rheumatic mitral regurgitation

Introduction

Introduction to rheumatic mitral regurgitation Rheumatic mitral regurgitation is a rheumatic fever invading the mitral valve. The most common lesion is thickening of the valve fibrosis, junction fusion, narrow mouth, and the formation of simple mitral stenosis. About 1/3 of cases of mitral stenosis are associated with insufficiency. Simple mitral regurgitation is rare, accounting for only about 5% of rheumatic mitral valve disease. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: arrhythmia acute heart failure

Cause

Rheumatic mitral regurgitation

Rheumatic fever is a leading factor in the pathogenesis of this disease, and there are two situations:

(1) Rheumatic mitral stenosis with regurgitation, due to rheumatic fever caused by long-term repeated inflammatory changes of the mitral valve, mitral valve fibrosis, thickening, stiffness, junction fusion, resulting in stenosis of the valve, at the same time The valve leaflets are deformed by fibrosis, and the free edge of the valve is thickened due to fibrosis or calcium deposits. The curl is not flat, so that the anterior and posterior leaflets cannot close together when the ventricle contracts. The chordae papillary muscle is also fibrotic due to fibrosis. The valve leaf is pulled toward the ventricular cavity, so that the valve leaf mobility is limited, hindering the opening and closing function of the valve, and the mitral valve has both stenosis and insufficiency.

(2) In the case of simple mitral regurgitation, although the valve has a certain degree of fibrosis and thickening, but the valve leaflet junction is not fused, blood flow through the mitral valve mouth and is unobstructed, the main lesion is the mitral annulus The reason for the enlargement of the annulus is that the acute rheumatic myocarditis causes the left ventricle to enlarge, the mitral annulus increases with the enlargement of the left ventricle, and the annulus of the posterior leaflet is more pronounced, resulting in a relative lack of leaflet area. The systolic valve can not be closed, such as when the acute phase of rheumatic fever is treated properly, the better the myocarditis, the left ventricle and annulus shrink, and return to normal, then the insufficiency can disappear, if there is no medical treatment or treatment in the myocarditis phase, then The left ventricle and annulus continue to increase. After several years, the left ventricle and annulus are further enlarged due to mitral regurgitation. The degree of regurgitation is also aggravated. When the heart contracts, the mitral valve leaflets cannot be closed. The tension that is subjected to increased, may be broken, and the wound caused by the impact of the left ventricular systolic blood flow may present a fibrin-like degenerative lesion.

Prevention

Rheumatic mitral regurgitation prevention

This disease is a disease that occurs due to rheumatism infection and affects the heart. Therefore, it is an effective measure to prevent and treat rheumatism, and it is also necessary to treat bacterial endocarditis in time.

Complication

Rheumatic mitral regurgitation complications Complications arrhythmia acute heart failure

The common complications of this disease are as follows:

(1) Low cardiac output: This is the main cause of early death in valve surgery. Since the use of good myocardial protection and improved operation, postoperative low cardiac output has been reduced, which is still a common serious complication. Care must be taken, as described above, using strong, cardiac, positive inotropic drugs.

(2) arrhythmia: after replacement of the valve under cardiac arrest, bradycardia or conduction block may occur at the spot, and isoproterenol may be intravenously instilled. If the epicardial electrode is placed at the end of the routine operation, the epicardial electrode may be temporarily placed. On-demand pacing transition, until cardiac function recovery, postoperative common arrhythmia is knot rhythm, atrial ventricular premature beats, ventricular tachycardia, and even the most severe ventricular fibrillation, etc., often with myocardial edema, valve Stimulation, stress enhancement, etc., hypokalemia, especially ventricular premature beats, the cause of ventricular tachycardia, more frequent need to intravenous lidocaine solution 50-100mg corrected and then infused with lidocaine solution ( 400mg/500m1) maintenance, while timely supplementation of potassium chloride, can also be used heart rhythm, amiodarone, verapamil and other anti-arrhythmia drugs, and even electric shock treatment.

(3) Left ventricular rupture: This is a serious complication only seen in mitral valve replacement, the incidence rate is about 0.5% - 2%, according to the location of the rupture can be divided into two categories: the first type of perforation in the posterior atrioventricular groove Most of them are caused by excessive resection of small valves, especially the extensive calcification of the valve has calcium blocks embedded in the atrioventricular ring; the second type of perforation is in the middle of the posterior side of the left ventricle adjacent to the papillary muscles, mostly due to excessive removal of the papillary muscles, or selection The artificial flap with a large number, the pressure of the ventricle wall by the valve frame, or the ventricular wall after the foot is stabbed, in addition, the left circumflex artery can be ligated, causing myocardial infarction, leading to rupture of the ventricle. The clinical manifestation is shortly after cardiac resuscitation. There is a large amount of blood overflowing from the pericardial cavity, or a large amount of blood is suddenly emerging from the chest drainage tube within a few hours after surgery. If the chest is found before the chest is closed, the extracorporeal circulation is immediately reconstructed, and the bleeding is found under the circulation, and the gap is sewed with a gasket. , or re-block the aorta, open the left atrium to remove the artificial flap, find the gap to suture, and then suture the artificial flap, about 30% of the patients are treated to save, post-operative detection, and then rescue, unprepared, die The rate is almost 100%, so it is necessary to pay attention to the preventive measures of this complication, such as avoiding excessive resection of the small flaps, only cutting the papillary muscles at the top, using artificial flaps with the atrioventricular ring or the left heart chamber, when the seat is not crowded Pressure chamber wall, etc.

(4) Endocarditis: Since the preoperative and high-dose broad-spectrum antibiotic therapy has been used, the incidence of postoperative endocarditis has decreased from 10% to 2% to 4%. Infected people are rare, but fungal infections rise instead. Early endocarditis occurs within 2 cases after surgery, mainly related to intraoperative factors such as intraoperative contamination, chest incision infection, mediastinal inflammation, pneumonia, etc. Later endocarditis occurs more often than urinary tract infections, gingivitis, tooth extraction or other minor surgical procedures. In the early stages, bacterial infections were mainly Staphylococcus and Gram-negative bacilli, and those with advanced infection were Streptococcus, grass. Streptococcus mutans is common, most people with fungal infections are seen in the early stage, and most of them are Candida and Aspergillus. The clinical manifestations of endocarditis are persistent high fever, heart murmur, splenomegaly, skin stasis, hematuria, etc. Peripheral arterial embolism, but this may also be the onset of fungal endocarditis, blood tests for leukocytosis, anemia and erythrocyte sedimentation rate, etc., blood culture is more positive diagnosis, fungi Dyed valves, often grown on artificial flaps into huge neoplasms, obstacle valve activity, echocardiography is a valuable diagnostic method, endocarditis mortality is high, up to more than 70%, the main cause of death It is heart failure, sepsis, cerebral embolism, renal failure, etc., in the treatment of bacterial infective endocarditis, the first choice of drug-sensitive antibiotics, a course of treatment for 4 to 6 weeks; fungal infection, then choose amphotericin B, in recent years To change to fluconazole, the internal medicine is not effective, the infection is not controlled, the heart failure is progressively worsened, or there is a huge embolism, then the valve replacement should be considered. The preventive measures are strict adherence to the aseptic operation during surgery. High-dose broad-spectrum antibiotics should be used before and after surgery. For long-term use of antibiotics, nystatin or clotrimazole and fluconazole should be added.

(5) thromboembolism: after mechanical valve replacement such as cage ball or roll disc, in patients with continuous anticoagulant therapy, the incidence of thromboembolism is still 4% to 5% per year, 30% during the 5-year period, 80 %, most embolization occurs within 3 months after surgery, but less common in 2 to 4 years after surgery. About half of patients have mild clinical manifestations of embolic episodes, which can be completely recovered in a short period of time without residual neurological symptoms, but 5% to 10% have non-fatal but severe neurological sequelae, and another 25% can cause death. In addition, after thrombosis, it can extend to the artificial valve orifice, or involve the valve column, resulting in stenosis or reflux. The opening and closing activities, the rate of thromboembolism in bioprosthetic replacement is lower, less than 2% per year, and the large left atrium with atrial fibrillation is more common. The incidence of follow-up for 5 years is less than 10%.

(6) Hemolysis: After the artificial flap is replaced, it may be accompanied by mechanical red blood cell destruction. From the red blood cell survival curve, the biological valve is slightly smaller than the mechanical valve, and the pressure gradient of the artificial valve across the valve also affects hemolysis, and the pressure gradient is The larger the hemolysis, the more hemorrhage and the artificial valve failure, the more hemolysis, clinically due to persistent hemolysis, about 50% of patients may have mild or moderate anemia, even hemoglobinuria, severe anemia May be associated with free hemoglobin and blood cell protein, increased lactate dehydrogenase, etc., most patients can take iron orally; such as ferrous sulfate 300mg daily, control of progressive anemia, severe or refractory anemia, need blood transfusion therapy, flap Severe hemolysis caused by circumferential leakage or valve failure may require surgery to repair the leak or replace the artificial flap to correct.

(7) Peripheral leakage: currently rare, which is related to the technique of suturing the artificial flap, such as the suture of the atrioventricular ring is not tight enough, the suture knotting is not tightened or the suture is broken, and there is also due to endocarditis. Partial annulus tissue secondary ulceration causes paravalvular leakage, clinical systolic murmur, but sometimes difficult to hear, need to be confirmed by echocardiography or left ventricular angiography, severe cases can cause acute heart failure and heart Membrane inflammation, anemia, etc., mild valve septum can not be treated, severe patients need to quickly diagnose, re-operation, add sutures at the paravalvular leak, repair holes, or remove artificial flaps, replace the new valve.

Symptom

Rheumatic mitral regurgitation symptoms Common symptoms After labor, systolic murmur, palpitations, pacing frequency increased, heart valve perforation, hemoptysis, right heart failure, fatigue

Mild lesions, good cardiac function compensation can have no obvious symptoms, severe lesions or longer duration may appear fatigue, palpitations, fatigue and fatigue after exhaustion, the incidence of acute pulmonary edema and hemoptysis is much less than mitral stenosis After clinical symptoms, the condition can deteriorate rapidly in a short period of time. Physical examination: The main signs are apical beats and shifting to the left. The apical area can hear the full systolic murmur, often to the left side of the midline. Conduction, the second sound of the pulmonary valve area hyperthyroidism, the first sound weakened or disappeared, advanced cases may present right heart failure and hepatomegaly, ascites and other signs.

Examine

Rheumatic mitral regurgitation

1. Electrocardiogram examination: The electrocardiogram of the milder case can be normal, and the heavier ones often show the left axis of the electric axis, the mitral valve P wave, the left ventricular hypertrophy and the strain.

2. X-ray examination: the left atrium and the left ventricle were significantly enlarged, and the X-ray examination of the swallowed sputum showed that the esophagus was displaced backwards.

3. Echocardiography: M-type examination showed that the mitral valve curve was bimodal or unimodal, and the rate of ascending and descending increased rapidly. The anteroposterior diameter of the left ventricle and left atrium increased significantly, and the posterior wall of the left atrium was obvious. In the case of sag, the stenosis can still show the square wave of the wall. The two-dimensional or tangential echocardiogram can directly show that the mitral valve is not completely closed when the heart contracts. Ultrasound Doppler detection shows diastolic blood. Turbulence can estimate the severity of incomplete closure.

4. Cardiac catheterization: Right heart catheterization can show elevated pulmonary and pulmonary capillary pressure and decreased cardiac output index.

5. Left ventricular angiography: Injecting contrast agent into the left ventricle, the contrast agent can be seen to return to the left atrium when the heart contracts, and the angiographic return flow is more, but the left ventricular discharge fraction is decreased.

Diagnosis

Diagnosis and diagnosis of rheumatic mitral regurgitation

It is not difficult to make a diagnosis based on clinical manifestations and laboratory data.

The murmur of mitral regurgitation should be identified by systolic murmur in the apical region of the following conditions:

(1) Relative mitral regurgitation may occur in hypertensive heart disease, aortic regurgitation or myocarditis caused by various causes, dilated cardiomyopathy, anemia, etc. due to left ventricle or apex The annulus is significantly enlarged, causing the mitral valve to be relatively closed and the apical systolic murmur.

(B) functional apical systolic murmur about half of normal children and adolescents can hear systolic murmur in the anterior region, loudness is 1 ~ 2 / 6 level, short, soft, do not cover the first heart sound, no atrium And the enlargement of the ventricle can also be seen in the high-power circulation state such as fever, anemia, hyperthyroidism, etc., and the noise disappears after the cause is eliminated.

(C) ventricular septal defect can be heard in the third to fourth intercostal space of the sternal border and rough full systolic murmur, often accompanied by systolic tremor, murmur to the apical region, apical beats are lifted, ECG and X-ray examination The left and right ventricles increased, echocardiography showed continuous interruption of ventricular septum, and echocardiography confirmed the presence of left-to-right shunt at the level of the ventricle.

(4) Tricuspid regurgitation The lower left rim of the sternum is smear and the localized squeaky squeak of the localized squeaky squeak. When the inhalation is increased, the murmur is enhanced by the increase of the blood volume. When the pulmonary artery is high, the pulmonary heart valve is the second heart sound. Hyperthyroidism, v-wave of the jugular vein increases, there may be liver pulsation, swelling, right ventricular hypertrophy can be seen by electrocardiogram and X-ray examination, and echocardiography can confirm the diagnosis.

(5) Aortic valve stenosis The aortic valve area or apical area of the heart can hear loud and rough systolic murmur, which is transmitted to the neck, accompanied by systolic tremor, which may have early contraction and apical beat. ECG and X-ray examination showed left ventricular hypertrophy and enlargement, and echocardiography can confirm the diagnosis.

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