多普勒超声心动图评估左心室舒张末压的研究

目的探讨多普勒超声心动图评估左室舒张末压的有效方法与指标。方法对６８例病人采用左心导管测压及经胸多普勒超声心动图检测。结果对比研究显示,联合肺静脉与二尖瓣血流频谱分析优于二尖瓣血流频谱分析,肺静脉Ａ峰和二尖瓣Ａ峰时限差值（ＰＡｄ－Ａｄ）与左室舒张末压实测值呈最佳相关性（ｒ＝０．７２,Ｐ＜０．０１）。结论认为应用多普勒超声心动图测定ＰＡｄ与Ａｄ,并以其差值估测左室舒张末压,是一项简便、可靠的无创性评估左室舒张末压的方法。ＰＡｄ－Ａｄ≥０可作为临床判断左室舒张末压增高［≥２．０ｋＰａ（１５ｍｍＨｇ）］的一项半定量指标。     

右室舒张功能的衰老演变规律脉冲多普勒超声心动图研究

目的　检测右室舒张功能的随龄演变规律。方法　用脉冲多普勒超声心动图记录320例健康知识分子的三尖瓣血流频谱,年龄范围26～90岁。结果　右室舒张功能指标Er、EMVr、EDVr、Eir、13FFr、NPFRr、ErAr、随年龄增加分别降低,而EDTcr、Ar、Air、AFFr、随年龄增加而增加。EATcr、EAVr、在各年龄组中无变化。结论　右室的舒张功能年龄增长而减低     

Left ventricular hypertrophy and geometry in a population sample of elderly males

BACKGROUND: Recent studies have shown that left ventricular geometric adaptationto hypertension is complex. The spectrum of geometric adaptationsin a general population and its relationship to systolic anddiastolic function has, however, not been investigated. OBJECTIVES AND METHODS: This echocardiographic and Doppler study investigated the relationshipsbetween left ventricular geometric shape (normal, concentricremodelling, concentric hypertrophy and eccentric hypertrophy)and left ventricular systolic and diastolic function in a populationsample of 584 males aged 70 in Uppsala, Sweden. The influencesof hypertension, coronary heart disease and diabetes mellituswere also evaluated. RESULTS: Sixteen percent of the healthy population (n=167) demonstratedthe presence of left ventricular hypertrophy (mainly eccentric).Subjects with hypertension (n=115) showed an increased leftventricular mass (eccentric left ventricular hypertrophy 31%,concentric left ventricular hypertrophy 15%), when comparedwith healthy subjects (P<0.001). Subjects with coronary heartdisease (n=32) without hypertension also showed an increasedleft ventricular mass (most often eccentric) (P<0.05). UsingDoppler determinations of cardiac index, no differences werefound in cardiac index between the geometric groups. Raisedtotal peripheral resistance, increased blood pressure and enlargedleft atrium were found in both concentric and eccentric leftventricular hypertrophy (P<0.01–0.05). Disturbed diastolicfunction was seen with a prolongation of the isovolumic relaxationtime in eccentric (P<0.01) and increased atrial-dependentleft ventricular filling in concentric left ventricular hypertrophy(P<0.05). CONCLUSIONS: Alterations in left ventricular geometry were common in thispopulation-based study of elderly males, both in healthy subjectsand in subjects with hypertension or coronary heart disease.Raised total peripheral resistance and left ventricular diastolicdysfunction were common findings in both concentric and eccentricleft ventricular hypertrophy.     

Thoracic Aortic Aneurysms: Role of Echocardiography

This article describes the evolving role of echocardiography for the detection and evaluation of thoracic aortic aneurysms. A brief summary of the clinical, anatomical, and pathological features of the etiologic categories of thoracic aneurysms is presented. The advantages and limitations of echocardiography and its comparison with other techniques (computed tomographic scanning, magnetic resonance imaging, and aortography) are discussed.     

Supine Bicycle Exercise Echocardiography: A Potent Immediately Available Tool for Detection and Localization of Myocardial Ischemia for the Initial Cardiologist

Background: Exercise echocardiography (EE) is being used increasingly as an investigative technique now that dynamic images can be captured digitally. Its equivalent reliability with scintigraphic methods has been demonstrated in a hospital setting. This study analyzes its impact on daily practice. Materials and Methods: Standardized progressive stress was produced by supine bicycle ergometry. Echocardiographic images of complete cardiac cycles were obtained in standard apical and parasternal short-axis views before, during, and after maximum effort, and digitized for simultaneous analysis of synchronized images at rest and during exercise. Two hundred sixteen patients (175 men and 41 women; mean age 58 ± 10 years) were studied. Results: Image quality was suboptimal in 4 cases. In the remaining 212 cases, ischemia was detected in 91 cases, and the test was negative in 114 cases and doubtful in 7 cases. Control by selective coronary angiography, as indicated by the clinical situation, was performed in 52 cases. In this particular group, EE showed 87% sensitivity, which is significantly higher than the 59% recorded for conventional exercise testing (P > 0.0001). Conclusions: EE by bicycle ergometer in the supine position is a valid, noninvasive investigative technique that can be used in an outpatient situation (feasibility 95%) since it is readily available. Its value appears to be greatest in cases in which exercise ECG is not conclusive. A negative result enables the initial cardiologist to reassure the patient immediately, which has been demonstrated in the literature to have favorable prognostic value.     

Left Ventricular Thrombus After Pregnancy: Choice of Surgical Access Using Dynamic Three-Dimensional Echocardiography

Two idiopathic thrombi loosely attached to the left ventricular wall were detected by dynamic three-dimensional echocardiography. Because the thrombi were shown to be lobulated and extremly mobile, urgent surgical treatment was mandatory. Three-dimensional image reconstruction enhanced appreciation of left ventricular thrombi by enabling accurate imaging of the spatial relationship between the thrombus, the myocardial wall, and the valvular apparatus, so that the most advantageous surgical access could be chosen.     

Automatic Border Detection to Assess Right Ventricular Function Following Surgical Treatment of Thromboembolic Pulmonary Hypertension

Automatic border detection (ABD) has been developed as a potentially useful means for evaluating ventricular function on line in an automatic fashion. Its success with tracking left ventricular function is established, but little is known about its ability to assess right ventricular (RV) function. Accordingly, 20 patients with severe pulmonary hypertension due to chronic thromboembolic disease underwent standard two-dimensional echocardiography and imaging with ABD before and after pulmonary thromboendarterectomy to correct pulmonary hypertension. ABD-derived results were compared to manually planimetered RV areas calculated from the apical four-chamber view. Doppler tricuspid regurgitant velocity fell significantly with surgery from 4.4 ± 0.6 to 2.9 ± 0.7 m / sec (P < 0.001). The mean values for RV areas derived by manual planimetry and ABD were similar, as was fractional area shortening, which improved significantly with surgery (manual 0.24 ± 0.01 preoperative vs 0.31 ± 0.11 postoperative, P < 0.05; and ABD 0.19 ± 0.05 preoperative vs 0.32 ± 0.15 postoperative, P < 0.001). There was, however, very little correlation between the individual values for ABD versus manually derived RV areas and fractional area shortening, with the best correlation being the RV end-diastolic areas after surgery (y = 0.684x + 7.9, r = 0.564, P = 0.01). These results demonstrate that both manually planimetered RV areas and those determined by ABD can adequately follow changes in ventricular function over time. However, variability within each technique may prevent direct comparison of the absolute values of the two techniques.     

Ultrasound Densitometric Analysis: Comparison Between an Online Digital Acquisition Acoustic Program and an Offline Analog Program

Videodensitometric analysis of myocardial contrast echocardiography is traditionally performed off line. Recently, an online contrast ultrasound analysis system, Acoustic Densitometry (Hewlett-Packard), was introduced. We compared pixel intensities acquired with Acoustic Densitometry to pixel intensities derived from videodensitometry. A tissue phantom was imaged in phase I using three transducer frequencies (2.5, 3.5, and 5.0 MHz). In phase II, an in vitro flowing tube model with various concentrations of Albunex® was imaged at two flow rates, 0.6 and 1.2 m/sec, and at two transducer frequencies, 2.5 and 3.5 MHz. The relationship between pixel intensities yielded by the two systems for identical ultrasound signals was determined with linear regression. Intensities derived with Acoustic Densitometry strongly correlated with those derived from the offline videodensitometry system. The intensities were related by a predictive multiplicative factor based on display characteristics of the two systems. These results suggest that semiquantitative, online perfusion analysis with Acoustic Densitometry is as sensitive as analysis offline with videodensitometry.     

Comparative study of rest technetium-99m sestamibi SPET and low-dose dobutamine stress echocardiography for the early assessment of myocardial viability after acute myocardial infarction: importance of the severity of the infarct-related stenosis

Rest technetium-99m sestamibi single-photon emission tomography (SPET) has been shown to under-estimate viability in some patients with chronic ischaemic myocardial dysfunction. The present study was designed to appraise the value of^99mTc-sestamibi as a viability tracer in patients with a recent myocardial infarction and to determine factors that might influence its accuracy in assessing infarct size. Therefore, rest^99mTc-sestamibi SPET, low-dose dobutamines stress echocardiography and quantitative coronary angiography were performed in 51 patients with a recent myocardial infarction. Perfusion activity and regional wall motion were scored semi-quantitatively using the same segmental division of the left ventricle. Assessment of^99mTc-sestamibi uptake as a marker of viability was performed by comparing a binary uptake score (viable=>50% vs necrotic =50% of the maximal tracer activity) with a binary wall motion classification during low-dose dobutamine infusion (viable=normal/hypokinetic vs necrotic=akinetic/dyskinetic). Infarct size, expressed as the number of segments with evidence of necrotic tissue, was significantly greater in the scintigraphic study than in the echocardiographic study (2.8±1.5 vs 2.2±1.3,P=0.006). This overestimation of infarct size by^99mTc-sestamibi was present only in patients with a severe infarct-related stenosis (% diameter stenosis 65%–100%) and particularly those with late reperfusion therapy (time delay 180 min). In patients without a severe infarct-related stenosis,^99mTc-sestamibi was able to accurately distinguish viable from necrotic segments. Thus, rest^99mTc-sestamibi scintigraphy early after acute myocardial infarction may underestimate residual viability within the infarct region, particularly in patients with low flow state coronary anatomy, as a result of a severe infarct-related stenosis and/or late reperfusion therapy.This paper was presented in part at the European Nuclear Medicine Congress, Brussels, Belgium, August 1995     

Relationship of ambulatory blood pressure monitoring data to echocardiographic findings in haemodialysis patients

BACKGROUND: The present study was performed to assess the value of ambulatoryblood pressure monitoring (ABPM) in determining the adequacyof blood pressure (BP) control, and its relationship to echocardiographicfindings in haemodialysis (HD) patients. METHODS: We studied 40 non-diabetic adult patients who had been on regularHD treatment for a median duration of 43 months. Twenty-four-hourABPM was performed using a non-invasive ABP monitor (Pressurescan,ERKA). Casual BP (cBP) was defined as the average of two measurementsobtained at two HD sessions, one preceding and one followingthe ABP recordings, and was calculated for both the predialysisand postdialysis phases. Two-dimensional and M-mode echocardiographywere performed in each patient to determine interventricularseptal thickness (IVS), left ventricular posterior wall thickness(LVPW), left ventricular fractional shortening (FS), and leftventricular mass index (LVMI) RESULTS: According to average 24-h BP levels, 50% of the patients hadsystolic hypertension (HT) (>139 mmHg), and 72.5% had diastolicHT (>87 mmHg), while only 25% had been diagnosed as HT bycBP measurements (P>0.01 and P>0.0001 respectively). Diurnalvariation in BP was not present in about 80% of the patients.Echocardiography was normal in only four patients (10%). LVMIand LV wall thickness were correlated to ABPM data better thanto cBP measurements. Using stepwise linear regression analysis,LVMI and FVS were positively correlated with systolic BP load(P> 0.0001 and P=0.0001 respectively), and LVPW was positivelycorrelated with night-time systolic BP level (P>0.001). CONCLUSIONS: ABPM is necessary to assess the adequacy of BP control, andis well correlated to end-organ damage of HT in HD patients.