M-mode echocardiography (ME)

M-mode ultrasound (also known as echocardiography) can display the movement of certain organs in the human body, mainly for the diagnosis of cardiovascular diseases. The probe is fixedly facing a certain part of the heart. Due to the regular contraction and relaxation of the heart, the distance between the layers of the heart and the probe changes, and the screen will swing up and down with the beat of the heart. The series highlights, when the scan line moves from left to right at a constant speed, the highlights of the up and down swings are laterally expanded, showing the activity curve of the various layers of the heart during the cardiac cycle, ie, the M-mode echocardiogram. M-mode echocardiography can be used to analyze the trajectory of high-speed motion such as heart wall thickness, velocity, amplitude, slope, and valve. Due to the small amount of information of the single-beam detection structure, it is difficult to fully display the changes in the structure of the heart and the spatial adjacency. With the wide application of two-dimensional echocardiography and other new methods, M echocardiography is no longer used alone in the ultrasound diagnosis of modern cardiovascular disease, but it can still be used as an important auxiliary diagnostic method for a wide range of applications. Basic Information Specialist classification: cardiovascular examination classification: ultrasound Applicable gender: whether men and women apply fasting: not fasting Tips: When you check, relax and cooperate with your doctor. Normal value Left atrial diameter Male 26.77±2.96mm; Female 27.31±2.33mm; Left indoor path End diastolic Male 49.10±9.80mm; Female 43.30±4.20mm; End of contraction Male 28.60 ± 5.20mm; Female 28.80±5.40mm; Right atrial diameter Male 14.0 (6.8 ~ 28.33) mm; Female 13.9 (5.5 to 21.2) mm; Left ventricular outflow tract inner diameter Male 28.6 ± 4.1mm; Female 27.2±3.3mm; Right ventricular outflow tract inner diameter Male 28.9 ± 2.4mm; Female 28.2±2.2mm; Aortic root diameter Male 27.1±2.6mm; Female 26.2±1.9mm; Left ventricular posterior wall thickness contraction Male 14.4±2.0mm; Female 12.3±1.8mm; End diastolic Male 9.1 ± 1.1mm; Female 9.0±1.1mm; Septal thickness Male 9.85 ± 0.30mm; Female 9.32±1.20mm; Right ventricular wall thickness Male 4.4±0.4mm; Female 4.1±0.6mm; Left ventricular posterior wall amplitude Male 12.0 ± 1.6mm; Female 10.8±1.4mm; Aortic root ascending rate Male 41.2 ± 6.6mm / s; Female 34.4 ± 8.9 mm / s; Aortic root descending speed Male 72.0 ± 6.7mm / s; Female 60.3 ± 3.9mm / s; Stroke work index Male 47.2 ± 4.7 ml / m2; Female 45.3±4.8ml/m2; The average value is 46.5±4.87ml/m2; Ejection fraction Male 68±4.8% (0.684±0.048); Female 68.8±4.5% (0.668±0.045); The mean value is 68.5±4.7% (0.685±0.047); The area of ​​the mitral valve mouth is 4-6 cm2; Aortic valve area of ​​2.5 ~ 3.5cm2; The area of ​​the tricuspid valve is 10cm2; The pulmonary valve orifice area is 2.5 to 3.5 cm2. Clinical significance Two-dimensional tissue Doppler images are helpful for displaying wall motion and arrhythmia excitability points. If you can observe the M-type tissue Doppler curve, the sampling line per second is greatly increased, so the wall can be accurately grasped. Cardiac cycle of isovolumic systolic phase ejection, isovolumic diastolic rapid and slow filling period and atrial systole, and other activities in different phases, to understand the differences in the stenosis cross-wall velocity gradient of the heart wall; The sequence of exercise to understand the abnormal excitability of ECG activity in patients with premature ventricular contractions, to determine the ventricular pre-excitation area of ​​patients with pre-excitation syndrome; patients with bundle branch block and pacemaker can find abnormal ventricular Polarized position and time sequence procedures. These data will be of great value in determining the cause of arrhythmia and the location of the pacemaker. High results may be diseases: tricuspid atresia, non-bacterial thrombotic endocarditis, pericarditis, blood pressure, radiation heart damage, hypertensive cardiomyopathy No contraindications, no side effects on the human body. Pay attention to your relaxation and check with your doctor. Inspection process 1. Instrument adjustment method The depth ratio is usually 1:2, and the child is 1:1. The spot scanning time is 4s or 5s, and it needs to be 2s or 2.5s for magnifying observation and 8s or 10s for arc scanning. When ECG, heart sound and heartbeat are applied at the same time, it must be adjusted to the synchronization of the three. 2. Location and general inspection methods As with the two-dimensional echocardiography, a two-dimensional echocardiogram was performed and then converted to an M-mode echocardiogram using a sampling line. 3. Examination methods for various parts of the heart (1) Zone 4 (bottom of the heart) examination method: Zones 4 to 2b are based on the long-axis cross-sectional view of the left ventricle of the left sternum. The sampling line in the 14th zone passes through the aorta and the left atrium, and the anatomical structure is from front to back (the oscillating screen is from top to bottom) for the chest wall and the right anterior wall (no echo of motion), the right ventricular outflow tract, and the aortic root ( Two parallel movement echoes of the anterior wall and the posterior wall, the systolic phase is forward, the diastolic phase is backward, the aortic valve echoes in the aortic cavity, the systolic phase is open, the diastolic phase is closed, and the left atrium and the posterior wall of the left atrium. 2 measurement method and observation content: there is aortic valve echo the standard site of the aortic root. A. Measure the inner diameter of the aortic root end-diastolic phase (refer to the synchronous display of the ECG Q wave at the beginning, the same below), that is, from the upper edge of the aortic root anterior wall echo to the upper edge of the posterior wall echo. Aortic wall thickening or dissection aneurysms should be measured for outer diameter and inner diameter, respectively. B. The amplitude of the aortic valve opening is measured, that is, the vertical distance from the lower edge of the echo of the right coronary valve (upper flap) to the upper edge of the echo without the coronary valve (lower flap). C. Left atrial contraction and end-diastolic diameter, respectively, at the apex of the aortic root forward at the corresponding point of the electrocardiogram T wave and R wave, from the lower edge of the aortic posterior wall to the vertical edge of the echo of the posterior wall of the left atrium distance. 4 Observe the presence or absence of aortic valve echo, multiple reflexes, villous attachments, motion patterns, abnormal echogenicity in the left atrium, echo morphology, size, mobility and left atrial wall and various measurements. (2) Zone 3 (mitral valve) examination 1 The sampling line passes through the anterior mitral valve tip to detect the anterior mitral regurgitation of the "M" shape. The anatomy from front to back is the chest wall and right ventricular anterior wall, right ventricular cavity, ventricular septum, left ventricular outflow tract, anterior mitral lobes, and posterior wall of the left atrium (or transition zone). 2 measurement method and observation content: A. The amplitude of the anterior lobe of the mitral valve: the vertical distance from the upper edge of the mitral curve curve (point C) to the upper edge of the highest point (point E) (the same measurement range is the same). B. Early systolic apex velocity (EF velocity) draws a downward extension along E to F, draws a horizontal line to the right along point E, takes a length of 1 s, and draws a downward sag at the end of the 1 s line. A straight line intersects the EF extension at one point. The length of the vertical line above this point is measured as the EF speed (mm/s). The following is the same as measuring the echo speed. C. Maximum opening speed of the mitral valve, ie DE speed. D. Mitral valve closing speed, ie AC segment speed. E. The peak velocity of the anterior leaflet of the mitral valve, that is, the vertical distance from point A to point C. F. A peak/E peak ratio of the anterior mitral valve, ie A peak amplitude / CE amplitude. G. Left ventricular outflow tract width, distance from the anterior leaflet of the mitral valve to the left ventricular surface of the septum. H. Observe the mitral echo (content with the aortic valve). Note that there is no echo group after the anterior lobe, and there is no villous echo in the left ventricular outflow tract. (3) 2a area (mitral anterior and posterior lobes) examination 1 The sampling line passes through the apex of the anterior and posterior mitral valve. The anterior and posterior anatomy are: chest wall and right ventricular anterior wall, right ventricular cavity, ventricular septum, left ventricular cavity, and anterior and posterior mitral valvular lobes in the left ventricular cavity. Left ventricle posterior wall. 2 Measurement method and observation content: the distance from the E peak to the posterior leaf E peak of the anterior mitral valve, that is, the maximum opening amplitude between the anterior and posterior mitral valves; the distance from the A peak to the A peak, that is, the opening of the mitral valve at the end of diastole The amplitude, such as the CD segment moving toward the left atrium, measures the magnitude of the CD segment motion. Observe the abnormal motion of the anterior and posterior mitral lobes. Such as systolic, diastolic period with or without vibration, the posterior lobe and anterior lobe in the same direction. (4) 2b area (right ventricular, interventricular septum, left ventricle) examination 1 The sampling line passes through the left ventricle showing the mitral chord. The anterior and posterior anatomy are: chest wall and right ventricular anterior wall, right ventricular cavity, ventricular septum, left ventricular cavity (mitral valvular fistula in the left ventricular cavity) The anterior or posterior mitral regurgitation) and the posterior wall of the left ventricle. 2 measurement method and observation content: A. Right internal diameter: The vertical distance from the lower edge of the intima of the right ventricular anterior wall to the lower edge of the right ventricular echo of the ventricular septum was measured. If the compartment is thick, the distance between the anterior wall of the right ventricle and the right ventricular septum should be measured. B. Measurement of interventricular septum: a. Thick diameter, including the thick diameter of the end-diastolic thick-diameter and end-systolic (the ventricular systolic downward movement to the peak), are the vertical distance from the upper edge of the right ventricular echo to the upper edge of the left ventricular echo. The increase rate of systolic thick-diameter can be calculated by the following formula: (thickening period thick-diastolic thick diameter) × 100 / diastolic thick diameter. b. The magnitude of the contraction motion: the magnitude of the downward movement of the diastolic interval to the systolic interval. c. Contraction rate: The rate at which the ventricular contraction systolic moves downwards. C. Left ventricle: a. End diastolic diameter: the end-diastolic period, the vertical distance from the upper edge of the left ventricular echo to the upper edge of the endocardial echo of the left ventricular septum. b. The end-systolic inner diameter, that is, the left ventricular posterior wall systolic forward movement reaches the vertical distance from the upper edge of the endocardial echo to the lower edge of the ventricular septal left ventricular echo. D. Left ventricular posterior wall: a. The amplitude of the systolic movement, that is, the endocardial echo begins to move forward in the systolic phase to the vertical distance to the apex. b. Maximum speed of systole, ie the rate at which the endocardial echo moves forward during systole. c. The maximum speed of movement during diastole, ie the rate at which the endocardium moves from the apex of the forward motion to the posterior motion to the lowest point during the diastolic phase. d. Thick diameter, that is, the distance from the upper edge of the posterior endocardial echo to the upper edge of the epicardial echo in the end diastolic phase. E. The observation content is ventricular septum, left ventricular posterior wall motion pattern, presence or absence of echogenic area in the anterior and posterior pericardial area, and abnormal spatial cloud-like echo group in the left room during diastole, and various measurement data. When the apex of the apex is detected, the left ventricular cavity is small, and only the breech muscle echo is present. The mitral valve and the chordae are not included in the area to observe whether the left ventricle is enlarged or not. (5) Zone 5 (tricuspid) examination method: 1 Based on the long-axis view of the parasternal right ventricular inflow tract, the aortic short-axis map, the parasternal or apical four-cardiogram, the sampling line passes through the tricuspid anterior valve, and the anterior and posterior anatomical structures are: chest wall and right ventricle. Wall, right ventricular cavity, anterior tricuspid valve, right atrium. 2 measurement method and observation content: the same as the measurement site and observation content of the anterior mitral valve. (6) area (pulmonary valve) examination 1 Based on the long-axis view of the parasternal right ventricular outflow tract and the long axis diagram of the pulmonary bifurcation, the sampling line passes through the pulmonary valve. The anterior and posterior anatomy are: chest wall and right ventricular anterior wall, right ventricular outflow tract, and pulmonary valve. 2 measurement method: diastolic e ~ f speed, a wave depth (amplitude) caused by right atrial contraction, pulmonary valve opening speed (b ~ c speed), opening range (b ~ c amplitude). Not suitable for the crowd Inappropriate people: Generally there are no people who are not suitable. Adverse reactions and risks Generally, this examination does not have too many adverse reactions and does not have much influence on the body.

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