An Experimental Study Observing the Transient Expansion of Right Heart During Contrast-enhanced Echocardiography Post Bolus Injection of SonoVueTM / 中国循环杂志

Objectives: To observe the phenomenon of transient expansion of right heart during contrast-enhanced ultrasound (CEUS) by SonoVue?ultrasound contrast agent (UCA) in Chinese experimental mini-pig , and to explore the possible causes of this phenomenon. Methods: 24 healthy Chinese experimental mini-pigs were randomly divided into 3 groups according to the dose of injected contrast agent: 2 ml group (n=8), 1 ml group (n=8) and 0.5 ml group (n=8). Cardiac structure and function at baseline and during contrast procedure were determined by contrast-enhanced echocardiography. Pigs in each group received bolus contrast agent injection followed by 5ml saline flush with baseline concentration, 2, 4 and 6-fold serial dilutions, respectively. When the right heart enlargement appeared, stop the injection and next injection followed after the right heart returned its original size. The study protocols discontinued at the time when the right heart enlargement did not appear post injection. Results: In 2 ml group, the number of right heart enlargement with different injection concentrations was 7, 6, 4, 3, respectively; in 1 ml group, the number of right heart enlargement with different injection concentrations was 6, 5, 3, 1; in 0.5 ml group, the number of right heart enlargement with different injection concentrations was 5, 5, 2, and 0, respectively. Incidence of right heart enlargement decreased in proportion with lower contrast agent amount, and lower contrast concentration(P<0.001). The right heart enlargement phenomenon occurred at about (26±15) s after the injection and lasted for about (47±21) s. Conclusions:Transient expansion of right heart phenomenon is common by bolus injection of contrast agent during CEUS in the Chinese mini-pigs, which may be related to the injected concentration and dosage of the contrast agent, as well as the injection mode and animal species.

Left atrial minimum volume by real-time three-dimensional echocardiography as an indicator of diastolic dysfunction / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Left atrial (LA) maximum volume is becoming a prognostic biomarker for left ventricular (LV) diastolic dysfunction. However, we assessed LV diastolic function by measuring LA phasic volumes using real-time threedimensional echocardiography (RT3DE) in patients with stable coronary artery disease (CAD).</p><p><b>METHODS</b>Sixty-five stable CAD patients with normal LV ejection fraction (LVEF) were divided into three groups according to degree of coronary stenosis: control (n = 15) with <50% stenosis as control group, mildS (n = 25) with mild stenosis (50%-70%) and severeS (n = 25) with >70% stenosis. LA phasic volumes and function were evaluated and compared using RT3DE and two dimensional echocardiography (2DE). N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were examined. The correlations of RT3DE-derived parameters with other conventional indices were analyzed.</p><p><b>RESULTS</b>Significant correlations between RT3DE and 2DE for LA volume measurements were: control, r = 0.93; mildS, r = 0.94; severeS, r = 0.90 (all P < 0.05). Patients with severe coronary stenosis presented higher NT-proBNP level, indices of LA minimum volume and volume before atrial contraction, but lower LA total emptying fraction (LAEF) and LAEFpassive. Significant correlations of RT3DE derived LA volume indices with E/E' (r = 0.695) and NF-proBNP (r = 0.630) level were found.</p><p><b>CONCLUSIONS</b>RT3DE derived, LA indices correlate well with NT-proBNP level and may be superior to 2DE measurements for the evaluation of LV diastolic dysfunction. Enlargement of LA minimum volume in stable CAD patients without systolic dysfunction appears earlier and may be better correlated with LV diastolic function than that of LA maximum volume.</p>

Assessment of the morphology and mechanical function of the left atrial appendage by real-time three-dimensional transesophageal echocardiography / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The left atrial appendage (LAA) is an important source of thrombus formation. We investigated the feasibility of the recently developed real-time three-dimensional transesophageal echocardiography (RT3D-TEE) method in assessment of the morphology and function of the LAA.</p><p><b>METHODS</b>Ninety-six consecutive patients (58 males with a mean age of (43.4 ± 12.5) years) who were referred for 2-dimensional (2D) transesophageal echocardiography (TEE) underwent additional RT3D-TEE. LAA morphology was visualized in multiple views. Orifice size, depth, volumes and ejection fraction (EF) of the LAA, were measured.</p><p><b>RESULTS</b>All the patients underwent RT3D-TEE examination without complications. Ninety-two patients (95.8%) had adequate images for visualization and quantitative analysis of the LAA. The LAA exhibited great variability with respect to relative dimensions and morphology. LAA orifice area was (3.8 ± 1.2) cm(2) with a diameter of (2.4 ± 0.9) cm × (1.4 ± 0.6) cm. The mean depth of the LAA was (2.9 ± 0.7) cm. End-diastolic volume (EDV-LAA), end-systolic volume (ESV-LAA) and EF of the LAA were (6.2 ± 3.7) ml, (4.1 ± 2.8) ml, and 0.35 ± 0.16, respectively. EDV-LAA, ESV-LAA and the orifice area of the LAA in patients with atrial fibrillation (AF) were larger than those without AF, whereas the EF was smaller in the AF patients.</p><p><b>CONCLUSIONS</b>Defining LAA morphology and quantitative analysis of the size and function of the LAA with superior quality and resolution of images using RT3D-TEE is feasible. This technique may be an ideal tool for guidance of the LAA occlusion procedure. Determination of LAA volumes and volume-derived EF by RT3D-TEE provides new insights into the analysis of LAA function.</p>