Shear wave echocardiography

In this thesis we demonstrate that the assessment of the diastolic function of the left ventricle withclassical echocardiography remain

A simple, fast and reproducible echocardiographic approach to grade left ventricular diastolic function

The American Society of Echocardiography and European Association of Echocardiography (ASE/EAE) have published an algorithm for the grading of diastolic function. However, the ability to use this algorithm effectively in daily clinical practice has not been investigated. We hypothesized that in some patients it may be difficult to grade diastolic dysfunction with this scheme, since there may be discrepancies in the assessed parameters. The aim of the current study was to test the feasibility of the ASE/EAE algorithm and to compare this with a new Thoraxcenter (TXC) algorithm. The ASE/EAE and TXC algorithms were applied to 200 patients. The ASE/EAE algorithm starts with assessment of diastolic myocardial wall velocities and left atrial (LA) volumes with subsequent assessment of E/A ratio, E-wave deceleration time and pulmonary venous flow. The TXC algorithm reverses these steps, uses LA dimension instead of volume and does not include a Valsalva manoeuvre and pulmonary venous flow. Due to inconsistencies between diastolic myocardial wall velocities and LA volumes and a not covered E/A ratio in the range of 1.5–2 it was not possible to classify 48 % of patients with the ASE/EAE algorithm, as opposed to only 10 % by the TXC algorithm. LA volume was always needed in the ASE/EAE algorithm. In only 64 % of patients LA size was necessary by the TXC algorithm. When LA volume would have been used instead of LA dimension, grading of LV diastolic function would have been different in only 2 % of patients without apparent improvement. Assessment of LA dimension was considerably faster than LA volume. The TXC algorithm to grade LV diastolic dysfunction was compared to the ASE/EAE algorithm simpler, faster, better reproducible and yields a higher diagnostic outcome

Tissue drives lesion: computational evidence of interspecies variability in cardiac radiofrequency ablation

Radiofrequency catheter ablation (RFCA) is widely used for the treatment of various types of cardiac arrhythmias. Typically, the efficacy and the safety of the ablation protocols used in the clinics are derived from tests carried out on animal specimens, including swines. However, these experimental findings cannot be immediately translated to clinical practice on human patients, due to the difference in the physical properties of the types of tissue. Computational models can assist in the quantification of this variability and can provide insights in the results of the RFCA for different species. In this work, we consider a standard ablation protocol of 10g force, 30W power for 30s. We simulate its application on a porcine cardiac tissue, a human ventricle and a human atrium. Using a recently developed computational model that accounts for the mechanical properties of the tissue, we explore the onset and the growth of the lesion along time by tracking its depth and width, and we compare the lesion size and dimensions at the end of the ablation

Transhepatic echocardiography: a novel approach for imaging in left ventricle assist device patients with difficult acoustic windows

Aims A significant proportion of left ventricle assist device (LVAD) patients have very difficult transthoracic echocardiographic images. The aim of this study was to find an echocardiographic window which would provide better visualization of the heart in LVAD patients with limited acoustic windows. ................................................................................................................................................................................................... Methods and results Based on the anatomic relationships in LVAD patients, a right intercostal transhepatic approach was proposed. By using a computer simulator, we searched for the appropriate probe orientation. Further, 15 ambulatory LVAD patients (age 56 ± 15 years, 73% males) underwent two echocardiographic studies: one normal transthoracic echocardiography following the institutional protocol (Echo 1) and a second study which included the transhepatic approach (Echo 2). The two exams were performed by two different sonographers and the results validated by a third observer for agreement. The transhepatic intercostal window was feasible in all patients, with an image quality allowing good visualization of structures in 93%. Precise quantification of the left ventricular (LV) and right ventricular (RV) function was achieved more often in the Echo 2 (10 vs. 3 patients for LV, P = 0.03 and 14 vs. 8 patients for RV, P = 0.04). A significant difference existed also in the quantification of the LVAD inflow cannula flow by pulsed Doppler (11 patients in Echo 2 vs. 3 patients in Echo 1, P = 0.009). ................

Determinants of changes in pulmonary artery pressure in patients with severe aortic stenosis treated by tr

Background: Elevated pulmonary artery pressure (PAP) in patients with severe aortic stenosis (AS) is a strong predictor of adverse prognosis. This study sought to assess the relation between PAP and clinical and echocardiographic parameters in elderly patients with severe AS, as well as to identify the determinants of the change in PAP after transcatheter aortic valve implantation (TAVI). Methods: The study included 170 subjects (age 81 ± 7 years, 45% men) with symptomatic severe AS who were treated by TAVI. They underwent a clinical evaluation and a transthoracic echocardiography before the TAVI procedure and 6 months after. Results: In a multivariable analysis, the independent predictors for baseline PAP were the body mass index (BMI) (β = 0.21, p =.006), COPD GOLD class (β = 0.20; p =.009), the E/e′ ratio (β = 0.20; p =.02) and the degree of aortic regurgitation (β = 0.20; p =.01). After TAVI, there was significantly less (51% vs. 29%, p<.0001) pulmonary hypertension, defined as a tricuspid regurgitation velocity ≥2.8 m/s. The baseline variables related to an improvement in PAP were the tricuspid regurgitation velocity (p =.0001) and the E/e′ (p =.005). From the parameters potentially modified with TAVI, the only independent predictor of PAP variation was the change in the E/e′ ratio (β = 0.23; p =.01). Conclusions: Independent predictors for baseline PAP in elderly patients with symptomatic AS were the BMI, GOLD class, the aortic regurgitation and the E/e′ ratio. The baseline predictors for a change in PAP 6 months after TAVI were the baseline PAP and E/e′, with only the change in the E/e′ ratio being correlated to the change in PAP

Cardiac Shear Wave Elastography Using a Clinical Ultrasound System

The propagation velocity of shear waves relates to tissue stiffness. We prove that a regular clinical cardiac ultrasound system can determine shear wave velocity with a conventional unmodified tissue Doppler imaging (TDI) application. The investigation was performed on five tissue phantoms with different stiffness using a research platform capable of inducing and tracking shear waves and a clinical cardiac system (Philips iE33, achieving frame rates of 400-700 Hz in TDI by tuning the normal system settings). We also tested the technique in vivo on a normal individual and on typical pathologies modifying the consistency of the left ventricular wall. The research platform scanner was used as reference. Shear wave velocities measured with TDI on the clinical cardiac system were very close to those measured by the research platform scanner. The mean difference between the clinical and research systems was 0.18 ± 0.22 m/s, and the limits of agreement, from -0.27 to +0.63 m/s. In vivo, the velocity of the wave induced by aortic valve closure in the interventricular septum increased in patients with expected increased wall stiffness

Extending education to the Pacific region through cohort teaching - science teachers accelerated programme

The left atrial septal pouch (LASP) is formed by incomplete fusion of the septum primum and septum secundum, leaving a cavity open towards the left atrium, but without interatrial shunting. There is no recommendation concerning strategy in the presence of a LASP, especially in the setting of stroke. The aim of this review was to determine whether the LASP could be incriminated as the aetiology of a stroke. We included all pertinent publications on the subject, an

The role of experience in echocardiographic identification of location and extent of mitral valve prolapse with 2D and 3D echocardiography

Contradiction exists on the incremental value of two-dimensional (2D) and 3D transoesophageal echocardiography (TOE) over 2D transthoracic echocardiography (TTE) for the detection of mitral valve (MV) prolapse in readers with different echocardiographic experience. Twenty patients and five healthy persons were retrospectively identified who had undergone 2D-TTE, 2D-TOE and 3D-TOE. Fifteen (75 %) patients had surgical evidence of prolapse of the posterior MV leaflet and five patients (25 %) had a dilated MV annulus without prolapse. Three reader groups with different echocardiographic expertise (novice, trainees, cardiologists) scored thus in total 675 posterior scallops. Overall there was an improvement in agreement and Kappa values from novice to trainees to cardiologists. Diagnostic accuracies of 2D-TOE were higher than those of 2D-TTE mainly in novice readers. The incremental value of 3D-TOE over 2D-TOE was mainly seen in specificities. Time to diagnosis was dramatically reduced from 2D to 3D-TEE in all reader groups (all P < 0.001). 3D-TOE also improved the agreement (+12 to +16 %) and Kappa values (+0.14 to +0.21) in all reader groups for the exact description of P2 prolapse. Differences between readers with variable experience in determining the precise localization and extent of the prolapsing posterior MV scallops exist in particular in 2D-TTE analysis. 3D-TOE analysis was extremely fast compared to the 2D analysis methods and showed the best diagnostic accuracy (mainly driven by specificity) with identification of P1 and P3 prolapse still improving from novice to trainees to cardiologists and provided optimal description of P2 prolapse extent

Prognostic value of temporal patterns of left atrial reservoir strain in patients with heart failure with reduced ejection fraction

Background: We investigated whether repeatedly measured left atrial reservoir strain (LASr) in heart failure with reduced ejection fraction (HFrEF) patients provides incremental prognostic value over a single baseline LASr value, and whether temporal patterns of LASr provide incremental prognostic value over temporal patterns of other echocardiographic markers and NT-proBNP. Methods: In this prospective observational study, 153 patients underwent 6-monthly echocardiography, during a median follow-up of 2.5 years. Speckle tracking echocardiography was used to measure LASr. Hazard ratios (HRs) were calculated for LASr from Cox models (baseline) and joint models (repeated measurements). The primary endpoint (PEP) comprised HF hospitalization, left ventricular assist device, heart transplantation, and cardiovascular death. Results: Mean age was 58 ± 11 years, 76% were men, 82% were in NYHA class I/II, mean LASr was 20.9% ± 11.3%, and mean LVEF was 29% ± 10%. PEP was reached by 50 patients. Baseline and repeated measurements of LASr (HR per SD change (95% CI) 0.20 (0.10–0.41) and (0.13 (0.10–0.29), respectively) were both significantly associated with the PEP, independent of both baseline and repeated measurements of other echo-parameters and NT-proBNP. Although LASr was persistently lower over time in patients with PEP, temporal trajectories did not diverge in patients with versus without the PEP as the PEP approached. Conclusion: LASr was associated with adverse events in HFrEF patients, independent of baseline and repeated other echo-parameters and NT-proBNP. Temporal trajectories of LASr showed decreased but stable values in patients with the PEP, and do not provide incremental prognostic value for clinical practice compared to single measurements of LASr. Graphical abstract: [Figure not available: see fulltext.].</p