hypertrophic obstructive cardiomyopathy
Introduction
Introduction to hypertrophic obstructive cardiomyopathy Hypertrophic obstructive cardiomyopathy has been referred to as subaortic muscle obstruction. In 1952, Davies reported that five of his brothers and sisters had the disease, and three of them had sudden death. In 1958, Teae described hypertrophy of the ventricular septum, which was much thicker than the left ventricular free wall. The cardiomyocytes are thick and short, the arrangement is disordered, and the lateral connection between the cells is called asymmetrical ventricular septal hypertrophy. It is considered to be a type of primary cardiomyopathy after 1960. It accounts for about 20% of all types of cardiomyopathy. It is called idiopathic obstructive cardiomyopathy, idiopathic hypertrophic aortic stenosis or hypertrophy. Type obstructive cardiomyopathy. About 30% of the cases have a family history and may have genetic factors. basic knowledge The proportion of illness: 0.004% Susceptible people: more common in the elderly over 50 years old Mode of infection: non-infectious Complications: arrhythmia, endocarditis, sudden death
Cause
Causes of hypertrophic obstructive cardiomyopathy
Genetic (25%):
There may be many people in a family, suggesting that it is related to heredity. Matsumori found that the detection rate of HLADRW4 was as high as 73.3%, and the detection rate of the control group was extremely low. The HLADR system is one of the genetic genes, which has a regulatory effect on immune response. The disease is related to heredity.
Endocrine disorders (15%):
Patients with dystrophic cell tumors have more hypertrophic cardiomyopathy. Intravenous infusion of a large amount of norepinephrine can cause myocardial necrosis. In animal experiments, intravenous infusion of catecholamine can cause hypertrophy of the heart. Therefore, it is considered that hypertrophic cardiomyopathy is an endocrine disorder. Caused.
Prevention
Hypertrophic obstructive cardiomyopathy prevention
The course of the disease is slow, the prognosis is uncertain, and it can be stable for many years. However, once symptoms appear, it can gradually deteriorate. Sudden death and heart failure are the main causes of death. Sudden death is more common in children and young people. Its appearance is related to physical activity, with or without Symptoms or obstruction related, high ventricular wall muscle thickness, family history of sudden death, persistent ventricular tachycardia is a risk factor for sudden death, possible mechanisms of sudden death including rapid ventricular arrhythmia, sinus node lesions and Cardiac conduction disorders, myocardial ischemia, diastolic dysfunction, hypotension, the two most important, the occurrence of atrial fibrillation can promote heart failure, a small number of patients with complications such as infective endocarditis or embolism.
Complication
Hypertrophic obstructive cardiomyopathy Complications, arrhythmia, endocarditis, sudden death
Complications of hypertrophic obstructive cardiomyopathy are:
(1) Arrhythmia: More common, in which ventricular arrhythmia and atrial fibrillation require treatment.
(2) Endocarditis: The incidence is low due to the adhesion of bacteria in the blood to the blood flow disorder in the heart, such as the aortic valve and the mitral valve.
(3) heart block: can occur in the sinus node and atrioventricular node, more common, is also one of the factors affecting drug treatment.
(4) sudden death: less, it may not have any signs, systematic evaluation may help identify such high-risk patients, but it is the most serious complication of hypertrophic cardiomyopathy, ventricular tachycardia caused by ventricular tachycardia is the most common Serious bradycardia is also a factor that cannot be ignored.
Symptom
Symptoms of hypertrophic obstructive cardiomyopathy Common symptoms Water rushing pulse after labor, angina pectoris, systolic murmur, visceral obstruction, palpitations, cardiac structure, abnormality, dizziness, dizziness, myocardial grayness and relaxation
Clinical manifestation
Clinical symptoms include shortness of breath, fainting or dizziness, and post-operative angina. Similar to aortic stenosis, about 10% of cases have palpitations or systemic embolism due to paroxysmal or persistent atrial fibrillation, and congestive heart in advanced cases. Failure, sitting breathing and pulmonary edema. Common signs include apical beats, shifting to the left, common lifting impulses or dual impulses. The lower sternal left margin or apical area can be heard in the mid-systolic murmur, transmitted to the base of the heart, often accompanied by tremors, accompanied by In the case of mitral regurgitation, the apical region presents a full systolic murmur, the second heart sound splits, and the third heart sound or the fourth heart sound can also be heard, but the systolic jet-like sound is not heard, and the peripheral arterial shock wave is strong. The vanishing wave is small, similar to the water pulse.
Examine
Examination of hypertrophic obstructive cardiomyopathy
The examination methods that are helpful in the diagnosis of this disease are:
(1) Chest X-ray examination: the heart shadow is enlarged, the left ventricle is enlarged, but there is no sign of ascending aorta enlargement or calcification of the valve leaflet. In the advanced case, the left atrium and the right ventricle may also increase, and the blood vessels in the lung field are stagnation.
(2) Electrocardiogram examination: showing left ventricular hypertrophy and strain, sometimes abnormal Q waves appear in the front aVL and I leads, and some cases show complete right bundle branch, left bundle branch or left anterior branch block and left atrial hypertrophy .
(3) Cardiac catheterization: right heart catheterization can show signs of elevated pulmonary artery pressure or right ventricular outflow tract stenosis. Left ventricular catheterization shows significant increase in left ventricular end-diastolic pressure, and systolic phase between left ventricular lumen and outflow tract. Pressure gradient, aortic or peripheral arterial pressure waveform showed a rapid rise in the ascending branch, showing a double peak, then slowly descending, decreased aortic pulse pressure after ventricular extrasystole, taking nitroglycerin, isoamyl nitrite, isoproterenol Prime, digitalis and physical labor and Valsalva action after myocardial contractility, increased left ventricular outflow obstruction, can lead to increased acoustics, increased contraction pressure gradient.
(4) Selective left ventricular angiography can show the ventricular septum in the anterior superior hypertrophy of the outflow tract and the anterior mitral valve leaflet in the posterior wall of the outflow tract, the left ventricular cavity is curved, and the left ventricular volume is small and the papillary muscle is thick at the end of the contraction.
(5) Left ventricular angiography can still determine whether there is mitral regurgitation, adult patients should be used for coronary angiography to understand the presence or absence of coronary artery lesions.
(6) Echocardiography: showed significant thickening of the left ventricular wall, ventricular septal thicker than the posterior wall of the ventricle, small left ventricular cavity, stenosis of the outflow tract and systole of the anterior mitral valve.
Diagnosis
Diagnosis and differentiation of hypertrophic obstructive cardiomyopathy
Patients with ventricular outflow tract obstruction have characteristic clinical manifestations and are not difficult to diagnose. Echocardiography is an extremely important non-invasive diagnostic method, which is helpful for both obstructive and non-obstructive patients. 18mm and mitral systolic advancement, enough to distinguish between obstructive and non-obstructive cases, cardiac catheterization showed that the left ventricular outflow tract pressure difference can establish a diagnosis, ventricular angiography is also valuable for diagnosis, clinically on the left sternal left margin Systolic murmur should consider this disease, affecting hemodynamics with physiological action or drug action and observing the change of murmur is helpful for diagnosis. In addition, the following differential diagnosis is necessary.
(1) Ventricular septal defect: The systolic murmur is similar, but it is full systole, and there is no murmur in the apical region. Echocardiography, cardiac catheterization and cardiovascular angiography can be distinguished.
(B) aortic stenosis: symptoms and murmurs are similar in nature, but the murmur is higher, and often there is a squeezing jet sound in the aortic valve area, the second sound is weakened, there may be early diastolic murmur, X-ray shows the ascending aorta Dilation, physiological movements or drug effects have little effect on the murmur. Left heart catheterization shows that the systolic pressure difference exists before and after the aortic valve, and echocardiography can identify the lesion.
(C) rheumatic mitral regurgitation: murmur is similar, but mostly for the full systolic period, vasoconstrictor or squatting makes the murmur stronger, often accompanied by atrial fibrillation, the left atrium is larger, echocardiography does not show ventricular septal defect .
(4) Coronary heart disease angina pectoris: ST-T changes and abnormal Q waves on the electrocardiogram are common to both, but coronary heart disease has no characteristic murmur, aortic multi-widening or calcification, hypertension and hyperlipidemia; echocardiography The interventricular septum is not thickened, but there may be segmental wall motion abnormalities.
