Evaluation of left atrial function and its determinants by three-dimensional echocardiography in patients with hypertrophic cardiomyopathy / 中华医学超声杂志（电子版）

Objective To evaluate the left atrial function and to explore its determinants in patients with hypertrophic cardiomyopathy by three-dimensional echocardiography (3DE).Methods 46 patients with HCM (obstructive HCM:25 cases,nonobstructive HCM:21 cases) and 46 healthy cases (controls) were enrolled in this study.Time-volume curve of left atrium was acquired by 3DE in all subjects.Left atrial maximal volume (LAVmax),left atrial minimal volume (LAVmin) and left atrial presystolic volume (LAVp) were acquaired.Left atrial volume index (LAVI),left atrial expansion index (LAEI),left atrium emptying fraction (LAEF),left atrium passive emptying fraction (LAPEF) and 1eft atrium active emptying fraction (LAAEF) were calculated.Comparative analysis between two groups was taken .The Spearman correlation analysis and multiple linear regression analysis between left atrial volume index (LAVI) with interventricular septal thickness (IVSd),left ventricular outflow tract peak gradient (LVOT-PG),mitral regurgitation (MI), left ventricular diastolic function (LVDF) were analyzed respectively .Results Compared to the controls LAVmax (45.67 ±11.96)ml,LAVmin (20.48 ±6.80)ml,LAVp (24.48 ±9.31)ml,LAVI 25.63 ±6.52, LAEI (1.32 ±0.49)%,LAEF (55.25 ±8.06)%,LAPEF (35.90 ±7.00)%and LAAEF (30.20 ±10.13)%, the patient with HCM had a significantly larger LAVmax (81.45 ±24.24)ml,LAVmin (44.60 ±18.96)ml, LAVp (61.00 ±21.64) ml and LAVI 45.39 ±14.17,there were significant differences among the groups (t=8.978,8.123,9.227,8.436,all P0.01).There were significant positive correlation between LAVI and IVSd,LVOT-PG,MI,LVDF respectively (r=0.704,0.517,0.640,0.701,all P<0.01).Multiple linear regression analysis demonstrated that IVSd , LVOT-PG, MI and LVDF were correlated factors of LAVI (absolute standardized coeffients =0.264,0.515,0.614,0.341,all P<0.05).Conclusions 3DE could evaluate the left atrial volume and function in patients with HCM , with increased left atrial volume and decreased reservioer,conduit and booster pump function .Mitral regurgitation,obstruction of left ventricular outflow tract,left ventricular diastolic dysfunction and the thickness of left ventricular wall contributed to left atrial dysfunction at different levels ,among which mitrial regurgitation contributed the most .

Impact of age and gender on cardiac structure and function in normal Chinese population / 中华心血管病杂志

<p><b>OBJECTIVE</b>To identify the impact of age and gender on cardiac structure and left ventricular function in normal Chinese by echocardiography.</p><p><b>METHODS</b>Cardiac structure, valve flow velocity and cardiac function were measured by echocardiography in 15,692 healthy volunteers. Subjects were grouped by age at 5 years interval in population older than 5 years. Children under 5 years were divided into 3 age groups (< 1 years, 1 - 3 years, 4 - 5 years). Hierarchical cluster analyses were performed for ages, based on indexes of cardiac structure and function respectively.</p><p><b>RESULTS</b>Six groups (< 1 years, 1 - 3 years, 4 - 5 years, 6 - 10 years, 11 - 20 years, > or = 21 years) were generated after the age hierarchical cluster analyses based on index of cardiac structure. Four groups (< or = 30 years, 31 - 50 years, 51 - 80 years, > or = 81 years) were generated based on spectral current flow. Six groups (< 1 years, 1 - 3 years, 4 - 5 years, 6 - 10 years, 11 - 15 years, > or = 16 years) were generated based on left ventricular systolic function and five groups (< or = 15 years, 16 - 30 years, 31 - 50 years, 51 - 80 years, > or = 81 years) were generated based on left ventricular diastolic function. Cardiac structure index were similar between male and female in age groups < or = 10 years and significantly lower in females than males in age groups > or = 11 years (P < 0.05). Valve flow velocity was similar between male and female in various age groups (P > 0.05). Left ventricular systolic function was similar between male and female in age groups < or = 10 years but was significantly higher in males than females in age groups > or = 11 years (all P < 0.05). Left ventricular diastolic function was similar between female and male in various age groups (P > 0.05) and equally decreased with aging in both female and male subjects.</p><p><b>CONCLUSIONS</b>The cardiac development in Chinese population can be divided in 6 phases and becomes stable in subjects older than 21 years, left ventricular systolic function becomes stable in subjects older than 16 years and the left ventricular diastolic function declines physiologically with aging.</p>

Dobutamine stress echocardiography in patients with hypertrophic cardiomyopathy / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the safety and efficiency of the dobutamine stress echocardiography in patients with hypertrophic cardiomyopathy and estimate the difference between provokable obstruction and resting obstruction in these patients.</p><p><b>METHODS</b>Echocardiography was performed in 22 patients with HCM (LVOTPG < 50 mm Hg at rest, 1 mm Hg = 0.133 kPa) at rest and at the end point of dobutamine stress. Dobutamine was administered via an infusion pump, starting at a dose of 5 microg x min(-1) x kg(-1) and increasing every 5 minutes by 5 microg x min(-1) x kg(-1) till the maximum dose of 20 microg x min(-1) x kg(-1). Fifty-seven patients with HCM (LVOTPG > 50 mm Hg at rest) were also studied at rest.</p><p><b>RESULTS</b>In these 22 patients, the mean maximum velocity of LVOT was 5.39 +/- 1.60 m/s, the mean maximum LVOTPG was 125.7 +/- 62.4 mm Hg at the end point of dobutamine stress and the mean dose of dobutamine was 13.90 +/- 6.85 microg x min(-1)xkg(-1). Sixteen patients evidenced positive stress results at the end point of dobutamine stress. The main difference between the provokable obstruction and resting obstruction was that in provokable obstruction patients, the SAM positive patients were fewer and the proportion of Maron II patients was higher (50%).</p><p><b>CONCLUSIONS</b>Dobutamine stress echocardiography was a safe and sensitive way for detecting patients with hypertrophic cardiomyopathy. Provokable obstruction patients had fewer SAM and higher proportion of Maron II.</p>

Comparable effects of percutaneous transluminal septal myocardial ablation and subaortic ventriculotomy in treating patients with hypertrophic obstructive cardiomyopathy, an echocardiography follow-up study / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare the effect of percutaneous transluminal septal myocardial ablation (n = 20) with subaortic ventriculotomy (n = 17) in patients with hypertrophic obstructive cardiomyopathy by echocardiography.</p><p><b>METHODS</b>The pre- and post-operation (1 week post procedure) gradients of left ventricular out flow (LVOTGs) were measured by echocardiography.</p><p><b>RESULTS</b>Post operation LVOTGs were significantly reduced than that of pre-operation in patients treated with either percutaneous transluminal septal myocardial ablation [(36 +/- 20) vs. (99 +/- 19) mm Hg (1 mm Hg = 0.133 kPa), P < 0.05], or subaortic ventriculotomy [(28 +/- 17) vs. (117 +/- 32) mm Hg]. Post operation LVOTGs were also similar with the two procedures [(36 +/- 20) vs. (28 +/- 17) mm Hg, P > 0.05].</p><p><b>CONCLUSION</b>Percutaneous transluminal septal myocardial ablation is as effective as subaortic ventriculotomy in treating patients with hypertrophic obstructive cardiomyopathy.</p>

Assessment of diastolic function in patients with hypertrophic cardiomyopathy by Doppler tissue imaging / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To determine the clinical application of pulsed Doppler tissue imaging in assessing the left ventricular diastolic function and in discriminating between normal subjects and patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction.</p><p><b>METHODS</b>We measured the peak diastolic velocities of mitral annulus in 81 patients with hypertrophic cardiomyopathy with various stages of diastolic dysfunction and 50 normal volunteers by Doppler tissue imaging using the apical window at 2-chamber and long apical views, respectively. The myocardial velocities were determined with use of variance F statistical analysis.</p><p><b>RESULTS</b>Early diastolic myocardial velocities of mitral annulus were higher in normal subjects than in patients with hypertrophic cardiomyopathy with either delayed relaxation, pseudonormal filling, or restrictive filling. However, peak myocardial velocities of mitral annulus during atrial contraction were similar in normal subjects and patients with hypertrophic cardiomyopathy.</p><p><b>CONCLUSION</b>Doppler tissue imaging can directly reflect upon left diastolic ventricular function. Early phase of diastole was the best discriminator between control subjects and patients with hypertrophic cardiomyopathy.</p>