What Is Systolic Dysfunction?

It is caused by evaporation of water. The shrinkage process can be divided into two stages: the first stage (AB) indicates that the reduction of soil volume is proportional to the decrease of water content, which is in a linear relationship; the reduced volume of soil is equal to the volume lost by water dispersion; the second stage (BC) shows that the decrease in soil volume is in a curve with the decrease in water content. The reduction of soil volume is less than the loss of water volume. As the water content decreases, the soil volume shrinks more and more slowly.

Contractility

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Polysemous entry, there are two different interpretations. Contractile heart failure

It is caused by evaporation of water. The shrinkage process can be divided into two stages: the first stage (AB) indicates that the reduction of soil volume is proportional to the decrease of water content, which is in a linear relationship; the reduced volume of soil is equal to the volume of water lost; (BC) shows that the decrease in soil volume is in a curve with the decrease in water content. The reduction of soil volume is less than the loss of water volume. As the water content decreases, the soil volume shrinks more and more slowly.

If the volume change and the dehydration volume are extrapolated to the Y axis in a straight line, then CE is the pore volume occupied by air; EO is the volume of the solid particles, and the extension of the horizontal line from point C to AB is D, then D The moisture content of the point is the shrinkage limit WS.

When the moisture content in the soil is less than the shrinkage limit WS, the soil volume shrinks extremely; as the moisture content increases, the soil volume increases. When the moisture content exceeds the liquid limit, the soil collapses.

Contractive clinical manifestations are

(1) Left ventricle enlargement, left ventricular end-systolic volume increase, and lvef40%. (2) Have a history, symptoms and signs of basic heart disease. (3) with or without symptoms of dyspnea, fatigue, and fluid retention (edema).

1. Based on medical history and physical examination, provide clues to the cause of various heart diseases, such as coronary heart disease, heart valve disease, hypertension, cardiomyopathy and congenital heart disease. Judging left heart failure, right heart failure or total heart failure based on clinical symptoms and signs.

2. Two-dimensional echocardiography (2de) and Doppler ultrasound: (1) diagnosis of pericardial, myocardial or heart valve disease. (2) Quantitative or qualitative atrioventricular diameter, cardiac geometry, wall thickness, wall motion, pericardium, valve and vascular structure, valvular stenosis quantification, degree of insufficiency, measurement of lvef, left ventricular end-diastolic volume (lvedv), and contraction Terminal capacity (lvesv). (3) The difference between diastolic dysfunction and systolic dysfunction, lvef <40% is left ventricular systolic dysfunction. lvef can also identify heart failure caused by systolic insufficiency or other causes. (4) lvef and lvesv are the most valuable indicators for judging systolic function and prognosis. In patients with coronary heart disease with a left ventricular end-systolic volume index (lvesvi = lvesv / body surface area) of 45 ml / m2, the mortality rate tripled. (5) Provide objective indicators for evaluating the effect of treatment.

When the left ventricle is enlarged, spherical, and the short diameter of the left ventricle is greater than 1/2 of the long diameter, the left ventricular volume and lvef are clearly calculated by the vertical method through the measurement of the left ventricular short diameter of m-mode echocardiography. In particular, when segmental wall motion abnormalities are present, m-cardiac echocardiographic measurements will produce errors, so it is recommended to use 2de's modified simpson method to measure left ventricular volume and lvef. Compared with angiography or autopsy, 2de has better correlation with left ventricular volume measurement and lvef, but the acquisition of accurate data depends on the sharpness of the intima of the ventricular image and requires good repeatability. In some elderly, obese and emphysema patients, it is difficult to obtain satisfactory 2de images, so the clinical application is limited. Because ultrasound is simple, inexpensive, and convenient for bedside and repeated examinations, 2de is the most common measure of left ventricular function.

3 Radionuclide ventricle angiography and radionuclide myocardial perfusion imaging: Radionuclide ventricle angiography can accurately measure left ventricular volume, lvef, and wall motion. Radionuclide myocardial perfusion imaging can diagnose myocardial ischemia and myocardial infarction, and is helpful to distinguish dilated cardiomyopathy and ischemic cardiomyopathy.

4 X-ray chest radiograph: Provides information on enlarged heart, pulmonary congestion, pulmonary edema, and existing lung diseases.

5. ECG: Provides information on previous myocardial infarction, left ventricular hypertrophy, extensive myocardial damage, and arrhythmia.

6. Coronary angiography: Patients with angina pectoris or previous myocardial infarction who need vascular reconstruction or patients with clinically suspected coronary heart disease should undergo coronary angiography. It can also identify ischemic and non-ischemic cardiomyopathy. However, coronary angiography cannot judge viable myocardium, and the assessment of viable myocardium is essential for the necessity of revascularization in patients with old myocardial infarction. In patients with myocardial survival, revascularization can effectively improve left ventricular function.

7. The methods currently used in clinical judgment of viable myocardium are: (1) Low-dose dobutamine echocardiography stress test (dse) that stimulates myocardial contractility reserve. (2) Radionuclide myocardial perfusion imaging (201t1 and 99mtc-mibispect) and metabolic tracer fluorodeoxyglucose (fdg) to determine myocardial activity by positron emission tomography (PET).

The clinical application value of low-dose dobutamine echocardiography stress test to evaluate surviving myocardium has been recognized clinically, and the sensitivity to diagnose surviving myocardium is 80% to 85%, and the specificity is 85%. Because the method is simple, safe, and inexpensive, it can be used as the method of choice for assessing viable myocardium. 201t1 reperfusion myocardial imaging is a more reliable method for evaluating surviving myocardium. Nitrate 99mtc-mibi myocardial imaging can improve the accuracy of evaluating surviving myocardium. The sensitivity of radionuclide to diagnose myocardial viability is 90% and the specificity is 70%. Pet perfusion and metabolic imaging are the most reliable non-invasive methods for evaluating surviving myocardium, but they are expensive and technically complex, and currently cannot be used as a routine inspection method.

8. Myocardial biopsy: The diagnostic value of cardiomyopathy of unknown origin is limited, which helps to clarify the diagnosis of inflammatory or invasive myocardial disease.

Systolic cardiac insufficiency

1. NYHA heart function classification: Grade : No symptoms of heart failure in daily activities. Grade : Heart failure symptoms (dyspnea, fatigue) in daily activities. Grade III: Symptoms of heart failure below daily activities. Grade IV: Symptoms of heart failure at rest. The lvef and heart function grading symptoms in patients with heart failure are not completely consistent.

2.6 minute walking test: Under specific circumstances, measure the distance walked within a specified time. Although the walking distance of patients with heart failure within 6 minutes may be affected by the physician's induction or the subjective initiative of the patient, this method is safe, simple, and easy to implement, and has been gradually applied in clinical practice. The 6-minute walking distance can not only assess the patient's exercise endurance, but also predict the patient's prognosis. The solvd (studiesofleftventricu1ardysfunction) test subgroup analysis showed that compared with patients with short 6-minute walking distance and long distance, during the 8-month follow-up period, the former was 10.23% and the latter was 2.99% (p = 0.01); The hospitalization rate of heart failure was 22.16% in the former and 1.99% in the latter (p <0.0001), suggesting that patients with short 6-minute walking distance had a poor prognosis.

Contractile fluid retention

The patient's weight should be recorded at each follow-up visit, pay attention to the degree of jugular vein filling and hepatic jugular vein reflux signs, and pay attention to the degree of lung and liver congestion (pulmonary rales, hepatomegaly). Abdominal mobility is monotonic to detect ascites. The determination of fluid retention is very important to determine whether diuretic therapy is needed. Weight gain in a short period of time is a reliable indicator of fluid retention. Therefore, weight measurement is a useful method to determine fluid retention.

Evaluation of other physiological functions of contractility

Invasive hemodynamic tests are used primarily for severely life-threatening conditions and for the treatment of unresponsive pump failure or when differential diagnosis of dyspnea and hypotension shock is needed. When there is arrhythmia, a 24-hour dynamic electrocardiogram record can be made.