Nod sign

Introduction Nod sign (Musset sign), can also be called nodding movement. Typical nod signs are seen in severe aortic regurgitation, mainly due to increased pressure difference between the aortic regurgitation and high pulsation of the carotid artery, and regular head-like movements that coincide with the heartbeat. Once the symptoms appear, it quickly causes irreversible left ventricular function changes, even after surgery, the prognosis is relatively poor.

Cause

The nod sign is mainly the symptoms and signs of aortic insufficiency.

Left ventricular diastolic phase in patients with aortic regurgitation undergoes left atrial blood while additionally receiving blood from the aorta, resulting in progressive increase in left ventricular end-diastolic volume, and left ventricular compensatory mechanism with myofibrils , produces eccentric left ventricular hypertrophy, increased left ventricular compliance, gradually adapts to chronic left ventricular chronic volume overload, ensures left ventricular end-diastolic volume increase and left ventricular end-diastolic pressure in the normal range, this myocardial compensation mechanism can be maintained For a long time, the patient is asymptomatic. However, as the disease progresses, the ventricular wall hypertrophy is aggravated. The left heart is mainly in the subendocardial area. With left ventricular systolic and diastolic dysfunction, symptoms appear and the left ventricular dysfunction is irreversible.

Therefore, such patients often fail to see a doctor because of the myocardial compensation mechanism for a long period of time without any symptoms. Once the symptoms appear, it quickly causes irreversible left ventricular function changes, even after surgery, the prognosis is relatively poor. Rheumatic heart disease Aortic valve insufficiency is caused by recurrent rheumatic inflammation, causing inflammation, fibrosis, contracture and deformation of the aortic valve margin, causing aortic valve insufficiency, thickening, fibrosis, calcification, neoplasms, etc. The leaf is closed poorly.

an examination

Related inspection

Electrocardiogram Doppler echocardiography

1. X-ray examination of typical chronic aortic regurgitation has the following performance:

(1) Left ventricular enlargement: the apex is shifted to the left and the apex is enhanced, and the ratio of heart to chest is >0.50.

(2) The ascending aorta is significantly widened: the aortic arch is prominent, with significant pulsation, and the enlarged left ventricle constitutes the "shoe heart".

(3) There may be calcification of the aortic valve or annulus.

(4) Left heart failure often accompanied by enlargement of the left atrium and pulmonary congestion.

2. ECG typically shows left ventricular hypertrophy and strain. Acute aortic regurgitation without left ventricular hypertrophy may have ST-T changes in myocardial ischemia.

3. Echocardiography (UCG)

(1) M-type and two-dimensional UCG: aortic valve leaf thickening, echo enhancement, active stiffness, poor closure of diastolic valve leaflets, visible closure fracture, more than 2 ~ 3mm. The short axis of the aorta clearly shows the structure and movement of the three lobes. When closed, it can show the specific location of the regurgitation and the shape and size of the crevice. The two-dimensional UCG is easier to display when there is sputum or valve leaf prolapse. M-mode can observe rapid tremor of the anterior mitral valve during diastole. The transesophageal UCG (TEE) shows the position and shape of the fissure more clearly, and more sensitively displays the color reflux bundle. Indirect signs: left ventricular enlargement, ventricular septum, left ventricular posterior wall amplitude increased, aortic root widened.

(2) Doppler UCG: sampling under the aortic valve, measurable and diastolic turbulence spectrum. Color Doppler displays a colorful mosaic retroreflective beam on a two-dimensional plane, observing the origin and initial width of the retroreflective beam, and semi-quantitatively based on the area of the retroreflective beam. M-type and two-dimensional UCG are not easy to detect when the incomplete crack is less than 2 mm, and the extremely small backflow beam can be detected very sensitively by spectral Doppler and color Doppler.

(3) Quantitative diagnosis of aortic regurgitation: The severity of aortic regurgitation is estimated based on the size of the distribution of Doppler signals in the left ventricle or the fraction of reflux (RF). According to the reflux fraction, it can be divided into: mild RF <20%, moderate RF 20% to 40%, medium to severe RF 40% to 60%, and severe RF >60%.

4. Cardiac catheterization Left ventricular angiography can measure left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction (EF), left ventricular end-diastolic pressure, and left ventricular wall (ventricular septum, posterior wall) thickness.

5. Ascending aortic angiography can show the shape and size of the reflux, which is valuable for estimating the degree of aortic insufficiency and understanding the pathological processes of the aortic root. According to the contrast of the contrast agent in the left ventricle, the aortic regurgitation is divided into 4 degrees:

(1) 1 degree: The contrast agent only reaches below the aortic valve and is removed by the contraction of the next ventricle.

(2) 2 degrees: The left ventricular contrast agent concentration gradually increased, but still lower than the gray level in the aorta.

(3) 3 degrees: The left ventricular contrast agent gradually increased in gray level to be the same as in the aorta.

(4) 4 degrees: The contrast of the contrast agent in the first diastolic phase is the same as that in the aorta.

Differential diagnosis

Should be differentiated from nodding sputum syndrome.

Intrinsic refers to the occurrence of a strong head-to-head convulsion-like epileptic seizure in infants and young children. Intrinsic mechanism: Intrinsic syndrome is a syndrome that occurs in a variety of underlying diseases. Whether it is hereditary, post-acquired or embryo-acquired, there are brain abnormalities.

According to the medical history, aortic valve area and aortic valve second auscultation area diastolic murmur and peripheral vascular signs, the diagnosis of aortic regurgitation can be made, further according to echocardiography and cardiac catheterization, the aortic valve can be reversed Semi-quantitative diagnosis of the degree of flow and judgment of common causes.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.