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Journal Reading. Myocardial infarction in young people Cardiol J 2009; 16, 4: 307–311 Cardiol J 2008; 15: 21–25 Presented by R 王郁菁 2011-06-16 at ER conference room. Introduction. The borderline differentiating younger from older patients is the age of 40 .
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JournalReading Myocardial infarction in young people Cardiol J 2009; 16, 4: 307–311 Cardiol J 2008; 15: 21–25 Presented by R 王郁菁 2011-06-16 at ER conference room
Introduction • The borderline differentiating younger from older patients is the age of 40. • MI in patients below the age of 40 constitute about 10% of all cases. • The majority of sufferers are men • Increasing prevalence among women • 1 in 4 patients with MI <45 years are women Cardiol J 2009; 16,4: 307-311
Causes • Main cause: coronary atherosclerosis • About 80% of cases • Usually one vessel disease • Significant lesions in coronary arteries may be present as early as age 25-30 • >40, the first symptoms of exercise-induced ischemia are not uncommon • Environmental influence on genotype may promote the development of coronary artery disease in young age Cardiol J 2009; 16,4: 307-311
Atherosclerosis • Smoking • Religa et al • 100 women with first MI: 45% were smoker • <45 y/o: 95% were smoker • Impairs endothelium derived vasodilation mechanisms and vasospasm in coronary arteries • Dyslipidemia: • 29% • Premature coronary artery disease is most common in patients with familial hypercholesterolemia, less often in familial mixed dyslipidemia • High TG, high total cholesterol (LDL), low HDL Cardiol J 2009; 16,4: 307-311
Atherosclerosis • Premature ischemic heart disease in first-degree relatives • an independent risk factor • Apolipoprotein E (Allel E4): an important risk factor for atherosclerosis and IHD • Arterial hypertension: 5% • Obesity • Doubles the risk of MI in men • Increases the risk in women by 2.5 times • Excessive accumulation of TG impairs the function of cardiomyocytes, liver and pancreas Cardiol J 2009; 16,4: 307-311
Causes without coronary artery stenosis • Coronary artery embolism • Thrombosis • Anomaly • Vessel inflammation or spasm Cardiol J 2009; 16,4: 307-311
Coagulation disorders • 5% of all cases • Imbalance between coagulation and fibrinolysis increase risk of thrombus forming Cardiol J 2009; 16,4: 307-311
Anomaly • Rare cases • Myocardial bridge • Coronary arteries tunnels through the myocardium • 15-85% is found during autopsies • 0.5-2.5% is found from angiography Cardiol J 2009; 16,4: 307-311
Drug abuse • Cocaine • Amphetamine • Increasing numbers of MI • MI after cocaine abuse was first reported in 1982. Cardiol J 2009; 16,4: 307-311
Cocaine or Amphetamine abuse • Causes heart rate and systolic blood pressure increase with artery spasm • Reduced coronary flow imbalance between oxygen consumption and supply • Increase in thrombocytes aggregation • Blocking of sodium channels and the presynaptic part of neuron • Excessive release of neurotransmitters like norepinephrine and dopamine • Transient impairment of blood flow Cardiol J 2009; 16,4: 307-311
Direct toxin lesion of myocardium, resulting in focal necrosis • Marijuana smoker • Overdosing on medicines: Rifampicine • Toxic influence on endothelium may be the cause of drug-induced acute coronary syndromes Cardiol J 2009; 16,4: 307-311
Uric acid • Another study: 2000.01-2005.12 • 80 patients were less than 35 years old and were diagnosed as AMI Cardiol J 2008; 15: 21-25
Hyperuricemia: >7.0mg/dl • An independent factor of mortality • Underlying mechanisms remain unclear • Hypothesis • Promotes vascular smooth muscle proliferation and upregulates the expression of platelet-derived growth factor and monocyte chemoattractant protein-1 • May induce endothelial dysfunction by decreasing the production of nitric oxide in the vascular endothelial cells Cardiol J 2008; 15: 21-25
Prognosis • If patients have DM, that may have multi-vessel lesion • Young patients usually have no concomitant disorders • After MI in young patients • Higher LVEF • Lower levels of pro-BNP than older groups • Favorable clinical course • Increased risk of recurrent coronary events concerns only 5% • Problem of sudden death risk remains Cardiol J 2009; 16,4: 307-311