1、Myocardial infarction 心肌梗死 Myocardial infarction(MI or AMI for acute myocardial infarction),also known as a heart attack心脏病发作心脏病发作,occurs when the blood supply to part of the heart is interrupted,resulting ischemia and oxygen shortage,if left untreated for a sufficient period,can cause damage and/or
2、 myocardium infarction.Angina心绞痛心绞痛as a result of ischemia causes reversible cellular injury,and infarction is the result of sustained ischemia,causing irreversible cellular death.Healing process愈合过程Within 24 hours:The bodys response to cell death is the inflammation process.Leukocytes白细胞 infiltrate
3、 the area.Enzymes 酶are released from the death cardiac cells and are important diagnostic indicators.Healing process愈合过程The second or third day:The proteolytic enzymes蛋白水解酶蛋白水解酶of neutrophils and macrophages巨噬细胞巨噬细胞remove all necrotic坏死坏死 tissue and the necrotic muscle wall is thin.Development of co
4、llateral circulation improve the area of poor perfusion and may limit the zones of injury and infarction.1.Once infarction takes places,catecholamine-mediated儿茶酚胺介导儿茶酚胺介导 lipolysis脂解脂解(作用作用)and glycogenolysis糖原分解糖原分解 occur.For this reason,serum glucose levels are frequently elevated after MI and may
5、 be the reason for a pseudodiabetic state假性糖尿假性糖尿病病.Healing process愈合过程Within 4 to 10 days:The necrotic zone is identifiable by ECG changes,at this point,the phagocytes(neutriphils and monocytes 中性粒细胞和单核细胞中性粒细胞和单核细胞)have clear the necrotic debirs坏死的碎片坏死的碎片from the injury area and the collagen matrix
6、 胶原基质胶原基质that will eventually form the scar瘢痕瘢痕is laid down.At 10 to 14 day:The beginning of scar tissue 疤痕组织疤痕组织 is weak.The myocardium is considered to be especially vulnerable to increased stress because of the unstable state of the healing heart wall.6 weeks after MI:Scar tissue has replaced nec
7、rotic tissue,at this time,the injured area is said to be healed.Clinical manifestation 临床表现Pain Severe,immobilizing chest pain not relieved by rest or nitrate administration is the hallmark of an MI.it is often described as a sensation of tightness,pressure压榨压榨,or squeezing紧缩紧缩.Common locations are
8、substernal胸骨下胸骨下and retrosternal胸骨后胸骨后.Pain radiates most often to the left arm,but may also radiate to the lower jaw下颌，下颌，neck,right arm,back,and epigastrium腹上部腹上部,where it may mimic heartburn.Pain are commonly occurs in the early morning hours.It usually lasts for 20 minutes or more.Clinical manif
9、estation Nausea and vomiting Nausea and vomiting can result from reflex stimulation of the vomiting center by the sever pain and can also result from vasovagal reflex血管迷走性血管迷走性反射反射from the area of the infarcted myocardium.Sympathetic stimulation Diaphoresis发汗发汗,weakness,light-headedness,and palpitat
10、ions心悸心悸.These symptoms are likely induced by a massive surge of catecholamines儿茶酚氨儿茶酚氨from the sympathetic nervous system which occurs in response to pain and the hemodynamic abnormalities血流动力学的异常血流动力学的异常that result from cardiac dysfunction心功能不全心功能不全.Clinical manifestation Fever The temperature may
11、 increase within the first 24 hour up to 38 to 39.the temperature elevation may lasts for as long as 1 week.Cardiovascular manifestations The BP and pulse rate may be elevated initially,later BP may drop because of decreased CO.Urine may be decreased.Crackles湿啰音湿啰音may be noted in the lungs,persistin
12、g for several hours to days Hepatic engorgement 肝怒张肝怒张and peripheral edema外外周水肿周水肿may indicate covert cardiac failure.Jugular veins 颈静脉颈静脉 may distended and may have obvious pulsations搏动搏动,indicating early right ventricular dysfunction and pulmonary congestion.Complication Dysrhythmias 心律失常心律失常:are
13、the most common complication,present in 80%of MI patient.The intrinsic rhythm of the heartburn is disrupted,causing either a fast HR(tachycardia心动过速心动过速),a slow HR(bradycardia心动过缓心动过缓),or an irregular beat.Complete heart block心脏传导阻滞心脏传导阻滞is seen in massive infarction.Ventricular fibrillation室颤室颤,a c
14、ommon cause of sudden death,is a lethal dysrhythmia that most often occurs within the first 4 hours after the onset of pain.Premature ventricular contractions室性早搏室性早搏(PVCs)may precede ventricular tachycardia室性心动过速室性心动过速and fibrillation室颤室颤.Ventricular dysrhythmia needs immediate treatment.Complicati
15、on Congestive heart failure Cardiogenic shock Papillary muscle dysfunction乳头肌乳头肌功能障碍功能障碍 Ventricular aneurysm室壁瘤室壁瘤 Pericarditis心包炎心包炎 Dressler syndrome德雷斯勒综合征，心德雷斯勒综合征，心肌梗死后综合征肌梗死后综合征 Pulmonary embolism肺栓塞肺栓塞Diagnostic studies辅助检查 Three noninvasive diagnostic parameters are used to determine whethe
16、r a person has sustained an acute MI:The patients history of pain,risk factors and health history.12-lead ECG consistent with acute MI(inverted倒置倒置T waves,ST-T waves elevations of greater than 1 mm or more in two contiguous leads,abnormal Q wave)Measurement of serial myocardial serum enzymesOther me
17、asures includes:Chest X-rayCBC,thyroid profileNuclear imaging studiesEndocardiogramDiagnostic studies ECG findingsECG are approximately 80%specific for diagnosing an acute MI and represent a leading diagnostic criterion.Diagnostic studies辅助检查Cardiac enzymes:An important diagnostic criterion for acut
18、e MI is laboratory assessment of serial cardiac serum enzymes.Creatine kinase肌酸激酶肌酸激酶(CK):CK levels begin to rise approximately 6 hours after an acute MI and return to normal within 2 to 3 days.Lactic dehydrogenase乳酸脱氢酶乳酸脱氢酶(LDH)Aspartate aminotransferase谷草转氨酶谷草转氨酶(AST)Therapeutic management治疗方案IV t
19、herapy Initial management of MI is best accomplished in a cardiac care unit(CCU),where constant monitoring is available.An IV route is established to provide an accessible means for emergency drug therapy.Morphine 吗啡吗啡sulfate may be given IV 2-4 mg/hr as needed for relief of pain(or meperidine 度冷丁度冷
20、丁if patient is allergic to morphine)A continuous IV infusion of lidocaine 利多卡因利多卡因may be given,prophylactically to prevent ventricular fibrillation室颤室颤.Therapeutic management治疗方案Oxygen therapyContinual ECG monitoring to deter dysrhythmiasVital signs are taken frequently during the first few hours af
21、ter admission and are monitored 1-4 hr thereafter.Bed rest and limitation activity are usual initially,with a gradual increase in activity.Recording intake and outputA pulmonary artery(PA)catheter肺动脉导管肺动脉导管and intraarterial line 动脉内置管动脉内置管may be used to accurately monitor intracardiac,pulmonary arte
22、ry,and systolic arterial pressures in complicated MI so that the most effective mode of treatment in the acute phase can be determined.Therapeutic management Thrombolytic therapy溶栓疗法溶栓疗法It is now known that 80%to 90%of all acute MI are secondary to thrombus formation.Thrombolytic therapy is the stan
23、dard of practice in the treatment of acute MI.Myocardial cells do no die instantly.It takes approximately 4 to 6 hours for entire thickness of the muscle to become necrosed and this is known as transmural infarction 跨壁梗死跨壁梗死.Treatment of acute MI is geared to quickly dissolving thrombus in the coron
24、ary artery and reperfusing the myocardium before cellular death occurs.To be of most benefit,thrombolytics must be given as soon as possible,perferably within the first 6 hours after the onset of pain.Therapeutic management Thrombolytic therapy溶栓疗法Thrombolytic agents used to treat myocardial infarct
25、ion are:streptokinase(链激酶链激酶),urokinase(尿激酶尿激酶),tissue plasminogen activator(t-PA)(组组织纤维蛋白溶酶原激活剂织纤维蛋白溶酶原激活剂).Indications of thrombolytic therapy:Chest pain typical of acute MI less than or equal to 6 hr in duration(some centers extend the time limit to 12 hr).12-lead ECG findings consistent with acu
26、te MI.Thrombolytic therapy溶栓疗法溶栓疗法Contraindications of thrombolytic therapy:Absolute contraindications禁忌禁忌:History of hemorrhagic strokeUncontrolled hypertension(SBP200,DBP120)Recent surgery or trauma(within 2 wk)Active internal bleedingKnown bleeding disorderSuspected aortic dissention主动脉剥离主动脉剥离Rel
27、ative contraindications:History of stroke Acute,poor Uncontrolled hypertension(BP180/110)Malignancy妊娠妊娠Acute pericarditis急性心包炎急性心包炎Pregnancy妊娠妊娠Active peptic ulcer活动性消化性溃疡活动性消化性溃疡Diabetic hemorrhagic retinopathy 糖尿病性视网膜病变糖尿病性视网膜病变Artial fibrillation房颤房颤nursing care for thrombolytic therapyECG,vital
28、signs,heart and lung assessments are completed as often as every 5 minutes to evaluate the patients response to therapy.When reperfusion occurs,several clinical markers may occurs,nurses should monitor them,those signs of reperfusion includes chest pain resolution,return of ST segment to baseline on
29、 the ECG,the presence of reperfusion dysrhythmias再灌注性心律失常再灌注性心律失常(premature ventricular contractions室性早搏室性早搏,ventricular tachycardia室性心动过速室性心动过速,ventricular fibrillation心室颤动心室颤动),rapid rise of the CK enzymes within 3 hrs of therapy,peaking within 12 hrs.nursing care for thrombolytic therapyAnother m
30、ajor concern with therapy is reocclusion动脉重新堵塞动脉重新堵塞of the artery,because of this possibility,an IV bolus is given,followed by heparin drip to maintain the patients Partial Thromboplasm Time(PPT)部分凝血酶原时间部分凝血酶原时间at one to two times normal,this prevent another clot form forming in the coronary artery.
31、The major complication with thrombolytic therapy is bleeding.The nurses must pay particular attention to signs and symptoms of bleeding such as gingival bleeding牙龈牙龈,drop in BP,an increasing in HR,hematuria 血尿血尿,a sudden change in patients level of consciousness and oozing渗出渗出of blood from IV or cat
32、heter site.Therapeutic management 9.Percutaneous Coronary Intervention(PCI)冠状动脉介入治疗冠状动脉介入治疗BalloonStentLaserRotablatorPercutaneous transluminal coronary angioplasty(PTCA)经皮腔内冠状动脉成形术经皮腔内冠状动脉成形术.Percutaneous transluminal coronary angioplasy(PTCA)经皮腔内冠状动脉成形术经皮腔内冠状动脉成形术.Percutaneous transluminal coronar
33、y angioplasy(PTCA)经皮腔内冠状动脉成形术经皮腔内冠状动脉成形术.PCI Complication 冠状动脉介入治疗的并发症冠状动脉介入治疗的并发症 Acute abrupt closure of coronary vessels serious arrhythmias:VT室速，室速，VF室颤。室颤。Cardiac tamponade心心包填塞包填塞 Vascular complication Low blood pressure Stroke Hemorrhage Renal failure Heart attack DeathCoronary artery bypass
34、surgery(CABG)冠状动脉搭桥手术冠状动脉搭桥手术Coronary artery bypass surgery(CABG)冠状动脉搭桥手术冠状动脉搭桥手术Pharmacologic management药物管理 IV nitroglycerin硝酸甘油硝酸甘油 IV Morphine 吗啡吗啡 Morphine can reduce anxiety,decrease cardiac work load,reduce contractility,lower BP and slow the HR.Antidysrhythmic drugs抗心律失常药物抗心律失常药物 Dystrhythmi
35、a are the most common complications after MI.-Blockers Calcium channel blockers Angiotensin-converting enzyme inhibitors Stool softeners Nutrition management Diet is restricted in saturated fats饱和饱和脂肪和脂肪和 and cholesterol胆固醇胆固醇and is sometimes low in sodium to prevent fluid retention.The patient may
36、have a clear liquid diet the first day when there may still be nausea.Nursing diagnosis and intervention Acute pain related to lactic acid production from myocardial ischemia and altered myocardial oxygen supply.Administer oxygen through nasal cannula to increase oxygenation of myocardial tissue and
37、 prevent further tissue ischemia.Administer morphine sulfate IV as needed to decrease anxiety,elevated pain and decrease cardiac work load.1.Monitor vital signs q1-2hr to provide on-going assessment of patients response to treatment.Nursing diagnosis and intervention Altered cardiac tissue perfusion
38、 related to myocardial damage,ineffective CO and potential pulmonary congestionProvide long,uninterrupted rest period to promote cardiac rest and healing.Minimize cardiac workload during healing.Explain necessity of bed rest and decreased activity to promote patient cooperation.Allow rest periods be
39、tween concentrated nursing care time to reduce fatigue and oxygen requirements of myocardium.1.Asses urine output to determine adequacy of renal blood flow.Nursing diagnosis and intervention Impaired gas exchange related to ineffective breathing pattern and decreased systemic tissue perfusion second
40、ary to decreased CO.Elevated head of bed to allow gravity to lower the diaghragm and decrease the work of breathing and reduce venous return.Hold morphine and notify physician if respiratory rate less than 10-12/min because morphine is a respiratory depressant.1.Maintain oxygen therapy as order.Nurs
41、ing diagnosis and intervention Activity intolerance related to fatigue secondary to decreased CO and poor lung and tissue perfusionMeet patients need quickly and efficiently to conserve energy and prevent anxiety.Encourage patient to maintain bed rest.Monitor BP,pulse,respiration and color to monito
42、r patients response to activity and to adjust as necessary.1.Administer oxygen during activity to increases O2 availability for cardiac and other organ perfusion.Nursing diagnosis and intervention Constipation related to immobility,change in diet,possible fluid restriction and mediations.Administer
43、stool softeners as ordered.Provide bedside commode.Instruct patients to avoid straining.Provide foods high in fiber.If patient is unsuccessful,obtain laxative order from physician to facilitate easier bowel evacuation.1.Increased activity and ambulation as tolerated to increase peristalsis and bowel
44、 motility.Nursing diagnosis and intervention Sleep pattern disturbance related to complex treatment regimen,pain,anxiety,stressful environment and frequent interruptions.Monitor flow of people into patients room to reduce nose and confusion and prevent sensory overload.Plan nursing care to provide o
45、ptimal rest to encourage myocardial healing.Provide calm,restful environment to reduce stimuli and promote sleep.Attempt to maintain patients sleep-wake cycle.1.If patients condition in stable,do not awaken for vital signs so that patient may have an uninterrupted sleep cycle.Nursing diagnosis and i
46、ntervention Ineffective management of therapeutic regimen related to lack of knowledge of disease process,rehabilitation,home activities,diet,and medications.Teach at patients level of understanding to ensure that the information is understood and to increase likelihood of behavior change.Provide gu
47、ideline with rationale for recommendation actions to be taken.Make recommendations to patient in a realistic manner.Include family when information is given,especially regarding homecoming,to get cooperation of the patients most significant support system.1.Be specific when giving discharging instructions.
