实时三维超声心动图在肥厚型心肌病中的应用价值

目的探讨实时三维超声心动图(RT-3DE)在肥厚型心肌病(HCM)患者中的应用价值。方法选取肥厚型心肌病患者42例,另选健康体检者40名为对照组。全容量实时三维显示(full-volume),启动切割键(crop)对图像进行切割后,观察心腔立体形态及二尖瓣叶收缩期前向运动(SAM)现象,并将图像存储后于TomTec工作站进行分析。结果应用RT-3DE能清晰显示HCM患者心腔立体空间结构及SAM现象,并可以准确测量左心室舒张末容积(EDV)、收缩末容积(ESV)、每搏量(SV)和左心室射血分数(LVEF)等指标,结果显示:HCM组EDV(70.8±15.2)ml,SV(46.2±8.1)ml,与对照组比较均减低(均为P0.01),ESV(26.0±8.2)ml,EF64.4%±6.4%,与对照组比较差异无统计学意义(均为P0.05)。结论应用RT-3DE能够反映HCM患者心脏的立体空间结构,确定二尖瓣前叶运动与左心室流出道梗阻的关系,是准确评价HCM患者左心室收缩功能的方法。     

Tako-tsubo cardiomyopathy

A 48-year-old woman presented to her local hospital with chest pain. Her electrocardiogram showed incomplete right bundle branch block, diffuse ST segment elevation and QTc prolongation. Shortly after admission, she became hypotensive and was referred for a coronary angiogram. Her coronary arteries were normal, but left ventriculography showed morphological changes typical of apical ballooning, as found in tako-tsubo cardiomyopathy. An echocardiogram confirmed complete akinesis of the left ventricular apex, with hyperkinesis of basal segments and an ejection fraction of 35% to 40%. Dynamic left ventricular outflow tract obstruction was also noted. After temporary support with intra-aortic balloon counterpulsation, fluids and noradrenaline, she recovered promptly. The present paper reviews the characteristic features of tako-tsubo cardiomyopathy.     

Intraventricular dyssynchrony assessment by real-time three-dimensional echocardiography

Heart failure is exceedingly prevalent in the United States and in other developed countries. Treatment regimens are complex and now include electrical therapy. Methods for evaluating left ventricular dyssynchrony using echocardiography rather than QRS duration have been developed, with tissue Doppler velocity parameters being the most popular. Real-time three-dimensional echocardiography is another novel method for dyssynchrony evaluation that has potential advantages over existing techniques. The authors describe their experience with three-dimensional echocardiography dyssynchrony evaluation and offer insights into the direction that this technology must move to improve results.     

Usefulness of real-time three-dimensional echocardiography for evaluation of myectomy in patients with hypertrophic cardiomyopathy

Real-time 3-dimensional echocardiography was performed in 10 patients with obstructive hypertrophic cardiomyopathy (HC) before and after myectomy and in 6 controls. The exact location of systolic anterior motion of the mitral leaflet was shown in all patients with HC with a predominant involvement of the medial portion in 4 patients and the middle portion in 6 patients. The smallest area of the left ventricular outflow tract was significantly smaller in patients with HC than in controls (1.4 +/- 0.7 vs 5.1 +/- 1.2 cm(2), p <0.01), significantly increased after myectomy (4.8 +/- 1.8 cm2, p <0.01) and was associated with a reduction of the pressure gradient at rest from 63 +/- 41 to 15 +/- 5 mm Hg (p <0.01).     

Initial clinical experience of real-time three-dimensional echocardiography in patients with ischemic and idiopathic dilated cardiomyopathy

The geometry of the left ventricle in patients with cardiomyopathy is often sub-optimal for 2-dimensional ultrasound when assessing left ventricular (LV) function and localized abnormalities such as a ventricular aneurysm. The aim of this study was to report the initial experience of real-time 3-D echocardiography for evaluating patients with cardiomyopathy. A total of 34 patients were evaluated with the real-time 3D method in the operating room (n = 15) and in the echocardiographic laboratory (n = 19). Thirteen of 28 patients with cardiomyopathy and 6 other subjects with normal LV function were evaluated by both real-time 3-D echocardiography and magnetic resonance imaging (MRI) for obtaining LV volumes and ejection fractions for comparison. There were close relations and agreements for LV volumes (r = 0.98, p <0.0001, mean difference = -15 +/- 81 ml) and ejection fractions (r = 0.97, p <0.0001, mean difference = 0.001 +/- 0.04) between the real-time 3D method and MRI when 3 cardiomyopathy cases with marked LV dilatation (LV end-diastolic volume >450 ml by MRI) were excluded. In these 3 patients, 3D echocardiography significantly underestimated the LV volumes due to difficulties with imaging the entire LV in a 60 degrees x 60 degrees pyramidal volume. The new real-time 3D echocardiography is feasible in patients with cardiomyopathy and may provide a faster and lower cost alternative to MRI for evaluating cardiac function in patients.     

Interventional three-dimensional echocardiography: using real-time three-dimensional echocardiography to guide and evaluate intracardiac therapies

Real-time three-dimensional echocardiography (RT3DE) already has demonstrated its utility in guiding intracardiac procedures. This article discusses the advantages RT3DE has over the previous standard of 2D echocardiography.     

Tako-tsubo cardiomyopathy after automobile accident

A 53-year-old woman was involved in a traffic accident while driving her car. She had chest oppressive sensation 6 h after the accident, and was admitted to our hospital. On admission, she had no external injury. She was fully conscious, and felt anxiety about the accident. Twelve-lead electrocardiogram showed mild ST-segment elevation in leads II, III, aVF and V2-5. Chest X-ray did not show pneumothorax, rib fracture or pulmonary congestion. Emergency coronary angiography showed no significant coronary artery disease. However, left ventriculography showed akinesia of the mid-to-distal portion of the left ventricular chamber and hyperkinesia of the basal portion (ejection fraction=45%). She was diagnosed as having tako-tsubo cardiomyopathy. Follow-up left ventriculography 11 days later showed normal wall motion of the left ventricular chamber (ejection fraction=62%). Clinicians should recognize that tako-tsubo cardiomyopathy is one of etiologies of chest symptom after automobile accident. It can occur due to emotional stress even if patients have no external injury.     

Improved assessment of mitral valve stenosis by volumetric real-time three-dimensional echocardiography

OBJECTIVES: This study was performed to determine the feasibility, accuracy and reproducibility of real-time volumetric three-dimensional echocardiography (3-D echo) for the estimation of mitral valve area in patients with mitral valve stenosis. BACKGROUND: Planimetry of the mitral valve area (MVA) by two-dimensional echocardiography (2-D echo) requires a favorable parasternal acoustic window and depends on operator skill. Transthoracic volumetric 3-D echo allows reconstruction of multiple 2-D planes in any desired orientation and is not limited to parasternal acquisition, and could thus enhance the accuracy and feasibility of calculating MVA. METHODS: In 48 patients with mitral stenosis (40 women; mean age 61 +/- 13 years) MVA was determined by planimetry using volumetric 3-D echo and compared with measurements obtained by 2-D echo and Doppler pressure half-time (PHT). All measurements were performed by two independent observers. Volumetric data were acquired from an apical view. RESULTS: Although 2-D echo allowed planimetry of the mitral valve in 43 of 48 patients (89%), calculation of the MVA was possible in all patients when 3-D echo was used. Mitral valve area by 3-D echo correlated well with MVA by 2-D echo (r = 0.93, mean difference, 0.09 +/- 0.14 cm2) and by PHT (r = 0.87, mean difference, 0.16 +/- 0.19 cm2). Interobserver variability was significantly less for 3-D echo than for 2-D echo (SD 0.08cm2 versus SD 0.23cm2, p < 0.001). Furthermore, it was much easier and faster to define the image plane with the smallest orifice area when 3-D echo was used. CONCLUSIONS: Transthoracic real-time volumetric 3-D echo provides accurate and highly reproducible measurements of mitral valve area and can easily be performed from an apical approach.