| BackgroundHypertrophic cardiomyopathy (HCM) is a familial idiopathic cardiomyopathy of genetic predisposition.The typical pathological changes are the increase of myocardial cells, the disorder of muscle fibers and the interstitial fibrosis in myocardium. Thus the changes result in the increase in stiffness of cardiac muscle, the dysfunction of left ventricular active diastole, the decrease of left ventricular compliance and the reduced left ventricular diastolic function. The reduction of diastolic function occurs earlier than that of systolic function.In some HCM cases, the myocardial systolic function are still of no abnormal changes and can maintain the normal ejection fraction, but there are showing symptoms which can indicate the dysfunction of diastolic function such as the rise in ventricular filling pressure, pulmonary congestion and a series of symptoms caused by diastolic heart failure.At present, heart failure has become the major cause of death in cardiovascular diseases. Therefore, early and accurate evaluation of left ventricular diastolic function of HCM patients is of great significance in treating patients in time and improving the diagnosis apparently.Cardiac catheterization is performed to evaluate the cardiac function as the reliable quantitative technique.However, the invasive approach associated with a minimal and definitive risk of complications limits its clinical application. The parameters of mitral flow spectrum are also vulnerable to the compliance of many factors, so its reliability is affected to a certain extent. Therefore, in recent years how to accurately evaluate of left ventricular diastolic function in a non-invasive way has become a hot topic.Tissue Doppler Imaging(TDI) technique is a new development in non-invasive way to measure the myocardial movement,which can reflect the changes of left ventricular systolic and diastolic function and be not easily influenced by blood flow. Many researches showed that the myocardial velocity in long axis of mitral valve ring could better reflect left ventricular systolic and diastolic function. The ratio (E/E')of the early diastolic mitral valve peak speed (E) and the early diastolic mitral ring peak speed (E') was considered as an index of left ventricular diastolic dysfunction by European heart failure team in 2007, which was already included in the diagnosis standard of diastolic heart failure in 2007. Many studies showed that the technique can accurately measure myocardial movement, and it also can provide a better non-invasive diagnostic method of myocardial dysfunction, which has an important clinical value.At the stages of diastolic heart failure, the increase of left atrial pressure leads to stimulation of sympathetic nerves which increases catecholamine secretion, and then the glomerulusβ1 receptor cells were excited resulting in the increase of renin secretion which can cause myocardial injury.Brain natriuretic peptide (BNP) is directly or indirectly increased in plasma, which may be the neuroendocrine mechanism of BNP increase. In diastolic heart failure, the increased pre-and after load can promote BNP release. The obvious pulmonary congestion in patients can indicate the increase of left ventricular end-diastolic pressure and atrium load, which cause the increase of BNP secretion. Many researches were found to be related to the down-regulation of BNP concentration after treatment,the rates of hospital admission, and the improvement of long-term outcomes. Therefore, it can be used to evaluate the treatment effect of diastolic heart failure by detection of BNP concentration.Objectives1. To probe the presentation of E/E'in HCM patients.2. To observe the changes of E/E'before and after metoprolol is used.Methods From January 2009 to September 2010 in heart center of our hospital,53 cases were admitted by hypertrophic cardiomyopathy through ultrasound, of which 38 cases were male,and 15 cases were female (aged from 29 to 60 years old, the average year was 44±8). The diagnosis standard of ultrasound is:the thickness is beyond 13 mm in left ventricular septal wall or left ventricular posterior wall. The exclusion criteria were secondary myocardial hypertrophy caused by high blood pressure and other cardiovascular diseases and systemic diseases. According to the left ventricular outflow differential pressure(LVPG), the patients were divided into obstructive cardiomyopathy group (16), LVPG≥20 mmHg (1 mmHg= 0.133 kPa) with 10 male cases and 6 female cases, which aged from 29-58,with an average year of 43±9; In the non-obstructive cardiomyopathy group, LVPG< 20 mmHg (1 mmHg=0.133 kPa), 28 cases were male,9 cases were female, aged from 31 to 60 years old, with an average years of 45±6. Among them,28 cases of HCM patients (9 cases of obstruction and 19 cases of non-obstruction) received metoprolol drug treatment; 25 cases HCM patients (7 cases of obstruction and 18 cases of non-obstructive) received perindopril combined with metoprolol treatment. The control group was consisted of 50 cases from medical center,with 28 male cases and 22 female cases which aged from 26-56 years with an average years of 41±9. The cardiopulmonary and other diseases were excluded by interrogation, physical examination, blood pressure measurement, electrocardiogram, ultrasound and chest radiograph. The 3 ml venous, add EDTA100ul, were collected blood in the early morning before and after treatment, then centrifuged by 2000 r/min,15 min, and the plasma was placed in-20℃, used for the detection of BNP. The early diastolic peak speed of mitral valve E and early diastolic peak speed of mitral ring E'(E/E') were measured before and after treatment. All of the data were presented as the means±S.E. A single cell was defined as one unit. One-way ANOVA with repeated measures and analysis of variance were used for statistical analysis. Statistical analysis was performed using the SPSS 10.0 software, and P< 0.05 was considered to be statistically significant.Results1. Compared with the normal control group, the early diastolic peak velocity of HCM was significantly reduced. The late diastolic peak velocity significantly increased, and the ratio of early diastolic peak velocity and the late diastolic peak velocity significantly reduced. The ratio of E/E' ratio increased significantly, and the incidence of E/E'> 15 is the highest;2. Plasma BNP levels improved significantly after 12 months of metoprolol treatment (P< 0.05); BNP significantly reduced after 6 months of Metoprolol and perindopril treatment (P< 0.05), it was further reduced after 12 months (P< 0.05);3. After 1 year of metoprolol and perindopril treatment, left ventricular outflow pressure and E'/A' improved significantly (P< 0.05); E/E' significantly reduced after 1 year of metoprolol treatment (P< 0.05), E/E' significantly reduced after 6 months of Metoprolol and perindopril treatment (P< 0.05), it was further reduced after 12 months (P< 0.05).4. Compared with the control group, the levels of plasma BNP in obstructive cardiomyopathy and non-obstructive cardiomyopathy groups increased significantly (P< 0.05); In contrast with the non-obstructive cardiomyopathy, plasma BNP levels of obstructive cardiomyopathy also increased significantly (P < 0.05).Conclusion1. The E/E' combined with the level of plasma BNP can efficiently detect the left ventricular diastolic function.2. The E/E' combined with the level of plasma BNP can objectively evaluate the changes of left ventricular diastolic function of HCM. |
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