Mitral valve insufficiency
Introduction
Introduction to mitral regurgitation Due to anatomical and/or functional abnormalities of the mitral valve, the left ventricle partially returns to the left atrium when the left ventricle contracts, which is called mitral regurgitation. The most common cause of rheumatism is more common in northern China, mostly occurring in the 20-40 years old, more common in women. Rheumatic heart disease mitral insufficiency is caused by mitral valve damage left after repeated rheumatic inflammation, causing stiffness, deformation, and curling of the valve. Fusion and shortening of the valve junction, accompanied by chordae The shortening, fusion or rupture of the papillary muscle causes the mitral valve to be incompletely closed, causing a series of changes in hemodynamics. Other common causes include mitral valve prolapse, mitral valve degeneration, myocardial ischemia, infective endocardium, and congenital malformations. Most of the clinical manifestations are chronic. The prognosis depends mainly on the degree of valve insufficiency, atrial ventricular enlargement, cardiac function, basic etiology, recurrence of rheumatic activity, and whether complications occur. Early diagnosis and early treatment are the key. There is no specific cure for this disease, and surgical treatment can cure it. basic knowledge Sickness ratio: 0.05% Susceptible people: mostly occur in women aged 20-40 Mode of infection: non-infectious Complications: acute heart failure, heart failure, infective endocarditis
Cause
Mitral regurgitation
Acute mitral regurgitation (35%):
Caused by chordae rupture, valve damage or rupture, papillary muscle necrosis or rupture and prosthesis after prosthetic valve replacement, can be seen in infective endocarditis, acute myocardial infarction, penetrating or closed thoracic trauma and spontaneous spasticity Cable breaks.
Chronic onset (35%):
1, the most common cause of leaflet damage caused by rheumatic fever: account for 1/3 of all patients with mitral regurgitation, and more common in men. About 50% of patients have mitral stenosis.
2, coronary atherosclerotic heart disease (coronary heart disease): after myocardial infarction and chronic myocardial ischemia involving the papillary muscle and its adjacent wall muscle, causing papillary muscle fibrosis with dysfunction.
3, congenital malformation: mitral valve rupture, most common in endocardial pad defect or corrective cardiac transposition; endocardial fibroelastosis; parachute-type mitral valve malformation.
4, mitral annulus calcification: for idiopathic degenerative lesions, more common in elderly women. In addition, patients with hypertension, equine syndrome, chronic renal failure, and secondary hyperthyroidism are also prone to mitral annulus calcification.
5, left ventricular enlargement: obvious left ventricular enlargement caused by any cause, can make the mitral annulus dilatation, and the papillary muscles lateral displacement, affecting the closure of the valve leaflets, resulting in mitral regurgitation.
6, mitral valve prolapse syndrome.
Other rare causes (15%):
Connective tissue diseases such as systemic lupus erythematosus, rheumatoid arthritis, hypertrophic obstructive cardiomyopathy, and tonic sclerosing spondylitis.
Prevention
Mitral regurgitation prevention
1. Avoid excessive physical labor and strenuous exercise.
2. Limit sodium intake.
3. Protect the heart function.
4, diet attention to increase nutrition to improve resistance.
Complication
Mitral regurgitation complications Complications, acute heart failure, heart failure, infective endocarditis
1. Infective endocarditis: The most dangerous complication of mild to moderate mitral regurgitation is infective endocarditis, which can cause a sharp deterioration of cardiac function, which is more common than simple mitral stenosis.
2, atrial fibrillation and arterial embolism: mainly seen in advanced mitral regurgitation, often combined with mitral stenosis.
3, respiratory tract infection: long-term pulmonary congestion is likely to lead to pulmonary infection, can further aggravate or induce heart failure.
4, heart failure: is a common cause of complications and death.
5, embolism: due to the attachment of the wall thrombus, cerebral embolism is the most common.
Symptom
Mitral regurgitation symptoms common symptoms lower extremity edema end sitting respiratory fatigue cardiac structure abnormal atrioventricular tube malformation valve thickening mitral regurgitation liver enlargement dyspnea first heart sound hyperthyroidism
1, symptoms
The natural course and symptoms of mitral regurgitation depends on the severity of reflux, the compliance of the left atrium and the pulmonary hypertension, and whether there is a combination of cardiac and coronary disease, combined with its pathophysiological changes, may have the following corresponding Symptoms:
(1) Left ventricular compensation period: the asymptomatic period of compensation period is longer, before the occurrence of left ventricular failure (left heart failure), there may be several years or even more than 10 years of asymptomatic period, occasionally due to heart discharge Increased volume and increased apex beats cause mild palpitations.
(2) Left ventricular failure period: Once left heart failure occurs, the condition often develops rapidly. The main symptoms of chronic mitral regurgitation include:
1 Heart discharge decreased: visceral and limb blood supply caused by low cardiac output caused by left heart failure, manifested as fatigue, fatigue, dizziness and so on after activity.
2 pulmonary congestion symptoms: manifested as labor dyspnea, mild pulmonary congestion often in heavy physical labor, severe exercise, moderate, severe pulmonary congestion may occur paroxysmal nocturnal dyspnea, sitting breathing, but chronic mitral valve The incidence of acute pulmonary edema and hemoptysis is less common than mitral stenosis.
3 palpitations: often due to decreased cardiac output caused by compensatory heart rate, or due to concomitant arrhythmia, such as atrial fibrillation or premature contraction.
4 other:
A. Mild, moderate mitral regurgitation is complicated by infective endocarditis: there may be corresponding clinical symptoms.
B. Severe left ventricle, left atrial enlargement may have left chest pain and swallow discomfort.
(3) right ventricular failure period: involving the right ventricle and right heart dysfunction, may have upper abdominal fullness, liver pain, loss of appetite, oliguria, lower extremity edema.
2, signs
(1) Left ventricular compensation period:
1 The apex beats to the left and down.
2 apical area can reach a limited and powerful lifting impulse: suggesting left ventricular hypertrophy.
3 The heart of the voiced voice expands to the lower left.
4 characteristics of auscultation noise:
A. systolic murmur in the apical region: heard in the apex area a loud (3/VI level), rougher, higher pitch, longer time limit, full systolic hairy murmur, often cover the first heart sound, when involving the chord Or the sound of the papillary muscle may appear, according to the direction of the reflux beam, the noise can be left to the left, the left shoulder and the left rim of the sternum, the noise is often weakened during inhalation, slightly enhanced during exhalation, left heart Reduced in depletion, enhanced after heart failure correction.
B. The apical area has a third heart sound (S3): pathological S3, which is a characteristic feature of moderate to severe mitral regurgitation. The left ventricular filling is excessive during the early filling of the diastole, causing enlarged left ventricular wall vibration. Caused.
C. apical mid-diastolic murmur: patients with severe mitral regurgitation, due to increased blood flow rate and increased blood flow through the mitral valve during diastole, can be followed by a short, low-profile diastolic middle murmur after S3. The murmur does not extend to the late diastole.
D. Pulmonary valve area second heart sound (P2) division: the left ventricular systolic time interval is shortened, the aortic valve closure is advanced, and P2 division occurs, and P2 can be hyperthyroidized during pulmonary hypertension.
(2) Left ventricular failure period:
1 diffuse beats can be seen in the anterior region.
2 apical area full systolic miscellaneous sound can be reduced; and P2 can be further advanced.
3 The inner part of the apical area can be heard in the early (early) period.
4 The base of the lungs is fine and wet.
(3) Right heart failure period:
1 Tricuspid valve area can smell 3 ~ 4 / VI systolic hairy murmur.
2 body circulation venous congestion signs:
A. Jugular vein engorgement, pulsation.
B. Liver is large.
C. Positive for jugular venous return.
D. Ascites sign.
E. Lower extremity edema.
Examine
Mitral regurgitation
1, X-ray inspection
Under fluoroscopy, left ventricular pulsation enhancement and left atrial dilatation pulsation can be seen, such as X-ray: the posterior anterior position sees the left atrium, the left ventricle shadow increases; the right atrium shows the double atrium shadow, visible pulmonary congestion, right anterior oblique position Shows that the left atrium expands and the esophagus moves backwards, shifts to the right, and the right ventricle increases in the late stage. When the acute mitral regurgitation is incomplete, the left atrium and left ventricle may be small or only slightly enlarged, mainly manifested as pulmonary edema. Signs.
2, ECG
Mild mitral regurgitation ECG can be normal, moderate to severe left atrial hypertrophy and left ventricular hypertrophy, strain.
3. Echocardiography (UCG)
(1) M-type and two-dimensional UCG: patients with rheumatic valvular disease can be seen with thickening of the valve, chordae, papillary muscle thickening, shortening or prolongation, and the chordae rupture can be seen as "continuous swaying", visible when the leaflet is prolapsed "Hammock-like" changes; systolic mitral valve anterior and posterior dysplasia, and visible gaps, spacing > 2mm, two-dimensional UCG can show the specific location of the closure of the fracture or the leaflet hole, sputum, etc.; indirect signs have left ventricular enlargement The left ventricular outflow tract is widened, the left atrium is enlarged and the atrioventricular ring is expanded.
(2) Doppler UCG: Pulse Doppler detected high-speed, wide-frequency turbulent spectrum in the left atrial side, and color Doppler showed a multicolored mosaic counterflow in the left atrium of the systolic period. The origin and direction of the backflow beam can be displayed.
(3) Quantitative diagnosis: UCG is a semi-quantitative diagnosis of mitral regurgitation, and there are many methods. The clinical application should be comprehensively analyzed:
1 Sampling in the left atrium using pulsed Doppler, according to the length of the retrograde bundle in the left atrium.
2 Using the ratio of the color Doppler flow beam area to the left atrial area to estimate the backflow, the following formula can be used: MR = maximum reflux area / left atrial area, <20% is mild, 20% to 40 % is moderate, 40% to 60% is moderate to severe, and >60% is severe.
3 The blood flow convergence method quantifies the mitral regurgitation, which has been reported at home and abroad, and its clinical value needs further study.
(4) Transesophageal UCG: In addition to the more detailed and accurate observation of the two-dimensional structure of the mitral valve and its attachments (chord, papillary muscle, annulus), the detection rate of atrial thrombus is higher, on the second tip The detection of regurgitation is more sensitive than conventional transthoracic UCG, and it is often possible to detect extremely mild reflux that is not easily found by transthoracic UCG.
(5) Three-dimensional, four-dimensional UCG: can observe the structure and movement of the leaflets in three-dimensional direction, more intuitively observe the starting position, direction and shape of the reflux beam, which is of great help to the diagnosis, and can give the surgical plan Provide more valuable information.
4, left ventricular angiography
Right anterior oblique position and left lateral position. According to the situation of contrast agent appearing in the left atrium during left ventricular angiography, the reflux is divided into 4 levels:
(1) 1/4 degree: The contrast agent reflux beam is not behind the left atrium and is removed when the next ventricle is dilated.
(2) 2/4 degrees: The refluxing contrast agent reaches the posterior wall of the left atrium but does not reach the same gray level as the left ventricle.
(3) 3/4 degrees: The left atrial contrast agent is incremented to the same gray level as the left ventricle.
(4) 4/4 degrees: The contrast agent of the first systolic reflux has reached the entire left atrium, and a contrast agent is visible in the pulmonary vein.
Diagnosis
Diagnosis and diagnosis of mitral regurgitation
diagnosis
According to its clinical manifestations, all the characteristic signs of mitral regurgitation, that is, the apical region has a loud (3/VI), rougher, higher pitch, longer time, full systolic murmur-like murmur with S3; Combined with laboratory tests, especially echocardiography, not only qualitative diagnosis of mitral regurgitation, but also semi-quantitative diagnosis of reflux.
Differential diagnosis
Mitral regurgitation must pay attention to the following differential diagnosis, first of all should be identified as functional or organic mitral regurgitation.
1, functional mitral regurgitation: hypertension, coronary heart disease (papillary muscle dysfunction), primary cardiomyopathy, aortic regurgitation or a large number of left to right shunt (> pulmonary circulation 50%) congenital Heart disease (ventricular septal defect, patent ductus arteriosus) and other diseases, caused by left ventricular or mitral annulus dilatation and relative mitral regurgitation, can be heard louder in the apical region (> level 2 / VI ) The rough systolic murmur, the noise is louder in the case of cardiac insufficiency, and the murmur is reduced after the improvement of cardiac function and the reduction of left ventricle. On the contrary, the systolic murmur of patients with organic mitral regurgitation is relieved during cardiac insufficiency. After the improvement of cardiac function, it is obviously enhanced. The above-mentioned various functional mitral regurgitation patients have their corresponding clinical features and can be identified.
2, organic mitral regurgitation: clinical diagnosis of rheumatic mitral regurgitation, first of all to identify non-rheumatic mitral regurgitation:
(1) mitral valve prolapse: regardless of primary or secondary (cardiomyopathy, coronary heart disease, etc.), due to mucinous degeneration of the mitral or chordae, the valve is hypertrophied, the chordae tendon is prolonged, In the middle of the contraction, due to the excessive chordae, when the mitral valve prolapses to the extreme point, it suddenly tightens, causing the valve to suddenly stop, resulting in a click sound. When the two leaflets are obviously displaced beyond the plane of the annulus, they cannot be normally closed. , can lead to contraction, late reflux murmur, it is also known as "systolic mid-kappy-systolic late murmur syndrome", clinically mild mitral valve prolapse when the apical region only systolic mid-term click When the prolapse is heavier, there is a mid-systolic click sound and a late systolic murmur. When the prolapse is severe, the full systolic murmur appears. At this time, there is usually no click sound. The M-mode echocardiogram is in the middle of the systolic or full systolic period. The leaflet and/or the posterior leaflet closure line (CD segment) is a hammock. "Change", two-dimensional ultrasound shows that the systolic mitral valve leaves one or two leaves to the left atrium, color Doppler can be seen along the prolapsed mitral valve with a regurgitation, while mild prolapse can be no reflux The left ventricular end-diastolic volume reduction factors (such as deep inhalation, three-dimensional, Valsalva action, inhalation of isoamyl nitrite, etc.) can increase the prolapse of the valve leaflets, the click sound is advanced, and the systolic murmur becomes longer. And loud. Conversely, factors that increase the left ventricular end-diastolic volume (such as deep exhalation, squatting, relaxation of Valsalva action, or oral propranolol) can reduce valve leaf prolapse, delaying the sacral period The noise is shortened and reduced.
(2) Partial type of atrioventricular tube malformation: a type of atrioventricular tube malformation. Due to the incomplete development of the endocardial pad during the embryonic period, the primary atrial septum stops growing and fails to fuse with the endocardial pad, resulting in atrial septum. Lower defect and mitral anterior and tricuspid valvular fissures, clinical signs: rough systolic murmur in the apical region, second in the left sternal border, systolic murmur in the pulmonary valve between the three intercostals, with pulmonary artery In the valve area, the second heart sound hyperthyroidism and the fixed second heart sound split, the echocardiogram showed echo loss in the lower part of the interatrial septum, the right atrium, the chamber increased, the left atrium and the chamber increased. The short-axis view of the mitral valve shows the anterior flap fissure. Color Doppler can see the colorful blood flow across the lower part of the interatrial septum into the lower part of the right atrium, and can show reflux blood flow on the atrial side of the second and tricuspid valve.
(3) papillary muscles, chordae rupture: acute myocardial infarction, infective endocarditis, cardiac trauma, etc. can occur nipple tendon rupture, which causes severe mitral regurgitation, clinically in addition to the original disease manifestations Symptoms and signs of acute mitral regurgitation, such as the sudden appearance of rough systolic murmur in the apical region, conduction to the back, and more systolic fine tremor, acute pulmonary edema can occur rapidly after the occurrence of murmur, left atrium Without expansion, echocardiography can detect signs of myocardial infarction and infective endocarditis, as well as the "swinging phenomenon" of the free end of the broken chordae.
3, should be identified as acute or chronic mitral regurgitation.
4, should further judge the degree of mitral regurgitation (semi-quantitative): how much mitral regurgitation, left ventricular function and treatment measures are different, pulse Doppler echocardiography to estimate the mitral regurgitation Method: The sampling volume is between the mitral valve to the left atrium and 1/3 of the left atrium. The reflux spectrum is mild reflux; the reflux spectrum in the heart chamber of the valve from the valve to the left chamber is moderately Flow; if the left atrium can show turbulent flow as severe reflux, color Doppler can estimate the degree of return according to the mitral regurgitation range, direction, time and initial width, etc. The score is used to evaluate the reflux score = mitral regurgitation / left ventricular discharge. When the reflux score is <35%, unless the primary disease progresses, there is no significant effect on left ventricular function. Attention should be paid to the follow-up observation. When the reflux score is >50%, the left heart function can be obviously impaired. Surgical treatment should be considered. 35% to 50% can affect the left heart function. Drug therapy is needed to relieve the mitral valve. Reflux, mitral regurgitation in left ventricular angiography, consistent with color Doppler, such as 1/4 of left ventricular angiography Degree, equivalent to the reflux score <20%, 2/4 degrees is 20% to 40% of the reflux score, 3/4 degrees is 40% to 60% of the reflux score, 4/4 degrees is the opposite >60% of the score.
5, rheumatic mitral regurgitation should pay attention to the following two points in the diagnosis:
(1) Rheumatic mitral stenosis and mitral regurgitation: how to judge whether it is mainly stenosis or insufficiency.
(2) rheumatic mitral stenosis and mitral regurgitation: systolic murmur heard in the apical region, should be associated with rheumatic mitral stenosis and pulmonary hypertension caused by right ventricular hypertrophy, dilatation, caused by the three tips The regurgitation of the valvular insufficiency and the heart's clockwise transposition, the systolic murmur of the tricuspid valve in the lower sternum is translocated to the mitral valve area.
