Alexandros Papachristidis

Automatic short axis orientation of the left ventricle in 3D ultrasound recordings

The recent advent of three-dimensional echocardiography has led to an increased interest from the scientific community in left ventricle segmentation frameworks for cardiac volume and function assessment. An automatic orientation of the segmented left ventricular mesh is an important step to obtain a point-to-point correspondence between the mesh and the cardiac anatomy. Furthermore, this would allow for an automatic division of the left ventricle into the standard 17 segments and, thus, fully automatic per-segment analysis, e.g. regional strain assessment. In this work, a method for fully automatic short axis orientation of the segmented left ventricle is presented. The proposed framework aims at detecting the inferior right ventricular insertion point. 211 three-dimensional echocardiographic images were used to validate this framework by comparison to manual annotation of the inferior right ventricular insertion point. A mean unsigned error of 8, 05° ± 18, 50° was found, whereas the mean signed error was 1, 09°. Large deviations between the manual and automatic annotations (> 30°) only occurred in 3, 79% of cases. The average computation time was 666ms in a non-optimized MATLAB environment, which potentiates real-time application. In conclusion, a successful automatic real-time method for orientation of the segmented left ventricle is proposed.

Coronary sinus endocarditis due to tricuspid regurgitation jet lesion

A 28-year-old woman presented with a 2-week history of fever, night sweats, and general malaise. At presentation, she had haemoptysis, shortness of breath, acute kidney injury, and elevated inflammatory markers. She had a history of intravenous drug use and recent hospitalization 4 months ago with Staphylococcus aureus tricuspid valve endocarditis treated conservatively with …

Aortic thrombus causing myocardial infarction after recreational MDMA use

A 20-year-old man presented with a 5-h history of central chest pain radiating to his back and left arm. The ECG showed ST elevation in leads V2 and V3. A trans-thoracic echocardiogram did not show any abnormalities apart from a suspicion of an echogenic structure in the proximal ascending aorta close to the aortic valve. The nature …

The prognostic role of stress echocardiography in a contemporary population and the clinical significance of limited apical ischaemia

Introduction In this study, we aim to reassess the prognostic value of stress echocardiography (SE) in a contemporary population and to evaluate the clinical significance of limited apical ischaemia, which has not been previously studied. Methods We included 880 patients who underwent SE. Follow-up data with regards to MACCE (cardiac death, myocardial infarction, any repeat revascularisation and cerebrovascular accident) were collected over 12 months after the SE. Mortality data were recorded over 27.02 ± 4.6 months (5.5–34.2 months). We sought to investigate the predictors of MACCE and all-cause mortality. Results In a multivariable analysis, only the positive result of SE was predictive of MACCE (HR, 3.71; P = 0.012). The positive SE group was divided into 2 subgroups: (a) inducible ischaemia limited to the apical segments (‘apical ischaemia’) and (b) ischaemia in any other segments with or without apical involvement (‘other positive’). The subgroup of patients with apical ischaemia had a significantly worse outcome compared to the patients with a negative SE (HR, 3.68; P = 0.041) but a similar outcome to the ‘other positive’ subgroup. However, when investigated with invasive coronary angiography, the prevalence of coronary artery disease (CAD) and their rate of revascularisation was considerably lower. Only age (HR, 1.07; P < 0.001) was correlated with all-cause mortality. Conclusion SE remains a strong predictor of patients’ outcome in a contemporary population. A positive SE result was the only predictor of 12-month MACCE. The subgroup of patients with limited apical ischaemia have similar outcome to patients with ischaemia in other segments despite a lower prevalence of CAD and a lower revascularisation rate.

Agitated saline contrast echocardiography reveals cor triatriatum dexter

We present the case of a 54‐year‐old man who had an unusual finding in contrast echocardiography with agitated saline. Partition of the right atrium in two compartments, an opacified and a non‐opacified one, was noted. Further assessment with a transesophageal echocardiogram revealed the presence of a membrane in the right atrium, with the final diagnosis being cor triatriatum dexter.

3DTEE imaging of a descending aorta floating thrombus in a patient with calciphylaxis

We present a case of a 68‐year‐old man with calciphylaxis, who was found to have a floating thrombus in the descending aorta on a transesophageal echocardiogram. The use of 3D echocardiography demonstrated nicely the free motion of the thrombus, emerging from an atherosclerotic plaque in the descending aorta. Anticoagulation was started for thromboembolism prevention.

Agitated saline contrast echocardiography reveals a systemic-to-pulmonary venous shunt

Contrast echocardiography with agitated saline is used to assess mainly the existence of interatrial communication. We report a case of a 26‐year‐old woman, with a “port‐a‐cath” central venous line, who had an unusual finding in agitated saline contrast echocardiography. Multimodality imaging revealed occlusion of superior vena cava and a systemic‐to‐pulmonary venous shunt.

The safety, efficacy and cost-effectiveness of stress echocardiography in patients with high pretest probability of coronary artery disease

Objective In this study, we assess the clinical and cost-effectiveness of stress echocardiography (SE), as well as the place of SE in patients with high pretest probability (PTP) of coronary artery disease (CAD). Methods We investigated 257 patients with no history of CAD, who underwent SE, and they had a PTP risk score >61% (high PTP). According to the National Institute for Health and Care Excellence guidance (NICE CG95, 2010), these patients should be investigated directly with an invasive coronary angiogram (ICA). We investigated those patients with SE initially and then with ICA when appropriate. Follow-up data with regard to Major Adverse Cardiac and Cerebrovascular Events (MACCE, defined as cardiovascular mortality, cerebrovascular accident (CVA), myocardial infarction (MI) and late revascularisation for acute coronary syndrome/unstable angina) were recorded for a period of 12 months following the SE. The tariff for SE and ICA is £300 and £1400, respectively. Results 106 patients had a positive SE (41.2%) and 61 of them (57.5%) had further investigation with ICA. 15 (24.6%) of these patients were revascularised. The average cost per patient for investigations was £654.09. If NICE guidance had been followed, the cost would have been significantly higher at £1400 (p<0.001). Overall, 5 MACCE (2.0%) were recorded; 4 (3.8%) in the group of positive SE (2 CVAs and 2 MIs) and 1 (0.7%) in the group of negative SE (1 CVA). There was no MI and no need for revascularisation in the negative SE group. Conclusion Our approach to investigate patients who present with de novo chest pain and high PTP, with SE initially and subsequently with ICA when appropriate, reduces the cost significantly (£745.91 per patient) with a very low rate of MACCE. However, this study is underpowered to assess safety of SE.

Standardized Delineation of Endocardial Boundaries in Three-Dimensional Left Ventricular Echocardiograms

Background Three‐dimensional (3D) echocardiography is fundamental for left ventricular (LV) assessment. The aim of this study was to determine discrepancies in 3D LV endocardial tracings and suggest tracing guidance. Methods Forty‐five 3D LV echocardiographic data sets were traced by three experienced operators, from different centers, according to predefined guidelines. The 3D meshes were compared with one another, and the endocardial areas of discrepancies were identified. A discussion and retracing protocol was used to reduce discrepancies. For each data set, an average 3D mesh was produced (reference mesh). Subsequently, four novice operators, divided into two groups, traced 20 of the data sets. Two operators followed the tracing protocol and two did not. Results The intraclass correlation coefficients among the three experienced operators for end‐diastolic volume, end‐systolic volume, and ejection fraction were 0.952, 0.955, and 0.932. The absolute distances between tracings were 1.11 ± 0.45 mm. The highest tracing discrepancies were at the apical cap and anterior and anterolateral walls in end‐diastole and end‐systole and also at the basal anteroseptum in end‐systole. Agreement with the reference meshes was better for the novice operators who followed the guidance (10.9 ± 17.3 mL, 10.2 ± 14.7 mL, and −2.2 ± 4.1% for end‐diastolic volume, end‐systolic volume, and ejection fraction) compared with those who did not (16.3 ± 16.4 mL, 17.0 ± 16.0 mL, and −4.2 ± 4.1%, respectively). Conclusions Comparing 3D LV tracings, the endocardial areas that are the most difficult to delineate were identified. The suggested protocol for LV tracing resulted in very good agreement among operators. The reference 3D meshes are available for online testing and ranking of LV tracing algorithms. Graphical abstract Figure. No Caption available. HighlightsThe authors propose a protocol for 3D ultrasound LV endocardial tracing.By direct comparison of three operators’ tracings, the areas of highest distance errors were identified.The authors provide reference 3D LV meshes for evaluation of tracing algorithms.The suggested tracing protocol can improve the accuracy of novice operators’ tracings.

Left atrial volumetric assessment using a novel automated framework for 3D echocardiography: a multi-centre analysis

Aims This study aims at validating a software tool for automated segmentation and quantification of the left atrium (LA) from 3D echocardiography. Methods and results The LA segmentation tool uses a dual-chamber model of the left side of the heart to automatically detect and track the atrio-ventricular plane and the LA endocardium in transthoracic 3D echocardiography. The tool was tested in a dataset of 121 ultrasound images from patients with several cardiovascular pathologies (in a multi-centre setting), and the resulting volumes were compared with those assessed manually by experts in a blinded analysis using conventional contouring. Bland-Altman analysis showed good agreement between the automated method and the manual references, with differences (mean ± 1.96 SD) of 0.5 ± 5.7 mL for LA minimum volume and -1.6 ± 9.7 mL for LA maximum volume (comparable to the inter-observer variability of manual tracings). The automated tool required no user interaction in 93% of the recordings, while 4% required a single click and only 2% required contour adjustments, reducing considerably the amount of time and effort required for LA volumetric analysis. Conclusion The automated tool was validated in a multi-centre setting, providing quantification of the LA volume over the cardiac cycle with minimal user interaction. The results of the automated analysis were in agreement with those estimated manually by experts. This study shows that such approach has clinical utility for the assessment of the LA morphology and function, automating and facilitating the time-consuming task of analysing 3D echocardiographic recordings.