Diagnostic performance of cardiac computed tomography versus transesophageal echocardiography in infective endocarditis: A contemporary comparative meta-analysis

ObjectiveTo compare the diagnostic accuracy of transesophageal echocardiography (TEE) and cardiac computed tomography (CCT) in diagnosing infective endocarditis (IE).BackgroundTEE is a mainstay imaging modality for IE, while the use of CCT is becoming increasingly prevalent. Data directly comparing the diagnostic performance of these two imaging modalities for IE are limited.MethodsWe conducted a systematic review and meta-analysis of published literature in Embase, PubMed and Cochrane databases through October 1, 2020 for studies comparing diagnostic performance of CCT and TEE for the diagnosis of IE in the same patient populations. A meta-analysis of diagnostic accuracy was performed using the bivariate model based on studies that used surgical pathology as a reference standard for defining endocarditis. From a total of 10 studies included in the meta-analysis, a total of 872 patients were evaluated.ResultsThe pooled sensitivities and specificities of TEE for detecting vegetations were 96% and 83% respectively, whereas for CCT, they were 85% and 84%, respectively. In the prosthetic valve sub-group, the pooled sensitivities and specificities of TEE for detecting vegetations were 89% and 74% respectively, whereas for CCT, they were 78% and 94%, with CCT being more specific than TEE (p < 0.05). The pooled sensitivities and specificities of TEE for detecting periannular complications were 70% and 96% respectively, whereas for CCT, they were 88% and 93%, respectively. CCT showed a trend (p = 0.06) towards higher sensitivity than TEE for detection of periannular complications. The pooled sensitivities and specificities of TEE for detecting leaflet perforation were 79% and 93% respectively, whereas for CCT, they were 48% and 93% respectively, with TEE being more sensitive (p < 0.05). The two modalities also showed comparable diagnostic performance for detecting fistulae, paravalvular leaks and prosthetic valve dehiscence.ConclusionIn a contemporary comparative meta-analysis, TEE and CCT demonstrated both good diagnostic accuracy for detecting valvular involvement and complications of IE. TEE performed better for detecting leaflet defects, whereas CCT performed better in cases of prosthetic valve involvement, and showed a trend towards improved detection of periannular complications. Appropriate, complementary use of both TEE and CCT in a multimodality imaging approach in clinical practice may achieve the highest diagnostic performance.     

Dynamic right ventricular outflow obstruction: A rare cause of hypotension during anestesia induction

IntroductionDynamic obstruction of right ventricle outflow tract (RVOTO) is a rare condition that may acutely cause severe heart failure. It has been reported in some hypertrophic cardiomyopathies, after lung transplantation, and in some cases of hemodynamic instability after cardiopulmonary bypass.Presentation of caseWe report the case of a 71-year-old man who developed severe hypotension during the induction of general anesthesia for surgical coronary revascularization. Hypotension did not respond to the initial treatment with vasoconstrictors and fluids. RVOTO was suspected during pulmonary artery catheterization because of the difficulty of the catheter tip to move from the right ventricle to the pulmonary artery and, successively, because of the finding of a large gradient between the systolic pressure in the right ventricle and in the pulmonary artery. The diagnosis was confirmed by transesophageal echocardiogram (TEE). Hemodynamics recovered after the infusion of cristalloids, 1 L, and the suspension of vasoconstrictors and inotropes.DiscussionThis is the first case in which RVOTO was observed during the induction of general anesthesia. Although this is a rare condition, the diagnostic suspect is of outmost importance because treatment is mainly based on fluid administration, and drugs with positive inotropic properties (like most vasoconstrictors) are contraindicated.ConclusionsRVOTO is an unusual, but possible cause of severe arterial hypotension during general anesthesia induction. TEE is useful for the evaluation of severely hypotensive patients who do not respond to routine treatment with fluids and vasoconstrictors.     

经食管超声心动图对窦性心律时右心耳血流频谱的研究

目的　应用经食管超声心动图技术 (TEE)观察窦性心律时右心耳结构、功能和血流频谱的特点。方法　选取 2 6例窦性心律患者 ,常规超声资料的留取后 ,采用经食管超声心动图技术 ,清楚显示右心耳图像并采集血流频谱。结果　窦性心律时右心耳血流频谱形态可分为 4相、 3相和 2相波 ,在获取的 2 6例图像中 ,右心耳血流频谱为 4相波者有 6例(2 3% ) ,为 3相波者有 12例 (4 6 % ) ,为 2相波者有 8例 (31% )。结论　窦性心律时右心耳血流频谱是反映右心房和右心耳功能的良好指标     

可视化心脏在多平面经食管超声心动图诊断房间隔缺损中的应用价值

目的　探讨多平面经食管超声心动图( TEE)诊断房间隔缺损的最佳显示方位和切面。方法　将可视化心脏与多平面TEE进行对照研究,确立多平面TEE诊断房间隔缺损的最佳方位和常用切面。结果　食管中下段0°方位四腔心切面是原发孔缺损的最佳显示切面;4 5°方位的双心房切面及13 5°方位的卵圆窝切面是观测继发孔缺损的最佳显示切面;90°方位的上、下腔静脉入口切面是观测静脉窦型缺损的最佳显示切面,上述方位和切面是可清晰显示各型房间隔缺损的的位置和大小。结论　可视化心脏与多平面TEE进行对照研究所确立的多平面TEE最佳方位和常用切面,简化了多平面TEE诊断房间隔缺损的操作过程,缩短了检查时间     

经食管超声心动图在儿童复杂性先天性心脏病手术治疗中的应用价值

目的探讨经食管超声心动图(TEE)对儿童复杂性先天性心脏病(CHD)手术治疗的价值。方法复杂性CHD患者95例,年龄0.3～15.6岁(平均4.3岁),均在体外循环前后进行TEE检查。结果术前TEE首要诊断与手术诊断符合率100%,其中仅7例(7.4%)TEE次要诊断与手术诊断不符。TEE对经胸超声心动图诊断做出补充或修正9例(9.5%),其中6例(6.3%)由于TEE的发现而作出手术方案改变或相应处理。术后TEE成功显示率95.8%(91/95),在91例显示成功患者中,达到预期效果且无残余问题63例(69.2%),发现残余问题28例(30.8%),其中2例(2.2%)由于TEE的发现立即予以处理。结论术前TEE可准确诊断儿童复杂性CHD,有助于制定手术方案,术后TEE可及时发现残余问题,有助于提高手术成功率。     

猪静脉空气栓塞模型的经食管超声心动图实验研究

目的观察空气栓子在猪右心腔内的超声声像图变化及猪静脉空气栓塞的致死量。方法经6头健康梅白猪的颈内静脉依次注入0.05~4ml/kg空气,经食管超声心动图连续观察猪右心腔内声像图变化,并记录静脉空气栓塞的致死量。结果随着注入的空气量增加,右心腔内游动的点状强回声逐渐增多,甚至充满整个心腔,然后逐渐分散消失,排空时间为15s~40min,其中1头实验猪发生反常栓塞。猪静脉空气栓塞的累积致死量为276~667ml。结论经食管超声心动图能敏感检测猪右心腔中空气栓子的超声表现,健康梅白猪静脉空气栓塞的平均累积致死量为(397±105)ml。     

Multidetector row computed tomography for identification of left atrial appendage filling defects in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation: Comparison with transesophageal echocardiography

BACKGROUND: Advances in multidetector computed tomography (MDCT) technology now permit three-dimensional cardiac imaging with high spatial and temporal resolution. Historically, transesophageal echocardiography (TEE) has been the gold standard for assessment of the left atrial appendage (LAA) in patients with atrial fibrillation and other atrial arrhythmias. Findings on TEE, including demonstration of LAA thrombus and dense nonclearing spontaneous echocardiographic contrast (SEC), predict future fatal and nonfatal thromboembolic events. OBJECTIVE: The purpose of this study was to compare the diagnostic performance of 64-detector row MDCT in detecting LAA thrombus and dense nonclearing SEC as identified by TEE in patients undergoing pulmonary vein isolation for treatment of atrial fibrillation. METHODS: A total of 72 consecutive patients (69.4% male; mean age 56.1 +/- 10.3 years) underwent both MDCT and TEE for evaluation of the LAA (median intertest interval 0 days, interquartile range 0-5 days). MDCT assessment of the LAA was performed by two methods: (1) comparison of Hounsfield unit (HU) densities in the LAA apex to the ascending aorta (AscAo) in the same axial plane and (2) nonquantitative visual identification of a filling defect in the LAA. TEE evaluation of the LAA included identification of echodense intracavitary masses in the LAA as well as pulsed-wave Doppler interrogation of the LAA ostium. RESULTS: Patients with LAA thrombus or dense nonclearing SEC by TEE exhibited significantly lower LAA/AscAo HU ratios than patients who did not (0.82 +/- 0.22 vs 0.39 +/- 0.19, P <.001). LAA/AscAo HU cutoff ratios < or = 0.75 correlated to LAA thrombus or dense nonclearing SEC by TEE, with 100% sensitivity, 72.2% specificity, 28.6% positive predictive value, and 100% negative predictive value. HU ratios < or = 0.75 were associated with pulsed-wave Doppler velocities <50 cm/s of the LAA ostium (P <.001). In multivariable analysis, LAA/AscAo HU ratio < or = 0.75 remained a robust predictor of LAA thrombus or dense nonclearing SEC by TEE (P <.001). In contrast, MDCT identification of TEE-identified LAA thrombus or dense nonclearing SEC by visual detection of LAA filling defects resulted in lower sensitivity (50%) and negative predictive value (95.1%). CONCLUSION: Current-generation MDCT successfully identifies LAA thrombus and dense nonclearing SEC with high sensitivity and moderate specificity. Importantly, LAA/AscAo HU ratios >0.75 demonstrate 100% negative predictive value for exclusion of LAA thrombus or dense nonclearing SEC. These results suggest that in patients undergoing pulmonary vein isolation procedures, MDCT examinations that demonstrate LAA/AscAo HU ratios >0.75 may preclude the need for preprocedural TEE.     

术中经食管超声检测肝静脉血流与中心静脉压相关性研究

目的研究肝静脉血流（HVF）与中心静脉压（CVP）相关性。方法经食管超声心动图对24例不停跳冠状动脉旁路移植术中患者，144个时间点与心导管CVP同步检测HVF频谱。结果CVP〈10mmHg（1mmHg=0．133kPa，下同）HVF频谱正向收缩期S波、舒张期D波血流速度（V）和速度时间积分（VTI）大于负向收缩末v波和心房收缩a波。CVP≥10mmHg，S波减低，a波增大，V（S＋D／（v＋a）〈2，VS＋a、Va和Vv与CVP呈显著相关（P=0．000）。VS＋a〈2cm／s，敏感性95．2％，特异性60％。结论术中TEE检测HVF可监测CVP，HVF与CVP有很好的相关性，是评估危重患者CVP的有效方法。