Ischemic heart disease

Overview of ischemic heart diseases, including atherosclerosis caused by coronary artery stenosis or obstruction. Myocardial ischemia caused by left ventricular aneurysm. cardiac embolism after ventricular septal defect and papillary muscle ischemia caused by mitral regurgitation. is the old common multiple of acquired heart disease. This section focused on coronary atherosclerotic stenosis or obstruction. Coronary artery wall atherosclerosis causing vascular cavity narrow crown blocked blood flow, myocardial blood supply shortage obstruction can cause severe myocardial infarction. Nearly 40 years ago, coronary atherosclerotic heart disease incidence in China gradually increased. According to the Shanghai Medical University statistics, in 1948 ~ 1958 hospitalized patients with heart disease, coronary heart disease accounted for only 6%; 1959 ~ 1971 accounted for 18%; 1972 ~ 1979 increased to 29% At present, various types of heart disease in the top of the list. Etiology of coronary atherosclerosis pathogenesis more complicated, and we have not yet fully understood. Based on a large number of epidemiological and experimental data, the major causative factors : high-calorie, high-fat, high-sugar diet, smoking, high cholesterol, hypertension, diabetes, obesity, physical activity is too small, intense mental, emotional, easily agitated, nervous, middle-aged and elderly males, low high-density lipoprotein, blood coagulation dysfunction. There may be a few cases of familial genetic factors. Pathological changes in coronary anatomy : coronary myocardial blood supply and oxygen to the blood vessels and anatomy of its many variations. Under normal circumstances have left coronary artery, the right two, opening the ascending aorta to the left and right coronary sinus flap, sometimes from aortic issued another smaller coronary deputy. Left main coronary artery diameter of about 4 ~ 5 mm and a length of about 0.5-2cm from the ascending aorta issued, Pulmonary total dry in the direction of the left and after running, In the pulmonary trunk and left atrial appendage along the left atrioventricular groove move downward into anterior descending and circumflex branch. Anterior descending branch of the left main coronary artery continuity between rooms along the ditch before the downlink, bypassing the apex notch arrived heart wall, Room after the furrows between 1 / 3 and the right coronary artery after descending line. Anterior descending branch issued Cone left, diagonal branch, the anterior branch of the left ventricle and right ventricle septal ago, and a former branch and other branches, Regional blood supply is the aortic and pulmonary roots cadres, some of the left atrial wall, left ventricular anterior wall, part of the anterior wall of the right ventricle. Most ventricular septal (upper and the former Department), the apical region and the former papillary muscles, and so on. Circumflex branch of the left main coronary artery is issued, the left atrioventricular groove along the front close to the bottom of the left atrial appendage, left running back, then the left edge of cardiac septal surface arrived at the downlink. Circumflex branch of the branch a lot of variation, several major branches help the Left margin of support, left ventricular posterior collateral and along the left atrioventricular groove of AV support. AV support sometimes (about 10%) longer, and from the terminal issued after descending artery and the atrioventricular node. 30% of the circumflex branch of the human body still issued sinus artery. Circumflex branch of the regional blood supply is left ventricular wall and back wall of the left atrium, sometimes feeding of ventricular septal hand, papillary muscles, After the papillary muscles, ventricular septal part, the atrioventricular node, atrio-ventricular bundle and sinus. Right coronary artery valve from the right coronary sinus issued after close to the bottom of the right atrial appendage, right atrioventricular groove along the outside down OK. Arrived at the atrioventricular groove of ventricular and atrial septal and atrial and ventricular septal rear edge, divided into two, right posterior descending branch in the latter direction ventricular apical groove, another smaller atrioventricular node artery to the top. The main right coronary artery branches Right Cone support, the right support, the sinoatrial node support, right ventricular anterior branch, the right ventricle after the collateral, After ventricular septal, posterior descending artery and the atrioventricular node, and so on. Right coronary artery supplying blood region, including the right atrium, sinus, and the right ventricular outflow tract, pulmonary cone, and the right ventricular wall. posterior wall of the right ventricle, ventricular septal under 1 / 3 and the atrioventricular node. Right coronary artery advantage of the patients was part of the blood supply and left ventricular apex. Coronary about the distribution of cardiac septal face considerable regional variation, feeding the larger branch of coronary stenosis occurred, myocardial ischemic injury in a wider regional, more serious illness (Figure 3). (3) right anterior oblique (4) the left anterior oblique coronary anatomy Figure 3 [-] under the Cross District is the heart after heart Bilateral ventricular wall, atrial and ventricular septal junction of the blood supply, left, distribution of the right coronary artery can be divided into three main categories : a) the right coronary artery advantages of this type most common type, about 80%. Right coronary artery and long rough, the supply of blood to the right ventricular wall and across the heart of the district Cross after descending from the blood supply to part of the left ventricular wall and ventricular septal rear. 2) Left-edge coronary smaller right coronary artery and the left circumflex coronary artery issued after descending blood supply to the left, right ventricular wall and interventricular septum. 3) The left and right coronary balance-left and right coronary artery after each issued a descending blood to the left, right ventricular wall (Figure 4). (1) dominant right coronary artery (2) The advantage of the left coronary artery-3) left and right coronary-balance plans four left, right coronary artery distribution of pathological anatomy : coronary atherosclerosis occurred in the majority of the main branches of the coronary artery proximal, The distance from the aortic opening about 5 cm within the scope of the Standing at the atrioventricular groove, enveloping the surrounding adipose tissue to the main coronary artery support, lesion surgery for the treatment of favorable conditions. With hypertension or diabetes, the disease is broad in scope, involving small coronary artery branches. Atherosclerosis main coronary artery intimal involved, endometrial lesions in the early and middle within cells containing lipid and lipid giant phagocytic cell infiltration intimal thickening showed yellow spots. With the various causes of the endometrium and endometrial cell injury increased permeability, increased lipid infiltration, Dot gradually increasing expansion, forming plaque or stripes. Endometrial there focal dense layer of collagen and endometrial lesions week that the cavity caused vascular stenosis or obstruction. Lesions of coronary blood flow reduction, exercise or resting at the regional myocardial blood supply is insufficient. Severe cases may have myocardial infarction. Coronary Atherosclerosis lesions can hemorrhage, and thrombosis of aneurysms. Atherosclerotic lesions bleeding when entered the blood lipid cavity, it can lead to distal embolization and induced thrombosis, vascular wall hematoma can be gradually formed granulation tissue and fibrosis. Endometrial bleeding may cause acute coronary collateral circulation and branches cramps, increase the extent of myocardial ischemia. Thrombosis and bleeding often there is a cake could also lead to the distal vascular thrombosis and vascular fibrosis. Endometrial coronary atherosclerosis vascular necrosis of the middle wall with aneurysms were very rare. The majority of cases only one vascular aneurysms occurred in diameter up to 2.5 cm, the cavity may contain gore, But vascular channels remain open. Atherosclerotic lesions caused by coronary artery stenosis, coronary limited to a branch, and the development process has been slow. and vascular lesions were adjacent to the traffic between coronary support significant expansion, we can establish an effective collateral circulation. Regional myocardial involvement can be adequate blood supply. Lesions involving multiple vascular, or stenosis faster progress in the process, collateral circulation less than fully established or issued cake blood, hematoma, thrombosis, vascular spasm, may cause serious cardiac ischemia or myocardial infarction. Regional myocardial tissue lesion shrinking, or necrosis, or even rupture of the future formation of fibrous scar, Myocardial contractile function suffered serious damage may occur arrhythmia or cardiac pump failure. Myocardial ischemia in the larger the area, more than the harm caused serious. The supply of the left coronary artery blood flow crown up, it branch of the left coronary artery and heart disease caused by the obstruction change right coronary artery is more than serious. Pathophysiological : 100 g per myocardial blood flow per minute 60-80m1. Compared with body tissue per 100 g per minute 7 ml of blood flow of about 10 times. Crown recycling is another feature of diastolic blood flow the most, while the systolic cardiac revascularization due crushed, Crown cycle, reduced blood flow, and other bodily organ in systolic arterial perfusion pressure at the highest maximum blood flow. Myocardial oxygen strong capillary intake from about 65 ~ 75% of oxygen. Under normal circumstances, each 100 g per minute myocardial oxygen 8 ~ 10ml. and the only body organ uptake from the blood of 25% oxygen, per minute per 100 g oxygen only about 0.3 ml. Campaign, the cardiac output increased significantly, cardiac workload, increased myocardial oxygen demand. Because blood from further improve oxygen uptake little room for the need by expanding the coronary lumen. the highest increase blood flow to fit the requirements of increased oxygen demand. Crown is sensitive to the cycle ability to regulate, regulate blood flow crown factors : arterial perfusion pressure, the crown vascular resistance, heart rate, Cardiac systolic and diastolic time, blood CO2 tension and oxygen tension, pH and neurohumoral factors. Myocardial energy metabolism of glucose material, fatty acids, such as lactic acid. In the crown for lack of blood circulation, myocardial metabolism in hypoxic conditions, lower fatty acid oxidation, carbohydrate oxidation Habitat major position, but under hypoxic conditions, Decomposition of glucose and glycogen after the energy supply can only aerobic metabolism of a small part of it. Myocardial ischemia sustained over 20 minutes mitochondria caused irreversible degeneration of the complex, myocardial necrosis, loss of activity of enzymes in the clinical has angina, arrhythmias and congestive heart failure symptoms.