Combining Automatic Angle Correction and 3-D Tracking Doppler for the Assessment of Aortic Stenosis Severity

Aortic valve stenosis (AS) is a narrowing of the aortic valve opening, which causes increased load on the left ventricle. Untreated, this condition can eventually lead to heart failure and death. According to current recommendations, an accurate diagnosis of AS mandates the use of multiple acoustic windows to determine the highest velocity. Furthermore, the optimal positioning of both patient and transducer to reduce the beam-to-flow angle is emphasized. Being operator dependent, the beam alignment is a potential source of uncertainty. In this work, we perform noncompounded 3-D plane wave imaging for retrospective estimation of maximum velocities in aortic jets with automatic angle correction. This is achieved by combining a hybrid 3-D speckle tracking method to estimate the jet direction and 3-D tracking Doppler to generate angle-corrected sonograms, using the direction from speckle tracking as input. Results from simulations of flow through an orifice show that 3-D speckle tracking can estimate the jet orientation with acceptable accuracy for signal-to-noise ratios above 10 dB. Results from 12 subjects show that sonograms recorded from a standard apical view using the proposed method yield a maximum velocity that matches continuous wave (CW) Doppler sonograms recorded from the acoustic window with the lowest angle within a ±10% margin, provided that a high enough pulse repetition frequency could be achieved. These results motivate further validation and optimization studies

Examining the educational impact of the mini-CEX: a randomised controlled study

Background: The purpose of this study is to evaluate the mini-Clinical Evaluation Exercise (mini-CEX) as a formative assessment tool among undergraduate medical students, in terms of student perceptions, effects on direct observation and feedback, and educational impact. Methods: Cluster randomised study of 38 fifth-year medical students during a 16-week clinical placement. Hospitals were randomised to provide a minimum of 8 mini-CEXs per student (intervention arm) or continue with ad-hoc feedback (control arm). After finishing their clinical placement, students completed an Objective Structured Clinical Examination (OSCE), a written test and a survey. Results: All participants in the intervention group completed the pre-planned number of assessments, and 60% found them to be useful during their clinical placement. Overall, there were no statistically significant differences between groups in reported quantity or quality of direct observation and feedback. Observed mean scores were marginally higher on the OSCE and written test in the intervention group, but not statistically significant. Conclusions: There is considerable potential in assessing medical students during clinical placements and routine practice, but the educational impact of formative assessments remains mostly unknown. This study contributes with a robust study design, and may serve as a basis for future research

Implantasjon av hjertestartere ved St. Olavs hospital 2006–15

BAKGRUNN Implantasjon av hjertestarter (implantable cardioverter defibrillator, ICD) er etablert behandling hos pasienter med høy risiko for plutselig hjertedød. Studiens formål var å kartlegge pasientkarakteristika, indikasjoner, hyppigheten av ICD-støt, komplikasjoner, reoperasjoner samt endringer over tid i ICD-behandlingen ved St. Olavs hospital. MATERIALE OG METODE Alle pasienter som fikk implantert hjertestarter ved St. Olavs hospital i perioden 2006–15 ble inkludert. Pasientene ble identifisert i pacemakerregisteret. Data ble hentet fra pacemakerregisteret og elektronisk pasientjournal. RESULTATER Studien inkluderte 598 pasienter (82 % menn, medianalder 65 år). Tidligere hjertestans eller alvorlig arytmi forelå hos 401 (67 %) av dem som fikk implantert hjertestarter. Koronarsykdom (n = 383) var vanligste underliggende årsak. I oppfølgingstiden (median 3,6 år) fikk 203 (34 %) av pasientene ICD-støt, 154 (26 %) fikk berettigede og 65 (11 %) fikk uberettigede støt. Hos 139 (23 %) pasienter oppstod komplikasjoner. 101 (17 %) pasienter døde i oppfølgingsperioden. FORTOLKNING Studien gir et godt grunnlag for kvalitetssikring av implantasjonsvirksomheten ved St. Olavs hospital. Kjønns- og aldersfordeling, indikasjon og underliggende årsaker for implantasjon samt hyppighet av støt og komplikasjoner samsvarer godt med tidligere publiserte data

Implantasjon av hjertestartere ved St. Olavs hospital 2006–15

BAKGRUNN Implantasjon av hjertestarter (implantable cardioverter defibrillator, ICD) er etablert behandling hos pasienter med høy risiko for plutselig hjertedød. Studiens formål var å kartlegge pasientkarakteristika, indikasjoner, hyppigheten av ICD-støt, komplikasjoner, reoperasjoner samt endringer over tid i ICD-behandlingen ved St. Olavs hospital. MATERIALE OG METODE Alle pasienter som fikk implantert hjertestarter ved St. Olavs hospital i perioden 2006–15 ble inkludert. Pasientene ble identifisert i pacemakerregisteret. Data ble hentet fra pacemakerregisteret og elektronisk pasientjournal. RESULTATER Studien inkluderte 598 pasienter (82 % menn, medianalder 65 år). Tidligere hjertestans eller alvorlig arytmi forelå hos 401 (67 %) av dem som fikk implantert hjertestarter. Koronarsykdom (n = 383) var vanligste underliggende årsak. I oppfølgingstiden (median 3,6 år) fikk 203 (34 %) av pasientene ICD-støt, 154 (26 %) fikk berettigede og 65 (11 %) fikk uberettigede støt. Hos 139 (23 %) pasienter oppstod komplikasjoner. 101 (17 %) pasienter døde i oppfølgingsperioden. FORTOLKNING Studien gir et godt grunnlag for kvalitetssikring av implantasjonsvirksomheten ved St. Olavs hospital. Kjønns- og aldersfordeling, indikasjon og underliggende årsaker for implantasjon samt hyppighet av støt og komplikasjoner samsvarer godt med tidligere publiserte data

3D Myocardial Mechanical Wave Measurements: Toward In Vivo 3D Myocardial Elasticity Mapping

Objectives This study aimed to investigate the potential of a novel 3-dimensional (3D) mechanical wave velocity mapping technique, based on the natural mechanical waves produced by the heart itself, to approach a noninvasive 3D stiffness mapping of the left ventricle. Background Myocardial fibrosis is recognized as a pathophysiological substrate of major cardiovascular disorders such as cardiomyopathies and valvular heart disease. As fibrosis leads to increased myocardial stiffness, ultrasound elastography measurements could provide important clinical information. Methods A 3D high frame rate imaging sequence was implemented on a high-end clinical ultrasound scanner to achieve 820 volumes/s when gating over 4 consecutive cardiac cycles. Five healthy volunteers and 10 patients with various degrees of aortic stenosis were included to evaluate feasibility and reproducibility. Mechanical waves were detected using the novel Clutter Filter Wave Imaging approach, shown to be highly sensitive to the weak tissue displacements caused by natural mechanical waves. Results 3D spatiotemporal maps of mechanical wave velocities were produced for all subjects. Only the specific mechanical wave at atrial contraction provided a full 3D coverage of the left ventricle (LV). The average atrial kick propagation velocity was 1.6 ± 0.2 m/s in healthy volunteers and 2.8 ± 0.8 m/s in patients (p = 0.0016). A high correlation was found between mechanical wave velocity and age (R2 = 0.88, healthy group), septal wall thickness (R2 = 0.73, entire group), and peak jet velocity across the aortic valve (R2 = 0.70). For 3 of the patients, the higher mechanical wave velocity coexisted with the presence of late gadolinium enhancement on cardiac magnetic resonance. Conclusions In this study, 3D LV mechanical wave velocities were visualized and measured in healthy volunteers and patients with aortic stenosis. The proposed imaging sequence and measurement technique allowed, for the first time, the measurement of full spatiotemporal 3D elasticity maps of the LV using ultrasound. (Ultrasonic markers for myocardial fibrosis and prognosis in aortic stenosis; NCT03422770

Automatic measurements of left ventricular volumes and ejection fraction by artificial intelligence: clinical validation in real time and large databases

Aims - Echocardiography is a cornerstone in cardiac imaging, and left ventricular (LV) ejection fraction (EF) is a key parameter for patient management. Recent advances in artificial intelligence (AI) have enabled fully automatic measurements of LV volumes and EF both during scanning and in stored recordings. The aim of this study was to evaluate the impact of implementing AI measurements on acquisition and processing time and test–retest reproducibility compared with standard clinical workflow, as well as to study the agreement with reference in large internal and external databases. Methods and results - Fully automatic measurements of LV volumes and EF by a novel AI software were compared with manual measurements in the following clinical scenarios: (i) in real time use during scanning of 50 consecutive patients, (ii) in 40 subjects with repeated echocardiographic examinations and manual measurements by 4 readers, and (iii) in large internal and external research databases of 1881 and 849 subjects, respectively. Real-time AI measurements significantly reduced the total acquisition and processing time by 77% (median 5.3 min, P Conclusion - The software reduced the time taken to perform and volumetrically analyse routine echocardiograms without a decrease in accuracy compared with experts

Automatic measurements of left ventricular volumes and ejection fraction by artificial intelligence reduces time-consumption and inter-observer variability

Poster presentation at the international EACVI conference, 10.05.23 - 12.05.23, Barcelona, Spain