Left Ventricular Opacification Research Articles

Contrast Tuned Imaging for Detection of Left Ventricular apical thrombus: A Case Report

Thrombi represent the most frequently found intracardiac masses. Left ventricular thrombus (LVT) is an important complication in patients with ischemic heart diseases and in those with dilated cardiomyopathy and systolic heart failure. The diagnosis of left ventricular thrombus remains important since anticoagulation will reduce the risk of systemic embolization and stroke. Despite advances in other imaging modalities, echocardiography remains the most important tool for diagnosis and risk stratification in patients predisposed to develop left ventricular thrombi. We are presenting a case report of 62 years old gentleman who had suffered from anterior wall myocardial infarction (AWMI) in the recent past, and now has developed LVT which was detected by contrast tuned imaging (CTI) technology based contrast echocardiography. This is a first case report of detection of LVT by this ingenious technology. Keywords: Thrombus, Left Ventricle, Ischemic Heart Disease, Anterior Wall Myocardial Infarction, Contrast Tuned Imaging, Left Ventricular Opacification.

Automatic Myocardial Contrast Echocardiography Image Quality Assessment Using Deep Learning: Impact on Myocardial Perfusion Evaluation.

The image quality of myocardial contrast echocardiography (MCE) is critical for precise myocardial perfusion evaluation but challenging for echocardiographers. Differences in quality may lead to diagnostic heterogeneity. This study was aimed at achieving automatic MCE image quality assessment using a deep neural network (DNN) and investigating its impact on myocardial perfusion evaluation. The Resnet-18 model was used for training and testing on internal and external data sets. Quality assessment involved three aspects: left ventricular opacification (LVO), shadowing, and flash adequacy; the quality score was calculated based on image quality. This study explored the impact of the DNN-based quality score on perfusion evaluation (normal, delay or obstruction) by echocardiographers (two seniors, one junior and one novice). Additionally, the effect of the score difference between re-scans on perfusion evaluation was investigated. The time cost for DNN prediction was 0.045 s/frame. In internal validation and external testing, the DNN achieved F1 and macro F1 scores >90% for quality assessment and had high intraclass correlation coefficients (0.954 and 0.892, respectively) in sequence quality scores. The proportion of segments deemed uninterpretable increased as the DNN-based quality score decreased. The agreement of perfusion assessment between one senior and others decreased as the quality score decreased. And the greater the score difference between the re-scans, the lower was the agreement on perfusion assessment by the same echocardiographer. This study determined the effectiveness of DNN for real-time automatic MCE quality assessment. It has the potential to reduce the variability in perfusion evaluation among echocardiographers.

Clinical study on LVO-based evaluation of left ventricular wall thickness and volume of AHCM patients

ObjectiveThe aim of this study is to evaluate the clinical value of left ventricular opacification (LVO) in detecting left ventricular wall thickness (LVWT) and left ventricular (LV)volume in patients with apical hypertrophic cardiomyopathy (AHCM). MethodsConventional two-dimensional echocardiography (2DE) and LVO dynamic images of apical four-chamber (AP4C), apical two-chamber(AP2C), and short axis views of the basal, middle, and apical segments were collected from 27 AHCM patients and 33 normal subjects. LVWT（including 16 segments at 3 different levels）and LV volume were measured by both 2DE and LVO, compared between the two groups. Results(1) LVWT of the middle and the apical segments were higher in the AHCM than those in the control group measured by both LVO and 2DE (P < 0.001). (2) LVWT at the basal, middle and apical segments measured by LVO in the two groups were lower than those by 2DE, (P < 0.001). In the control group, the LVWT decreased from the basal to the apical segment, while in the AHCM group, the LVWT increased from the base to the apex,(P < 0.001).(3)LVEDV, LVESV, SV obtained by LVO were higher.than those by 2DE in the two groups (P < 0.001). LVEDV, LVESV and SV in the AHCM group were lower compared to the control group(P < 0.001).(4)The intra-observer repeatability of LVWT and LV volum in AHCM patients measured by LVO were higher than those by 2DE(P < 0.001). Conclusion(1)LVO can improve the delineation of the endocardial border, enabling more accurate diagnosis of AHCM than by 2DE. (2) LVO can improve display of the LV apical structure, leading to more accurate evaluation of LVWT, and LV volume, than by 2DE, in patients with AHCM; potentially providing more reliable information for clinical diagnosis and treatment and meriting wider clinical application.

Established and emerging roles for ultrasound enhancing agents (contrast echocardiography).

The ability to opacify the left ventricle and delineate the endocardium after intravenous injection of microbubble ultrasound enhancing agents is of established value to quantify volumes and function in suboptimal unenhanced images, particularly in stress echocardiograms. However, applications other than quantitation of left ventricle structure and function exist for contrast enhanced left ventricular opacification. Contrast agents enable recording of Doppler velocity signals in patients with poor ultrasound transmission, providing estimates of aortic stenosis gradient and pulmonary artery pressures. Contrast echo is of value in detecting apical hypertrophic cardiomyopathy and accompanying apical aneurysms. Most importantly, ultrasound enhancing agents can identify apical and left atrial masses when they cannot be visualized in unenhanced images, and can distinguish thrombi from tumors by visualizing the vascularity inherent in tumors. Contrast agents distinguish trabecular from compacted myocardium in noncompaction syndrome, and hypertrabeculation with other abnormal conditions. A major potential application of ultrasound enhancing agents is myocardial opacification, which can assist in identifying nonviable myocardium. Also, the delayed reappearance of myocardial perfusion after microbubble destruction identifies impaired contrary flow and can diagnose coronary stenosis. Innovative applications of ultrasound contrast agents currently under investigation, include visualizing the vaso vasorum to identify plaques and assess their vulnerability, and theranostic agents to deliver drugs and biologists and to assist in sonothrombolysis. It is anticipated that the role of ultrasound contrast agents will continue to increase in the future.

Automatic view classification of contrast and non-contrast echocardiography.

BackgroundContrast and non-contrast echocardiography are crucial for cardiovascular diagnoses and treatments. Correct view classification is a foundational step for the analysis of cardiac structure and function. View classification from all sequences of a patient is laborious and depends heavily on the sonographer’s experience. In addition, the intra-view variability and the inter-view similarity increase the difficulty in identifying critical views in contrast and non-contrast echocardiography. This study aims to develop a deep residual convolutional neural network (CNN) to automatically identify multiple views of contrast and non-contrast echocardiography, including parasternal left ventricular short axis, apical two, three, and four-chamber views.MethodsThe study retrospectively analyzed a cohort of 855 patients who had undergone left ventricular opacification at the Department of Ultrasound Medicine, Wuhan Union Medical College Hospital from 2013 to 2021, including 70.3% men and 29.7% women aged from 41 to 62 (median age, 53). All datasets were preprocessed to remove sensitive information and 10 frames with equivalent intervals were sampled from each of the original videos. The number of frames in the training, validation, and test datasets were, respectively, 19,370, 2,370, and 2,620 from 9 views, corresponding to 688, 84, and 83 patients. We presented the CNN model to classify echocardiographic views with an initial learning rate of 0.001, and a batch size of 4 for 30 epochs. The learning rate was decayed by a factor of 0.9 per epoch.ResultsOn the test dataset, the overall classification accuracy is 99.1 and 99.5% for contrast and non-contrast echocardiographic views. The average precision, recall, specificity, and F1 score are 96.9, 96.9, 100, and 96.9% for the 9 echocardiographic views.ConclusionsThis study highlights the potential of CNN in the view classification of echocardiograms with and without contrast. It shows promise in improving the workflow of clinical analysis of echocardiography.

An Open Access Chamber Designed for the Acoustic Characterisation of Microbubbles

Microbubbles are used as contrast agents in clinical ultrasound for Left Ventricular Opacification (LVO) and perfusion imaging. They are also the subject of promising research in therapeutics as a drug delivery mechanism or for sonoporation and co-administration. For maximum efficacy in these applications, it is important to understand the acoustic characteristics of the administered microbubbles. Despite this, there is significant variation in the experimental procedures and equipment used to measure the acoustic properties of microbubble populations. A chamber was designed to facilitate acoustic characterisation experiments and was manufactured using additive manufacturing techniques. The design has been released to allow wider uptake in the research community. The efficacy of the chamber for acoustic characterisation has been explored with an experiment to measure the scattering of SonoVue® microbubbles at the fundamental frequency and second harmonic under interrogation from emissions in the frequency range of 1.6 to 6.4 MHz. The highest overall scattering values were measured at 1.6 MHz and decreased as the frequency increased, a result which is in agreement with previously published measurements. Statistical analysis of the acoustic scattering measurements have been performed and a significant difference, at the 5% significance level, was found between the samples containing contrast agent and the control sample containing only deionised water. These findings validate the proposed design for measuring the acoustic scattering characteristics of ultrasound contrast agents.

Comparison of two ultrasound contrast agents for left ventricular opacification

Abstract Funding Acknowledgements Type of funding sources: None. Background Several ultrasound contrast agents have been approved and used for measurement of LV volumes and ejection fraction (EF). However, there has been no direct comparison between these agents. Purpose To compare different imaging parameters between two widely used ultrasound contrast agents for LV opacification when imaged with a low power contrast specific imaging modality Methods A retrospective study was performed using recordings of the local echocardiography registry for patients undergoing chemotherapy for cancer treatment. Patients were included who underwent follow-up echocardiograms (3 months) with 2 different ultrasound contrast agents and had only minor changes in the LV ejection fraction (EF) between the studies (&amp;lt;5%). Qualitative and quantitative analysis of the contrast effect was performed in apical four- and two chamber views (4CV,2CV). For quantitative analysis of the LV opacification square regions of interest (ROI) were placed in the apical and basal regions of the ventricle in each echocardiographic recording and the arithmetic mean and standard deviation of pixel intensity within each ROI was recorded throughout the entire loop. Qualitative visual assessment was performed using a three step visual score in order to assess the endocardial border delineation, basal attenuation and apical swirling. Wilcoxon signed-rank test was used to compare the measurements obtained with different contrast agents. Results 41 patients fulfilled the inclusion criteria. In all patients suitable recordings for measurement of LV volumes and EF were obtained. The mean + standard deviation of the EF was 61 + 9%. Both contrast agents provided intensive LV opacification in the basal and apical cavities. The video intensities (mean + standard deviation) in the apical and basal cavities were comparable across both contrast agents in the 2CV apical ROI (219.96 + 21.42 vs 224.69 + 20.23, p = 0.32), the 2CV basal ROI (114.55, 42.02 vs 112.79, 42.57, p = 0.81), the 4CV apical ROI (228.02, 17.80 vs 225.51, 20.37, p = 0.30), and the 4CV basal ROI (100.05, 41.11 vs 92.84, 42.54, p = 0.37). Visual assessment of endocardial delineation on end-diastolic and end-systolic frames revealed no statistical difference between the contrast agents. Conclusion In patients with normal LV function no clinically relevant differences were found between the two contrast agents regarding LV opacification and endocardial border delineation.

Manual zur Indikation und Durchführung spezieller echokardiographischer Anwendungen

Das zweite Manual zur Indikation und Durchführung der Echokardiographie bezieht sich auf spezifische Anwendungen der Echokardiographie und besondere Fragestellungen bei speziellen Patientengruppen. Dabei stehen v. a. praktische Aspekte im Vordergrund. Methodisch etabliert sind die transösophageale Echokardiographie, die Stressechokardiographie und die Kontrastechokardiographie. Bei nahezu allen echokardiographischen Untersuchungen spielen aktuell 3‑D-Echokardiographie und Deformationsbildgebung eine Rolle. Das gesamte Spektrum der echokardiographischen Möglichkeiten wird derzeit in Notfall- und Intensivmedizin, bei der Überwachung und Führung von Katheterinterventionen, bei strukturellen Herzerkrankungen, bei herzchirurgischen Operationen, bei der Nachsorge von kardialen Unterstützungssystemen, bei kongenitalen Vitien im Erwachsenenalter und bei der Versorgung von hochinfektiösen Patienten in Pandemiezeiten angewandt. Die diagnostischen Fortschritte der konventionellen und modernen echokardiographischen Anwendungen stehen im Fokus dieses Manuals. Die 3‑D-Echokardiographie zur Charakterisierung der kardialen Morphologie und die Deformationsbildgebung zur Objektivierung der kardialen Funktion sind bei vielen Indikationen im klinischen Alltag etabliert. Die Stressechokardiographie zur Ischämie‑, Vitalitäts- und Vitiendiagnostik, die Bestimmung der koronaren Flussreserve und die Kontrastechokardiographie bei der linksventrikulären Wandbewegungsanalyse und kardialen Tumordetektion finden zunehmend klinische Anwendung. Wie für die konventionelle Echokardiographie im ersten Manual der Echokardiographie 2009 beschrieben, erfordert der Einsatz moderner echokardiographischer Verfahren die standardisierte Dokumentation und Akquisition bestimmter Bildsequenzen bei optimierter Geräteeinstellung, da korrekte und reproduzierbare Auswertungen nur bei guter Bildqualität möglich sind.Zusatzmaterial onlineDie Online-Version dieses Beitrags (10.1007/s12181-021-00509-1) enthält ein Abkürzungs‑, Tabellen‑, Abbildungsverzeichnis.

Review of ultrasound contrast agents in current clinical practice with special focus on DEFINITY® in cardiac imaging.

Echocardiography is the most widely used noninvasive modality to evaluate the structure and function of the cardiac muscle in daily practice. However, up to 15-20% of echocardiograms are considered suboptimal. To enable accurate assessment of cardiac function and wall motion abnormality, the use of ultrasound microbubble contrast has shown substantial benefits in cases of salvaging nondiagnostic studies and enhancing the diagnostic accuracy in daily practice. DEFINITY® is a perflutren based, lipid shelled microbubble contrast agent, which is USFDA approved for left ventricular opacification. The basis of ultrasound microbubbles, its development, and the clinical role of DEFINITY(characteristics, indications and case examples, side effect profile and existing evidence) is the subject of discussion in this review.

Myocardial Contrast Uptake in Relation to Coronary Artery Disease and Prognosis

During left ventricular opacification (LVO), myocardial contrast uptake (MCU) is frequently observed, but its clinical implication is uncertain. We aimed to investigate the diagnostic performance of MCU and its prognostic value in known or suspected coronary artery disease (CAD). Contrast echocardiography was retrospectively analyzed in 457 patients who had previous coronary angiography <12 mo before LVO. MCU was classified into replacement or interstitial patterns. Subendocardial patterns were further inspected. Events were defined as a primary composite of the occurrence of acute coronary syndrome, heart failure hospitalization, sustained ventricular tachycardia and all-cause mortality. MCU had an 87.6% sensitivity, 75.5% specificity, 73.0% positive predictive value and 87.7% negative predictive value in detecting CAD. After a median follow-up of 17.3 mo, 52 events occurred. Replacement, interstitial and subendocardial MCU patterns were associated with events. In conclusion, the presence of MCU was useful in identifying CAD and provided incremental prognostic value for clinical outcomes.

336 Efficacy With Use of Ultrasound Enhancing Agents at the Townsville Hospital

The use of Ultrasound Enhancing Agents (UEAs) has become an integral part in Echocardiography. The Cardiac Investigation Unit (CIU) at the Townsville Hospital uses Definity. The indications are left ventricular (LV) opacification and delineation of LV endocardial border but off-label clinical applications are very useful in clinical echocardiography. The only contraindication is hypersensitivity to perflutren. Aim of our study is to demonstrate the indications, effectiveness and influence on clinical decision making using UEAs in echocardiography. This is an audit of UEA use in echocardiograms done in CIU during 2017. 202 echocardiograms were examined. The demographics revealed 73% of the patients were male; median age was 62. Transthoracic echocardiograms were majority (79%), with stress-echocardiogram (20%) and trans-oesophageal echocardiogram (1%). 46% were outpatients and the rest were inpatients [CCU (24%), Wards (10%), and ICU (2%)]. Indications were enhancement of endocardial definition (80%), quantification of LV ejection fraction and LV volumes (59%), assessment of LV apex (24%), exclusion of intra-cardiac masses (12%), and Doppler enhancement (2.5%). The success rates were 95%, 96%, 98%, 90% and 69% respectively. Clinical implications showed no change in management (79%), medication change (9%), procedural change (7%), changes in both (2%) and inadequate imaging (3%). Only one patient had complication as back pain. Use of UEAs in our Echo Lab has shown to be very effective in multiple clinical applications, avoiding other down-stream investigations without causing major complications. It also helps in clinical decision making leading to changes in management in 18% of the cases.

The evaluation of post-infarction ventricular septal rupture and the risk factors of death by left ventricular opacification and real-time three-dimensional echocardiography

Objective To study the local morphology of post-infarction ventricular septal rupture (PI-VSR) and the left ventricular function before and after operation and to evaluate the relevant risk factors of death in patients with PI-VSR by using left ventricular opacification (LVO) combined with real-time three-dimensional echocardiography (RT-3DE). Methods Twenty-eight patients with PI-VSR and 19 patients undergoing surgical treatment were selected. The consistency of two-dimensional ultrasound, RT-3DE and the detection of LVO on the maximum diameter, location, number and shape of ventricular septal rupture (VSR) with the surgical results were compared. Through LVO combined with RT-3DE, the changes of left ventricular function indexes before and after surgery were compared. According to the general data and clinical data of patients, independent risk factors affecting survival and prognosis were explored. Results ①There was no significant difference between LVO and RT-3DE in detecting VSR maximum diameter and surgical results (all P>0.05). The location, number and shape of VSR detected by LVO were consistent with the surgical results (all P<0.05). RT-3DE had good consistency in detecting VSR location, shape and surgical results (all P<0.05). Among them, of LVO′s detection of VSR location and shape and the Kappa values of consistence of the intraoperative results were 0.650 and 0.883 respectively. LVO had a sensitivity of 0.923, specificity of 1.000, accuracy of 0.947, positive predictive value of 1.000 and negative predictive value of 0.857 in observing VSR shape. ②LVO combined with RT-3DE was used to evaluate the left ventricular function of postoperative patients. The parameters of left ventricular function improved significantly(all P<0.05). ③The independent risk factors affecting the 30 d survival rate included: gender, Killips pump function classification, and whether or not surgery was performed. Conclusions LVO and RT-3DE can provide more accurate anatomical information such as VSR maximum diameter, location, number and shape, which provides the basis for the selection of treatment strategy. LVO combined with RT-3DE can evaluate the changes of left ventricular function before and after surgery, which can provide reference for clinical evaluation of prognosis. Key words: Echocardiography, real-time three-dimensional; Ventricular septal rupture; Left ventricular opacification; Risk factor

Is 3D Dobutamine stress echocardiography ready for prime time? Diagnostic and prognostic implications.

Compare the diagnostic accuracy and prognostic value of echo contrast enhanced 2D and 3D Dobutamine stress echocardiography (DSE). We included 718 patients indicated for DSE. All had standard 2D, and contrast enhanced left ventricular opacification (LVO) for 2D and 3D acquisitions at rest and peak stress. Chi-square test was done to assess relationship between DSE result and early revascularization. Kaplan-Meier plots with Logistic regression analysis predicted late major adverse cardiovascular events (MACE) at a maximum follow-up of 84 months. The mean age was 63 ± 13 years (61% males) and follow-up was obtained in 692/718 (96.4%) patients. Only 32% had excellent baseline image quality. The DSE was abnormal in 19.4% patients on 2D, in 17.1% on 2D-LVO and in 19.1% on 3D-LVO. Early revascularization was performed in, respectively, 32.8%, 45.8%, and in 48.5% of stress-positive 2D, 2D-LVO, and 3D-LVO studies. After excluding the 66 patients receiving early revascularization 68/626 (10.9%) had MACE at a maximum follow-up of 84 months. Kaplan-Meier plots showed that stress-positive 2D-LVO and 3D-LVO studies not receiving early revascularization when assessed separately and combined had significantly worse outcomes for MACE compared with stress-negative patients (OR 3.69; 95% CI: 1.54-8.87; P = 0.011, OR 4.54; 95% CI: 1.72-12.93; P = 0.008, and OR 7.07, 95% CI: 1.62-25.16; P = 0.001, respectively). Combined use of 2D- and 3D-LVO DSE is ready for prime time considering the feasibility, improved diagnostic accuracy and prognostic value.

Differentiation of patients with two-dimensional echocardiography false positive non-compaction of ventricular myocardium by contrast echocardiography.

Although echocardiography can be used to detect patients with non-compaction of the ventricular myocardium, it is often difficult to diagnose. In this study, the endocardium may be clearly visualized by contrast echocardiography to improve the diagnostic accuracy of patients with noncompaction of the ventricular myocardium. Twenty-four patients (n = 24) suspected with non-compaction of the ventricular myocardium Underwent transthoracic echocardiography including an intracardiac contrast echocardiography. The clinical data, Left ventricular opacification, and contrast echocardiography results were analyzed retrospectively. Twenty-four patients (n = 24) suspected with non-compaction of the ventricular myocardium were classified with transthoracic echocardiography and contrast echocardiography results into two groups: false positive and true positive. There were no significant differences in age, predisposing segments, Left Ventricular End-Diastolic Diameter, Left Ventricular End-Diastolic Volume, Left Ventricular End-Systolic Diameter, Left Ventricular End-Systolic Volume and ejection fraction between the two groups (P>0.05). The thickness ratio of noncompacted to compacted myocardium (N/C) in the true positive group was significantly higher than that in the false positive group (3.47 ± 1.31 vs. 4.96 ± 1.28; P<0.05). The range of noncompact myocardium in non-compaction of the ventricular myocardium patients can be observed clearly by Left ventricular opacification. Contrast medium in trabecular space and crypt is plentiful and ultrasonic contrast is more objective in measuring the thickness of dense myocardium. Two-dimensional echocardiography plays a characteristic role in the diagnosis of non-compaction of the ventricular myocardium; however, some suspected patients were observed to be false positive. Left ventricular opacification can greatly improve the clarity and accuracy of the endocardial margin by enhancing left ventricular imaging, displaying the true dense and non-dense layers, and improve the accuracy of ultrasonic diagnosis of non-compaction of the ventricular myocardium. The purpose of this paper was to explore the applied value of contrast echocardiography for heart diagnosis.

Poster Session - Poster session 2

Background: Preliminary studies suggest that myocardial scar can be visualised by transthoracic echocardiography (TTE) using a low mechanical index (MI). Data describing the usefulness of scar imaging by TTE to predict myocardial viability are limited. Purpose: We investigated the association between myocardial scar, as imaged by low MI TTE, and viability as assessed by low-dose dobutamine stress echocardiography (DSE). Methods: We analysed 59 patients who had rest echocardiography including low MI (0.4-0.5) scans and DSEs, performed for myocardial viability between 29/04/2015 to 16/05/2018. Median age was 64 years (interquartile range 57-71), 55 (93%) were male. Left ventricular contrast opacification SonoVue (Braco) was used according to American Society of Echocardiography (ASE) standards (n = 39). Two experienced cardiologists blindly and independently performed 16-segment scar assessment at rest. Viability by DSE was used to represent the ‘gold standard’, from which sensitivity, specificity, negative and positive predictive values of viability assessed by scar at rest were calculated. Results: 42 (71%) of studies had evidence of scar at rest identified by low MI imaging. Presence of scar at rest has a sensitivity of 42%, specificity of 92%, positive and negative predictive values of 82 and 64%, respectively (Table 1). Specificity was higher in non-contrast compared to contrast images, at 97 and 90 %, respectively. The right coronary artery territory had a lower specificity compared to left anterior descending and circumflex territories. Conclusions: Presence of scar at rest has a low sensitivity but high specificity to predict non-viability on low-dose DSE. The presence of scar at rest TTE has the potential to reduce the need for low-dose DSE as these patients are unlikely to have viable myocardium in this region.

The value of left ventricular angiography in the diagnosis of apical hypertrophic cardiomyopathy

Objective To assess the diagnostic value of left ventricular angiography in patients with apical hypertrophic cardiomyopathy. Methods A total of 32 consecutively recruited patients aged from 61 to 78 with suspected apical hypertrophic cardiomyopathy from inconclusive apex imaging on conventional echocardiography from June 2016 to December 2017 underwent left ventricular opacification.A diagnosis of apical hypertrophic cardiomyopathy was made when the thickness of hypertrophied area of the apex was >1.5 cm, the ratio of the hypertrophied area to the non-hypertrophied area was >1.3, and no hypertrophy was found elsewhere. Results Twenty-four out of 32 patients (75.0%) were diagnosed with apical hypertrophic cardiomyopathy, all of whom had pure apical hypertrophy.The other 8 patients were excluded, with normal thickness in the apex.Patients with apical hypertrophic cardiomyopathy had apical wall thicknesses ranging from 15 mm to 21 mm, reduced myocardial motion amplitude in the apex and uneven echo at certain areas of the ventricular wall.All cases showed clear images of the apex with left ventricular opacification, and the apex of the heart lost its normal morphology and showed a pointed end, with ventricular cavity obliteration or uneven wall thickness in the apex. Conclusions Left heart ventricular angiography can be complimentary to conventional echocardiography in the diagnosis of apical hypertrophic cardiomyopathy by providing a clearer endocardial contour and more accurate estimates of apical wall thickness and therefore enhancing the diagnostic value of ultrasound for apical hypertrophic cardiomyopathy. Key words: Cardiomyopathy, hypertrophic; Echocardiography; Angiocardiography

Effect of Temperature on the Size Distribution, Shell Properties, and Stability of Definity®

Physical characterization of an ultrasound contrast agent (UCA) aids in its safe and effective use in diagnostic and therapeutic applications. The goal of this study was to investigate the impact of temperature on the size distribution, shell properties, and stability of Definity®, a U.S. Food and Drug Administration-approved UCA used for left ventricular opacification. A Coulter counter was modified to enable particle size measurements at physiologic temperatures. The broadband acoustic attenuation spectrum and size distribution of Definity® were measured at room temperature (25 °C) and physiologic temperature (37 °C) and were used to estimate the viscoelastic shell properties of the agent at both temperatures. Attenuation and size distribution was measured over time to assess the effect of temperature on the temporal stability of Definity®. The attenuation coefficient of Definity® at 37 °C was as much as 5 dB higher than the attenuation coefficient measured at 25 °C. However, the size distributions of Definity® at 25 °C and 37 °C were similar. The estimated shell stiffness and viscosity decreased from 1.76 ± 0.18 N/m and 0.21 × 10–6 ± 0.07 × 10–6 kg/s at 25 °C to 1.01 ± 0.07 N/m and 0.04 × 10–6 ± 0.04 × 10–6 kg/s at 37 °C, respectively. Size-dependent differences in dissolution rates were observed within the UCA population at both 25 °C and 37 °C. Additionally, cooling the diluted UCA suspension from 37 °C to 25 °C accelerated the dissolution rate. These results indicate that although temperature affects the shell properties of Definity® and can influence the stability of Definity®, the size distribution of this agent is not affected by a temperature increase from 25 °C to 37 °C.

Incremental value of contrast echocardiography in the diagnosis of left ventricular noncompaction.

Contrast echocardiography with left ventricular opacification (LVO) improves the definition of endocardium in two-dimensional echocardiography (2DE). This study was aimed to determine whether LVO offered added diagnostic value in noncompaction of left ventricular myocardium (NCVM). A total of 85 patients (40 ± 20 years, 54 males) with suspected NCVM were subjected to transthoracic 2DE and LVO, and 40 healthy volunteers were examined with 2DE and assigned as control subjects. The location of NCVM, the thickness ratio of noncompacted to compacted myocardium (NCR), and the cavity size and ejection fraction of LV were quantified. Results revealed that NCVM was mainly located in the LV medium (53.2%), apical (46.2%) segments, and lateral wall (39.8%). The NCR obtained through LVO was greater than that detected through 2DE (4.2 ± 1.3 vs. 3.3 ±1.2, P < 0.001), and higher inter-correlations and less intra- and inter-observer variabilities were determined in the former than in the latter. The NCVM detection rates were also increased from 63.5% via 2DE to 83.5% via LVO and 89.4% via 2DE combined with LVO (2DE + LVO) (P = 0.0004). The LV cavity size was greater and the LVejection fraction (LVEF) was lower in the NCVM patients than in the control group (P < 0.01). In the NCVM group, the LV cavity size was higher and the LVEF was lower in LVO than in 2DE (P < 0.01). In conclusion, contrast echocardiography contributes significant sensitivity and reproducibility to routine transthoracic echocardiography in NCVM diagnosis. Therefore, this technique should be clinically performed to diagnose suspected NCVM.

Safety and Efficacy of Cardiac Ultrasound Contrast in Children and Adolescents for Resting and Stress Echocardiography

Small pilot studies of ultrasound contrast (UC) echocardiography in children have suggested that it is safe; therefore, larger scale evaluation of safety and efficacy in this population is of particular interest. This was a retrospective study (January 2005 to June 2014). Known intracardiac shunt was the only exclusion criterion. UC echocardiography was performed on commercially available ultrasound systems using Definity (3% infusion). When indicated, real-time myocardial contrast echocardiography was performed at rest and stress, with examination of myocardial contrast replenishment, plateau intensity, and wall motion. The primary outcome was short-term safety and efficacy (<24hours). In all, 113 patients (55% male; mean age, 17.8±3years; age range, 5-21 years) underwent UC echocardiography for left ventricular opacification or stress wall motion and perfusion analysis. Diagnosis categories were congenital heart disease (30%), acquired heart disease (21%), and other (suspected cardiac complications of disease of other organ systems; 49%). Twelve patients (11%) with right ventricular systolic pressures>40mmHg received UC without complications; four of these (33%) had the highest right ventricular-right atrial gradient recorded with ultrasound contrast-enhanced Doppler. Myocardial perfusion and/or UC echocardiography-detected wall motion abnormalities were seen in 13 patients (12%); four had confirmed correlations by angiography or magnetic resonance imaging. There were 13 instances of adverse events or reported symptoms during UC echocardiography. All symptoms and events were transient, all patients completed protocols, and there were no immediate sequelae. These data demonstrate the usefulness and safety of UC echocardiography in children and adolescents for a wide variety of indications. UC echocardiography provided myocardial perfusion and wall motion information important in clinical decision making.

GW26-e2283 Incremental Value of Contrast Echocardiography in the Diagnosis of Left Ventricular Noncompaction

Contrast echocardiography with left ventricular opacification (LVO) can improve endocardium definition and potentially becomes supplement of conventional two-dimensional echo (2DE) in the diagnosis of noncompaction of the ventricular myocardium (NCVM). This study aimed to access the feasibility,