Bicuspid aortic valve disease associates with abnormal wall shear stress, viscous energy loss, and pressure drop within the ascending thoracic aorta

Introduction

We use 4D Flow MRI to (1) investigate the effects of bicuspid aortic valve (BAV) disease on downstream pressure drop (PD), wall shear stress (WSS), and viscous energy loss (EL) in the ascending aorta (AAo) and (2) explore the associations between AAo diameter and PD, WSS, and EL.

Hypothesis

BAV patients show increased PD, WSS, and EL in the AAo compared to age-matched controls

Methods

32 healthy controls (41±15 y, 10 female) and 53 BAV patients (44±16 y, 19 female) underwent cardiac MRI at 3T, inclusive of cine imaging and 4D flow. Cross sections were placed along segmented aortas at the: left ventricular outflow tract (LVOT), sinuses of Valsalva (SOV), mid-ascending aorta (MAA), and proximal to first aortic branch (AA1). Locations were analyzed for (i) net flow, (ii) aortic diameter (normalized to BSA), (iii) systolic PD (referenced to LVOT), (iv) systolic EL (measured within LVOT-AA1 volume and normalized by LVOT net flow; mW/mL), and (v) systolic WSS. Sub-vectors of WSS, axial (WSSax) and circumferential (WSScirc), were also analyzed.

Results

In comparison to controls, BAV patients showed greater PD (e.g. MAA: 9.5±8.0 vs. 2.8±2.4mmHg; p<0.01), EL (0.09±0.05 vs. 0.04±0.01 mW/mL; p≤0.01), and WSScirc (e.g. MAA: 0.3±0.1 vs. 0.2±0.06 Pa; p≤0.01) throughout the AAo (Table 1 and Fig. 1). BAV patients exhibited significantly lower WSS and WSSax only at the SOV. In univariate analyses, AAo diameter was inversely correlated with WSS (R=−0.32, p<0.01) and WSSax (R=−0.51, p≤0.01). In multivariate analyses, AAo diameter was associated with WSS (β=−0.36, p<0.01) and WSSax (β=−0.26, p<0.01).

Conclusions

BAV patients demonstrate significantly increased PD, EL, and WSScirc in the AAo, and an inverse association between AAo diameter and WSS measures.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Alberta Health Services

Lessons for the clinical nephrologist: a rare case of unfused renal ectopia

Right crossed inferior unfused renal ectopia is a rare developmental anomaly in which both kidneys are located on the left side of the body. It's the result of a halt in migration of kidneys to their normal location during the embryonic period and in ureteral bud faulty that migrates to the opposite side and induces the metanephric blastema on the wrong side. In this article, we aim to review embryology and complete description of renal ectopia anatomy and describe a rare case of right crossed unfused inferior renal ectopia with a left lower kidney artery originated directly from an abdominal aortic aneurism (AAA). The treatment consisted in AAA's exclusion with a custom-made endograft device shaped on purpose with a dedicated branch allowing perfusion of the ectopic lower left kidney.

Truncated Nonlinear Interferometry for Quantum-Enhanced Atomic Force Microscopy

Nonlinear interferometers that replace beam splitters in Mach-Zehnder interferometers with nonlinear amplifiers for quantum-enhanced phase measurements have drawn increasing interest in recent years, but practical quantum sensors based on nonlinear interferometry remain an outstanding challenge. Here, we demonstrate the first practical application of nonlinear interferometry by measuring the displacement of an atomic force microscope microcantilever with quantum noise reduction of up to 3 dB below the standard quantum limit, corresponding to a quantum-enhanced measurement of beam displacement of 1.7  fm/sqrt[Hz]. Further, we minimize photon backaction noise while taking advantage of quantum noise reduction by transducing the cantilever displacement signal with a weak squeezed state while using dual homodyne detection with a higher power local oscillator. This approach may enable quantum-enhanced broadband, high-speed scanning probe microscopy.

126Dynamic high density functional substrate mapping improves outcomes in ventricular tachycardia ablation

Introduction

Activation and entrainment mapping of VT remains the gold standard for identifying critical sites for ablation of VT, however, this method is limited by poorly tolerated or non-sustained VT. Several substrate guided approaches have been developed, however, outcomes when comparing both methods are similar and overall success can be as low as 47%. A key element in facilitating VT is the presence of dynamic changes within the substrate which may not be evident during sinus rhythm substrate mapping, but may form a critical aspect of the tachycardia mechanism when conduction velocity slows dynamically and tissue refractory periods lengthen. These are rarely studied as part of clinical VT mapping. 

Purpose

This study aimed to investigate dynamic substrate changes to local abnormal ventricular activity (LAVA) and late potentials (LP), in relation to critical sites for VT ablation using high resolution mapping of the ventricle with the HD Grid (Abbott, Inc, USA), during short coupled singe extra stimuli from the right ventricle (RV) (Barts Sense Protocol), designed to invoke conduction delay. We hypothesized that the dynamic functional late potential mapping would improve the identification of critical substrate and ablation of these regions would improve outcomes. 

Methods

Thirty patients (age 67 +/- 9yrs, 27Male) underwent ablation. Mean ejection fraction was 25% (+/- 10%). Mapping was performed with the AdvisorTM HD Grid multipolar catheter. A bipolar voltage map was obtained during sinus rhythm (SR) and RV Sensed Protocol (SP) single extra pacing. SR and SP late potential (LP) and local abnormal ventricular activity (LAVA) maps were made and compared with critical sites for ablation, defined as sites of best entrainment or pace mapping. Ablation was then performed to critical sites and LP/LAVA identified by the SP.

Results

At a median follow up of 10 months 90% of patients were free from symptomatic ATP or ICD shocks. The median area of late potentials across the 30 patients during sinus rhythm was 6.4mm2 during sinus rhythm mapping and 19.3mm2 during sense protocol pacing (p = 0.001). The functional unmasking of LP and LAVA was seen in 26 patients and showed good correlation to critical regions of the VT circuit (sites of best entrainment or pace map). In 24 patients functionally unmasked late potentials were located within 10mm of critical regions within the mapped VT circuit, with a median distance of 8.5mm, compared to 7 patients during sinus rhythm mapping with a median distance of 22mm (p= <0.001). Figure 1 demonstrates and example of the SP, where increased functional LP are seen along the mapped VT isthmus. 

Conclusion

Functional LP and LAVA can be unmasked by the sense protocol enabling better delineation of critical regions for VT ablation which may not be visible during sinus rhythm. This unique delineation of functional substrate changes combined with activation or pacemapping may improve outcomes.

Abstract Figure 1

THU0053 CONTRIBUTION OF DEFECTIVE NON-APOPTOTIC FAS SIGNALING TO IMMUNE DYSREGULATION IN AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME (ALPS)

Background:

ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.

Objectives:

We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.

Methods:

We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.

Results:

In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.

Conclusion:

We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.

Disclosure of Interests:

None declared

1102 Relationship Between Emotional Distress And Sleep Duration Among Hispanics Using The 2018 National Health Interview Survey Dataset

Introduction

Although Hispanics experience a high level of shorter sleep duration (< 7 hrs./24 period), a clear mechanism or cause is lacking. Previous research indicate that emotional distress may explain the burden of shorter sleep among blacks. Applying these findings to Hispanics, we investigated whether emotional distress explains the burden of short sleep duration (< 7 hrs.) among Hispanics and if this relationship varies by sex

Methods

We used data from the 2018 National Health Interview Survey (NHIS) dataset, a nationally representative sample, in which only Hispanic ethnicity participants (N=3,091) were analyzed. Average sleep duration was self-reported and measured in hours. Emotional distress was measured using Kessler 6, which measures how an individual felt over the past 30 days: nervous, hopeless, restless/fidgety, depressed, effortful and worthless. To assess the association between short sleep duration and emotional distress, we performed Pearson correlation, hierarchical regression analyses, and stratified this relationship by sex to determine if this relationship differed between males and females, adjusting for covariates.

Results

Of the total sample of 3,091 Hispanics, 1,762 were female, and 1,329 were male. Sleep duration and emotional distress were negatively correlated among females (r = -.27, p <.001) and males (r=-.18, p <.001). Among Hispanic females, sleep duration significantly predicted emotional distress, β = -.27, t = -11.60, p <.001, and explained a significant portion of variance in emotional distress, R2 = .07, F= 134.63, p <.001. While, among Hispanic males, sleep significantly predicted emotional distress (β = -.18, t =-6.5, p <.001) and explained a significant portion of the variance in emotional distress (R2 = .03, F= 42.37, p <.001).

Conclusion

Our findings indicate that a negative sleep-ED relationship, suggesting that shorter sleep was predictive of higher levels of emotional distress among Hispanics and that this relationship is greater among Hispanic females, compared males.

Support

K01HL135452, R01MD007716, R01HL142066, and K07AG052685

1189 Recruiting, Training, And Implementing Sleep Health Educators In Community-based Research To Improve Sleep Health

Introduction

Adherence to OSA assessment and treatment is low among racial/ethnic minorities, particularly among blacks. Navigating patients along the continuum of care from assessment to treatment adherence requires motivation, social support, and self-efficacy. Previous studies indicate that community health educators can provide motivation, social support, and skills to patients to better navigate the complex OSA care continuum. However, recruiting, training, and implementing sleep health educators in clinical or research settings is complex. For the current study, we describe how we recruit, train, and implement sleep health educators in research and clinical settings and assess what makes a sleep health educator successful.

Methods

We recruited and trained twenty-five self-identified black sleep health educators for a randomized clinical trial (R01MD007716) focused on increasing OSA assessment and treatment adherence among blacks. During recruitment, we assessed key personality attributes that translate to being an effective sleep health educator, via behavioral and personality surveys, focused groups, and process forms filled out by educators. Sleep health educators underwent an 8-week training program on sleep health and motivational interviewing. In order to be certified, sleep health educators had to pass a written and scenario-based assessment. During the implementation phase of the trial, we assessed how many interviews each health educator conducted and whether individual characteristics were related to how many interviews.

Results

Of the trained educators, 80% were female, ranging from 25 to 58 years old. They all completed at least high school. All educators rated the program highly and were very satisfied with dispensing tailored sleep health education. Educators who displayed the highest knowledge about sleep health, provided frequent emotional and strategic support, committed to helping their assigned participants, and who rated their rapport highly with their assigned participants were most effective in getting their participant to adhere to OSA assessment and treatment.

Conclusion

Sleep health educators can be vital to increasing OSA assessment and treatment adherence among blacks. In order to ensure success, sleep health educators must undergo a thorough recruitment, training, and implementation and dissemination process.

Support

K01HL135452, R01MD007716, R01HL142066, K01HL135452,and K07AG052685

0078 Influence of Light on Brain Activity Upon Waking From Slow Wave Sleep

Introduction

Waking from sleep is associated with reduced alertness due to sleep inertia. Light acutely improves alertness during sleep deprivation. In this study we assessed the influence of light on brain activity and connectivity after waking from slow wave sleep (SWS).

Methods

Twelve participants kept an actigraphy-confirmed stable sleep schedule with 8.5 hours for five nights and five hours for one night prior to an overnight laboratory visit. Participants completed two three-minute Karolinska Drowsiness Tests (KDT) before going to bed at their habitual bedtime. They were monitored continuously using high-density EEG (32-channel; Brain Products GmbH). Participants were woken twice and exposed to red light (0.01 melanopic-lux; control) or blue-enriched light (63.62 melanopic-lux) for one hour, in a randomized order, following at least five minutes of SWS. EEG artifact were removed algorithmically and the spectral composition of each electrode (i.e., fast fourier transform, FFT) and effective connectivity (i.e., partial directed coherence, PDC) between each electrode were estimated. A graphical analysis was conducted to extract features relevant to the facilitation of efficient communication between electrodes. All data were averaged within frequency bins of interest that correspond to delta (1-3Hz), theta (4-7Hz), alpha (8-12Hz), and beta (13-25Hz) bands and expressed relative to the pre-sleep baseline.

Results

Compared to the pre-sleep baseline, participants exposed to blue-enriched light experienced reduced theta and alpha activity; however, these results were not significantly different from the control. In contrast, the communication of frontal electrodes significantly increased across all frequency bands compared to the control, and this effect was most prominent in the alpha (t(11)=3.80, p=.005) and beta bands (t(11)=3.92, p=.004).

Conclusion

Exposure to blue-enriched light immediately after waking from SWS may accelerate the process of waking and help to improve alertness by facilitating communication between brain regions. Future analyses will explore the temporal persistence and granularity of the communicative properties associated with this response.

Support

Naval Postgraduate School Grant. NASA Airspace Operations and Safety Program, System-Wide Safety Project.

Outcome of ACHD patients with non-inducible versus inducible IART undergoing cavo-tricuspid isthmus ablation: the role of empiric ablation

PURPOSE

Catheter ablation for supraventricular tachycardia (SVT) in adults with congenital heart disease (ACHD) is an important therapeutic option. Cavo-tricuspid isthmus (CTI)-dependent intraatrial re-entrant tachycardia (IART) is common. However, induction of sustained tachycardia at the time of ablation is not always possible. We hypothesised that performing an empiric CTI line in case of non-inducibility leads to good outcomes. Long-term outcomes of empiric versus entrained CTI ablation in ACHD patients were examined.

METHODS

Retrospective, single-centre, case-control study over 7 years. Arrhythmia-free survival after empiric versus entrained CTI ablation was compared.

RESULTS

Eighty-seven CTI ablations were performed in 85 ACHD patients between 2010 and 2017. The mean age of the cohort was 43 years and 48% were male. Underlying aetiology included ASD (31%), VSD (11.4%), AVSD (9.1%), AVR (4.8%), Fallot's (18.4%), Ebstein's (2.3%), Fontan's palliation (9.2%) and atrial switch (13.8%). CTI-dependent IART was entrained in 59 patients whereas it was non-inducible in 28. The latter had an empiric CTI ablation. Forty-three percent of procedures were performed under general anaesthesia. There were no reported procedural complications. There was no significant difference in the mean procedure or fluoroscopy times between the groups (empiric vs entrained CTI; 169.1 vs 183.3 and 28.1 vs 19.9 min). Arrhythmia-free survival was 64.3% versus 72.8% (p value 0.44) in the empiric and entrained groups at 21 months follow-up.

CONCLUSIONS

Long-term outcomes after empiric and entrained CTI ablation for IART in ACHD patients are comparable. This is a safe and effective therapeutic option. In the case of non-inducibility of IART, an empiric CTI line should be considered in this cohort.

Determination of Fluoride in Wine by Fluoride Selective Ion Electrode, Standard Addition Method: Collaborative Study

The accuracy, precision, and reproducibility of a rapid method for determination of fluoride in wine, using a fluoride selective ion electrode, were established by a collaborative study involving 12 laboratories, 5 in Europe and 7 in the United States. The laboratories assayed 6 Youden pairs of fluo-ride-fortified, red and white wine samples with fluoride concentrations ranging from 0.2 to 3.0 mg/L. The relative standard deviations of repeatability ranged from 1.94 to 4.88%; relative standard deviations of reproducibility ranged from 4.15 to 18.40%. HORRAT values ranged from 0.30 to 0.97. The average recovery was 99.97%. Based on the statistical results of this collaborative study, the Study Director recommends that this method be adopted First Action.