A. Causes of heart valve disease formation.
1, streptococcal infection causing rheumatic heart disease is a common cause of heart valve disease.
The most common cause of heart valve disease is to cause rheumatic arthralgia, sore throat of these symptoms, and without treatment, these causes secondary to autoimmune diseases, it may affect the heart valves, in the heart valves will form some pathological changes similar to rheumatic nodules, mainly causing progressive fibrosis of the valves, thickening, and even calcification. This is the main type of heart valve disease, which manifests as stenosis and/or incomplete closure of one or several valves in the mitral, tricuspid, and aortic valves.
2, degenerative valve disease in the elderly is another cause of heart valve disease.
Age-related degenerative valve disease is a more common cause in Western countries, and in our country as life gets better there is also a gradual increase in the number of elderly people these diseases are also more and more frequent, this disease such as atheromatous plaques, degenerative lesions, and as the structural tissues of the elderly are degenerated, some valves produce incomplete closure, stenotic plaques, etc.
3, there are other factors that cause heart valve disease.
(1) ischemic cardiomyopathy (coronary artery disease, myocardial infarction): myocardial ischemia in patients with coronary artery disease, the papillary muscle dysfunction, resulting in the loss of the fixation of the valve by the tendon cords attached to the papillary muscle, so that the mitral or tricuspid valve prolapses and closes incompletely, forming regurgitant heart valve disease.
(2) Infectious lesions: Infective endocarditis, which used to be the basis of some congenital heart disease, may be atrial septal defect, ventricular septal defect, arteriovenous ductus arteriosus and other simple lesions, the patient may be due to a cold and fever germs into the blood, the heart cavity, these abnormal parts will be easy to multiply, resulting in the destruction of the valve, this condition is called infective endocarditis. Infective endocarditis usually occurs in the left heart, mainly in the aortic valve and mitral valve. It is commonly caused by bacterial and mycobacterial infections, which mainly cause valve perforation, tearing, and even destruction, resulting in mild to moderate valve closure insufficiency. Severe mitral valve infections cause septic abscesses of the papillary muscles or destruction of the mitral annulus leading to a chain-like mitral valve, resulting in severe mitral regurgitation, or lesions occurring in the aortic valve, resulting in severe aortic valve insufficiency, especially when heart failure occurs.
(3) Congenital heart valve disease, pediatric heart valve dysplasia, resulting in stenosis, insufficiency, etc.
(4) Other causes, such as tumor invasion and trauma, can also lead to valve lesions.
Regardless of the cause, valve changes can manifest as.
(1) restriction of valve opening, narrowing of the valve opening, and obstruction of blood flow through the valve;
(2) Inadequate valve closure and regurgitation of blood flow;
(3) both of these conditions coexist.
Valve dysfunction due to infective endocarditis and myocardial infarction has a rapid onset and patients can become significantly worse in a short period of time. However, the common wind heart disease and degenerative valve lesions are chronic, progressive and insidious, and most patients can be asymptomatic in the early stages and are only found to have the disease when they are seen on physical examination or when they feel panicky and shortness of breath after activity. In fact, such patients may have been experiencing heart valve disease for several years, or even more than 10 years.
Second, the impact of heart valve disease on heart function
1, mitral valve stenosis: normal human mitral valve orifice area is 4-6 cm2, when the valve orifice area is reduced by half that is the impact on transvalvular blood flow and defined as stenosis. The orifice area of 1.5 cm2 or more is mild, 1-1.5 cm2 is moderate, and less than 1 cm2 is severe stenosis. In severe mitral stenosis, the transvalvular pressure difference increases significantly, up to 20 mmHg, and measurement of the transvalvular pressure difference can determine the degree of mitral stenosis. Mitral stenosis mainly affects the left atrium and right ventricle, and is prone to atrial fibrillation and pulmonary hypertension.
2, mitral valve insufficiency: part of the blood ejected from the left ventricle during systole regurgitates to the left atrium through the insufficiently closed mitral valve orifice, and the blood returning to the left atrium from the pulmonary veins is summed up, filling the left atrium during diastole, resulting in increased volume load of the left atrium and left ventricle, enlargement of the left atrium and left ventricle, increase in the end-diastolic pressure of the left ventricle, and loss of compensatory function of the heart, resulting in left heart failure, pulmonary stasis, pulmonary hypertension, and right heart Failure.
3, aortic stenosis: adult aortic valve orifice ≥ 3.0 cm2. when the orifice area is reduced by half, there is still no significant transvalvular pressure difference during systole. When the orifice is ≤1.0 cm2, the left ventricular systolic pressure is significantly elevated and the transvalvular pressure difference is significant. Increased left ventricular pressure load causes centripetal hypertrophy of the left ventricular wall to maintain normal ventricular wall stress and left ventricular cardiac output. Increased ventricular wall stress, myocardial ischemia and fibrosis lead to left ventricular failure, and aortic stenosis mainly involves the left ventricle.
4, aortic valve insufficiency: increased left ventricular volume load, compensatory expansion of the left ventricle, and increased left ventricular diastolic pressure, leading to increased left atrial pressure, pulmonary stasis, and even pulmonary edema. Severe insufficiency can also lead to a decrease in diastolic pressure and inadequate myocardial perfusion, causing myocardial ischemia, leading to acute left heart failure and cardiac arrest in the acute phase.
5, tricuspid valve insufficiency: tricuspid regurgitation is systolic blood flow from the right ventricle back into the right atrium, resulting in a highly enlarged right atrium, increased pressure, venous blood return obstruction. Due to the increased load on the right ventricle, compensated and hypertrophic, it is easy to occur pulmonary hypertension and right heart failure.
6, tricuspid stenosis: rheumatic alone tricuspid stenosis is extremely rare, almost always accompanied by mitral and/or aortic valve lesions, and both tricuspid valve closure insufficiency. After stenosis formation, blood flow from the right atrium to the right ventricle is impaired, resulting in enlargement of the right atrium and increased pressure. Due to the obstruction of vena cava flow, the venous pressure increases for a long time, showing signs such as jugular vein anger, hepatomegaly, ascites and swelling of the extremities.
Third, the manifestation of heart valve disease in patients.
Patients who develop heart valve disease mainly have the following manifestations.
(1) dyspnea: especially after exertion, can be relieved after rest; paroxysmal dyspnea at night, can wake up after sleep, the need to sit and breathe.
(2) Cough: common, especially in winter, some patients have a dry cough when lying down. Sometimes it is accompanied by coughing up frothy mucus sputum.
(3) Hemoptysis: paroxysmal nocturnal dyspnea or bloody sputum during coughing, or sputum with blood; coughing up large amounts of pink frothy sputum; in severe cases, suddenly coughing up large amounts of fresh blood.
(4) Anterior chest pain (angina pectoris): often induced by exercise and relieved by rest.
(5) Syncope or near syncope: seen in 1/3 of those with symptoms. Most often occurs upright, during or immediately after exercise, and rarely at rest.
(6) Hoarseness and dysphagia: mainly occurs when the left atrium is significantly enlarged compressing the recurrent laryngeal nerve and compressing the esophagus.
(7) In more severe cases, there may be fatigue, poor appetite, distension in the liver area, hepatomegaly, abdominal swelling and edema of the lower extremities, and mild cyanosis of the cheeks and jaundice are seen.
Fourth, the treatment of heart valve disease.
1, drug therapy: there are various treatments for heart valve disease, many patients in the early stages of the disease, often or the use of non-surgical treatment, these patients is just the onset of people are young, but also no surgical treatment of mental preparation, the clinical indications for surgery is not clear, then control a certain amount of activity, with some drug therapy is mainly cardiac, diuretic, vasodilator and so on. If there is rheumatic activity, anti-rheumatic treatment is also carried out, which is the etiological treatment. Drug treatment depends on the patient’s complications, diuretic and potassium supplementation for edema, anti-infection treatment for valve infection, all these depend on the situation. Most of these patients will not affect their normal life and work, and patients should not have too much burden on their minds. Some of these patients do not need special treatment, but only regular review (cardiac ultrasound and chest X-ray, once every 1-2 years).
2, interventional treatment: Interventional treatment of heart valve disease is a minimally invasive treatment method, through the heart catheter on the patient’s narrowed valve expansion, to achieve a relief effect of stenosis. The newer and more cutting-edge is the interventional method to replace the valve, or the interventional method to correct the valve closure insufficiency. A small number of cases can be treated interventionally or as a pre-treatment for valve replacement.
3.Surgical treatment: It is the main radical means. Surgical treatment of heart valve disease is mainly direct treatment of the valve lesion, usually open-heart surgery under general anesthesia, to perform mitral valvuloplasty or mitral valve replacement, aortic valve replacement, etc., and tricuspid valvuloplasty or replacement if needed. One year after heart valve surgery, ultrasound should be reviewed to observe valve function. If the mechanical valve is torn or the biological valve is calcified, reoperation should be considered, and the risk of secondary surgery will increase compared with primary surgery.
V. Success rate and risk of valve replacement surgery.
Success rate: 95-99%, 98% on average; perioperative mortality rate 1-5%, 2.5% on average. The vast majority of patients can resume an active lifestyle and gain a new life through flap replacement. Risks (complications): are often the cause of the above mortality. These complications include (but are not limited to) hypovolemia, arrhythmias, respiratory distress syndrome, renal insufficiency, impaired consciousness, bleeding, hypertension, and heart failure. It is important to note that even with these postoperative complications, most patients can still be saved and recovered with supervised treatment and organ function support. Only 1-5% of them are really difficult to save.
VI. Choice of prosthetic heart valves.
There are two types of artificial heart valves to choose from: mechanical or biological valves.
Mechanical valve: advantages: mechanical valve implanted in the body, such as good maintenance and use of the right, long-term use will not have problems. Mechanical valve processing and production are under precise design and control, and is constantly evolving, and is now the third generation of mechanical valves are mainly bileaflet valves. Disadvantages: It is not a central flow type and its hemodynamics are not as good as those of a biological valve. There is noise. Requires lifelong anticoagulation.
Biologic valves: Advantages: closer to the natural valve configuration, central flow type, soft, less prone to mechanical failure, no noise, good biocompatibility, no long-term anticoagulation required. Disadvantages: not long durability, in vivo calcification decay destruction, from implantation to destruction time is several years to a dozen years.
Selection of prosthetic heart valves.
(1) Different options are needed depending on the patient. For example, a young woman who has not been married and has a childbearing requirement but has a serious heart problem that requires surgery may be advised to use a bioprosthetic valve, and the patient is advised to make the choice after being informed of the reasons. Alternatively, the patient may be advised to have a second operation to replace the valve with a mechanical valve after the biological valve has been replaced and the biological valve has failed after some years. If the patient is over 65 years of age, a bioprosthetic flap may be used, considering the inconvenience of medical care. If a gay man does not have the above two special conditions, he is free to choose between a biologic flap and a mechanical flap.
(2) Another consideration is the convenience of medical treatment, such as the need for blood sampling, laboratory tests, adjustment of medication, etc., and the possibility of other diseases requiring surgery afterwards, which is slightly more troublesome with a mechanical flap.