心肌疾病英文课件

1、心肌疾病（英文）心肌疾病（英文） Difinition Cardiomyopathy is a serious disease in which the heart muscle becomes inflamed and doesnt work as well as it should It can be classified as primary or secondary. Primary cardiomyopathy cant be attributed to a specific cause, such as high blood pressure, heart valve diseas

2、e, artery diseases or congenital heart defects. Secondary cardiomyopathy is due to specific causes ClasificationClasification(1995 (1995 WHO/ISFC) WHO/ISFC) There are four main types: Dilated cardiomyopathy Hypertrophic cardiomyopathy Restrictive cardiomyopathy Arrhythmogenic right ventricular dyspl

3、asia Dilated cardiomyopathyDilated cardiomyopathy This type of cardiomyopathy is characterized by a dilatation and impaired contraction of the left or both ventricles Importances The incidence and prevalence of cardiomyopathy appears to be increasing. The reported incidence is 0.013-0.084% Cardiomyo

4、pathy is an important cause of morbidity and mortality among the worlds aging population Sex: men/women is 2.5/1 Age: All age groups are affected. However, studies suggest that 50% of patients with new onset of disease are younger than 2 years CAUSESCAUSES Cardiomyopathies have many causes, includin

5、g nutritional deficiencies, deposits in the heart muscle associated with medical conditions, anemia, stress, viral infections, alcoholism, coronary artery disease, and others There is no identifiable cause, although it is suspected to be an end stage of myocarditis SYMPTOMSSYMPTOMS Symptoms often de

6、velop gradually and usually include symptoms of right heart failure and/or left heart failure Because the body compensates for dilated cardiomyopathy, the disease may have no symptoms initially. As the condition worsens, the heart may perform normally when a person is resting, but may cause symptoms

7、 during periods of exercise or psychological stress symptoms fatigue shortness of breath on exertion, orthopnea (breathing difficulty when lying down), waking up at night short of breath swelling of the ankles excessive urination at night irregular heartbeat (palpitations-a feeling of racing or skip

8、ping of the heart) decreased urine output (may not include at night) DIAGNOSIS A physician diagnoses dilated cardiomyopathy after a physical examination check for shortness of breath during exercise and weakness The physician may also hear rales, or wet crackles, through a stethoscope, indicating fl

9、uid in the lungs Neck and Lungs Jugular venous distention (as an estimate of central venous pressure) Hepatojugular reflux Large cv wave (observed with tricuspid regurgitation) Crackles (pulmonary rales) Signs of pleural effusion may be noted Inspection and palpation Palpate for heaves, shifted poin

10、t of maximal impulse, and cardiomegaly (broad and displaced point of maximal impulse, right ventricular heave). The normal apical impulse should be approximately the size of a quarter and should be located in one (fourth or fifth) intercostal space. The apical impulse is normally within 10 cm of the

11、 midsternal line Auscultation Murmurs (with appropriate maneuvers),tachycardia, S2 at the base (paradoxical splitting, prominent P 2), S3, and S 4 may be noted An irregularly irregular rhythm (atrial fibrillation) may be noted Gallops are almost always present in persons with DCM Abdomen and others

12、Percussion and palpation of the liver may reveal hepatomegaly due to elevated venous pressure, infiltrative disease, hepatojugular reflux, or ascites Observe for cardiac cachexia, peripheral edema, cyanosis, and clubbing TESTS FOR DETECTIONTESTS FOR DETECTION To confirm the diagnosis, the physician

13、may order tests, including: Blood tests; Chest x ray; Echocardiogram; Electrocardiography (ECG) Cardiac catheterization and angiography X-ray This very large heart has a globoid shape because all of the chambers are dilated. It felt very flabby, and the myocardium was poorly contractile Doppler Echo

14、 Marked dilation of the left ventricle with global hypokinesia is the hallmark of the disease. Left ventricular ejection fraction 50%. Left ventricular walls are thin and areas of dyskinesis may be observed. The left atrium is also dilated. varying degrees of mitral regurgitation Electrocardiogram E

15、CG changes are usually nonspecific Low voltage complexes Presence of Q waves and inversion of T waves in leads I, II, aVL, and V 4 through V6 (anterolateral infarction pattern) Significant arrhythmia Myocardial biopsy The number of biopsy specimens collected should be limited to the minimum required

16、 (usually 4-8) Myocyte hypertrophy and fibrosis without lymphocytic infiltrate TREATMENTSTREATMENTS Hospitalization may be required of patients when symptoms of dilated cardiomyopathy are severe. Treatment for dilated cardiomyopathy is focused on relief of symptoms, just as is for other types of car

17、diomyopathy, and is essentially the same as the treatment of heart failure Medications Medications may include digitalis, Angiotensin converting enzyme (ACE) inhibitors,Anticoagulants,Beta- blockers,Calcium channel blockers, Vasodilators ,diuretics, nutritional supplements, or other cardiac medicati

18、ons Surgical CareSurgical Care A heart transplant may be considered if heart function is very poor Diet and others A low-salt diet may be recommended to patients and fluid intake may be restricted in some cases. Physical activity may be restricted as symptoms progress Smoking and alcohol cessation r

19、ecommendations may be given, because these habits make symptom of dilated cardiomyopathy worse COMPLICATIONSCOMPLICATIONS Congestive heart failure Cardiac arrhythmias, including lethal arrhythmias Pulmonary (lung) edema Total failure of the heart to function (circulatory collapse) Side effects of me

20、dications, including low blood pressure (hypotension), light headedness, fainting, lupus reaction, headache, GI upset, and digitalis toxicity HYPERTROPHIC HYPERTROPHIC CARDIOMYOPATHY CARDIOMYOPATHY Hypertrophic cardiomyopathy is a primary cardiac disease characterized by an inappropriate myocardial

21、hypertrophy, which occurs in the absence of an obvious hemodynamic load such as aortic stenosis or systemic hypertension HISTORY AND OTHER HISTORY AND OTHER NAMES NAMES Hypertrophic Cardiomyopathy was first recognised in the late 1950s. The condition has been known by a number of names including Hyp

22、ertrophic Obstructive Cardiomyopathy (HOCM), Idiopathic Hypertrophic Sub-aortic Stenosis ( IHSS) and Muscular Sub-aortic Stenosis. The general term Hypertrophic Cardiomyopathy (HCM) is now most widely used THE CAUSE The cause of Hypertrophic Cardiomyopathy is not yet known. In the majority of cases

23、the condition is inherited. In others there is either no evidence of inheritance or there is insufficient information about the individuals family to assess inheritance. In affected families the condition usually passes from one generation to the next and generations are not skipped A Family Tree NE

24、W DISCOVERIES Recently research has identified abnormalities in at least 6 related genes that are important in the development of heart muscle cells. In approximately 50-60% of families, affected individuals are found to have a mutation in the gene for myosin, troponin T, alpha tropomyosin, cardiac

25、myosin binding protein-C, or the essential and regulatory light chains. These are important proteins for the contraction of the heart pathology an excessive thickening of the muscle. Abnormal myocardial fiber arrangement which interferes with the proper diastolic sequence of relaxation. Abnormal myo

26、cardial calcium ion handling resulting in high cellular calcium ion concentration in the region of myofibrillar contractile proteins and delayed re-uptake of calcium ion by the sarcoplasmic reticulum resulting in prolonged relaxation. Ischemia. Myocardial fibrosis LEFT VENTRICULAR OUTFLOW TRACT (LVO

27、T) OBSTRUCTION Approximately 25% of patients with hypertrophic cardiomyopathy manifest variable degree of LVOT obstruction. In some, the obstruction or gradient is absent at rest but this can be provoked by exercise or other physiologic or pharmacologic means mechanism of LVOT obstruction Asymmetric

28、 Septal Hypertrophy mechanism of LVOT obstruction Asymmetric Septal Hypertrophy with Obstruction The mechanism of LVOT obstruction The thick upper septum protrudes in the LVOT reducing the orifice size. Blood flowing through this narrowed LVOT causes a Venturi (suction) effect which draws the anteri

29、or leaflet of the mitral valve towards the septum, further reducing the LVOT orifice size. Simultaneously, as a result of systolic anterior movement of the mitral valve (SAM), there is functional mitral regurgitation symptom dyspnea :Shortness of breath Exercise capacity may be limited by breathless

30、ness and fatigue Chest pain pain may occur at rest or during sleep and may persist Palpitation Syncopy/dizziness Sudden death PHYSICAL EXAMINATION PHYSICAL EXAMINATION The systolic murmur is characteristically crescendo-decrescendo and starts a little after the onset of S1. It is best heard at the l

31、eft lower sternal border and radiates to the base, but unlike systolic murmur of valvular aortic stenosis, it does not radiate to the carotids. murmur The intensity of the murmur can be varied by various physiologic and pharmacologic interventions. Tthe murmur (and gradient) can be intensified by de

32、creasing preload (decrease venous return) by abrupt assumption of upright posture or by Valsalvas maneuver. The murmur intensity can be diminished by increasing afterload (squatting), or by increasing preload (leg raising in supine position) The murmur of mitral regurgitation is prominent in the api

33、cal region and shows the same directional changes in response to the interventions noted above Electrocardiogram or ECG Electrocardiogram or ECG Main features include left ventricular hypertrophy (LVH) pattern and the presence of prominent Q waves which resemble Q waves of myocardial infarction (pse

34、udo- infarction pattern). Ambulatory electrocardiogram may reveal atrial and ventricular arrhythmias including non- sustained ventricular tachycardia (NSVT) Echocardiogram or ECHO Echocardiogram or ECHO include hypertrophic walls, ASH, and septal wall to posterior wall ratio of 1.3:1. In patients wi

35、th HOCM, there is presence of SAM. Left ventricular chamber is normal or small; left atrium may be enlarged. Color Doppler studies provide additional hemodynamic information Cardiac Catheterisation Cardiac Catheterisation shows a gradient between the main left ventricular chamber and the subaortic c

36、hamber proximal to the obstruction. This pull back tracing differentiates obstructive hypertrophic cardiomyopathy from aortic stenosis Genetic testing Genetic testing may play an important role in helping doctors rule out other diagnoses. For example, in patients who have a small increase in wall th

37、ickness (like trained athletes with ventricular hypertrophy), and some patients with constant high blood pressure who are thought to have HCM TREATMENT TREATMENT Drug Treatment Drug treatment or medication is primarily given when a Drug treatment or medication is primarily given when a person has so

38、me or all of the symptoms described earlier Alcohol Septal Ablation A catheterization is performed, alcohol is injected into the septum through a small coronary artery. This causes a controlled myocardial infarction Pacemaker dual chambered pacing would relieve obstruction, eliminate most symptoms a

39、nd thin the walls of the heart Surger yre moving a small amount of muscle from the ventricular wall Drug Treatment Drug Treatment Beta-Blockers These drugs reduce heart rate, decrease myocardial contractility, prolong diastolic filling time and possess anti-arrhythmic properties especially against e

40、xercise- induced arrhythmias Calcium Antagonists Anti-Arrhythmic Drugs Anticoagulants Diuretics Antibiotics Dual Chamber Pacemaker Dual Chamber Pacemaker It is believed that pacemaker therapy alters the sequence of contraction which reduces LVOT gradient and improves symptoms Long term benefits, how

41、ever, are questionable Restrictive cardiomyopathy It is a disorder of the heart muscle in which the walls of the ventricles become stiff, but not necessarily thickened, such that they resist normal filling with blood. There is no cure. Treatment aims to ameliorate symptoms caused by the backup of bl

42、ood into the lungs and veins of the neck and liver Symptoms Patients with RCM present with signs and/or symptoms of heart failure such as fatigue, shortness of breath, tissue swelling (oedema) and abdominal enlargement Up to a third of patients may present with an embolic complication. Abnormal hear

43、t rhythms and palpitations are common whatever the underlying cause of the disease diagnosis The diagnosis of RCM is usually based a physical examination, an electrocardiogram (ECG) and an echocardiogram. Magnetic resonance imaging (MRI) can provide additional information about the structure of the

44、heart. In some patients a precise diagnosis may require catheterisation of the heart to measure pressures and to perform a biopsy of the heart muscle (removal and microscopic examination of a specimen), which may enable the doctor to identify the infiltrating substance Treatment As the onset of symp

45、toms in RCM is often very insidious, the diagnosis of RCM may be made late in the course of the disease. There is no specific treatment for RCM, and the aims of medical therapy are to improve symptoms of heart failure, treat cardiac rhythm disturbance and to prevent thromboembolism. Pacemakers are i

46、ndicated for patients with slow heart rates or heart block Arrhythmogenic right ventricular dysplasia ARVD is a rare type of cardiomyopathy in which the muscle tissue in the lower-right chamber of the heart (right ventricle ) dies. The dead muscle tissue is replaced by fat Patients can develop dange

47、rous arrhythmias or even go into cardiac arrest, particularly when under physical or emotional stress. Studies have shown that ARVD is a significant cause of sudden cardiac death among young athletes Names Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Even though this disease has been recog

48、nised only recently, These are not formal guidelines for assessment or treatment Muscle cells become disorganised and are replaced by fibrous and fatty tissue Patchy involvement of the right ventricle may lead to one or more sites of abnormal electrical activity SYMPTOMS of ARVC SYMPTOMS of ARVC Palpitation light-headedness fatigue blackout or collapse or syncope symptoms o