countries. .Worldwide, more than 3 million people have STEMIs and 4 million have NSTEMIs a year.STEMIs occur about twice as often in men as women.In general，MI can occur at any age，but its incident rises with age.Approximately 50% of all MIs in the US occur in people younger than 65 years of age.Mortality The mortality is 50% in 24 hours.Cause Coronary atherosclerosis Formation of thrombus Obstruction of blood flow Muscle death in cardiac muscle .Plaque rupture Plaque rupture adventitialipid coreCholesterol nuclearthrombosis .Ruptured plaques .Risk factors AgeHyperlipidemiaDiabetes mellitus Hypertension Smoking Male gender Family history of atherosclerotic arterial disease (inheritance).Inducing factors Early hours of the morning Overeating Heavy physical activity AgitationRapid rise of blood pressure Defecating hardly Shock DehydrationSurgery Severe arrhythmia .Symptoms Prodromal symptoms:Pain of infarction Associated symptomsPainless infarction sudden death and Early arrhythmias .Prodromal symptomsOccur at rest or with less activity than usual.Approximately one third have had symptoms from 1 to 4 weeks before.Pain of infarction At rest In the early morning Similar to angina in location and radiation but more severe.Nitroglycerin has little effect ,even opioid may not relieve the pain . .Associated symptomscold sweat weak Light-headednessapprehensive syncope dyspneaorthopneacough wheezingnausea and vomiting abdominal bloating.Painless infarction It is estimated that at least 20% of acute MIs are painless or atypical . Elderly patients and patients with diabetes are particularly prone painless or atypical MI.sudden death and Early arrhythmias About 50% occur before the patients arrive at the hospitals,with death presumably caused by ventricular fibrillation . .Signs general Chest Heart Extremities .Signs General Anxious Sweating profusely bradycardia or tachycardiaLow cardiac output Arrhythmia High or low blood pressure Respiratory distress Fever .Signs Chest Rale(pulmonary edema ) Killip classification Class I =absence of Rales Class II=less 50% of the lung fields Class III=over 50% of the lung fields Class IV=cardiogenic shock(rales,hypotension , and signs of hypoperfusion ).Signs Heart Abnormally located ventricular impulse dyskinetic infractedJugular venous distension right atrial hypertension Soft heart sounds left ventricular dysfunction . HeartS 4 atrial gallops S3 ventricular gallops cardiac insufficiency mitral regurgitation murmur papillary muscle dysfunction rarely rupture Pericardial friction rubs .Signs Extremities Edema Cyanosis and cold temperature low output Peripheral pulses .Auxiliary examinations ElectrocadiographyLaboratory findings Echocardiography.ElectrocadiogramECG changes:ST segment elevation Q wave development T wave inversion.ST segment elevation . .Q wave development .T wave inversion.Location Inferior wall aVF Anterior wall V16 Anteroseptal wall V1-3 Apical or lateral wall V46 Posterior wall-V7-9 Right-sided -V4R-V5R.Laboratory findings Marker Time to appearance Duration of elevation 6hr12hrSpecificity Troponin I 2-6hr 5-10d75%90%-100%98%Troponin T2-6hr 5-14d80%95%-100%95%CK-MB3-6hr 2-4d65%95%95%myoglobin1-2hr 1d85%90%80%.Echocardiography. .WHO Definition Of MIDiagnosis .Chest pain History 、examination and ECG Acute coronary syndrome （ACS）ST segment elevation Non-ST segment elevation NSTEMIUANo TnI(TnT)STEMITnI(TnT)TnI(TnT).The differential diagnosis ppAngina ppAcute pericarditis ppAcute pulmonary embolism ppAcute abdominal pain ppAortic dissection .Complications ppDysfunction or rupture of papillary muscle ppRupture of the heart ppEmbolism ppCardiac aneurysmppPostinfarction syndrome .Therapy General treament measures Control of cardiac pain Recanalization therapy Control of arrhythmias Control of shock Control of heart failureOther therapiesTherapies of complications .Prevention A aspirin anti A aspirin antianginal therapy anginal therapy B beta-blocker blood pressure control B beta-blocker blood pressure control C cholesterol lowing cigarettes quiting C cholesterol lowing cigarettes quiting D diet control diabetes treatment D diet control diabetes treatment E education exercise E education exercise . .