Percutaneous coronary intervention is performed routinely in the management of myocardial infarction with obstructive coronary disease, but intervention to arteries supplying nonviable myocardium may ...be harmful. It is important therefore to establish myocardial viability, and there is an unmet need in current clinical practice for real time viability assessment to aid in decision making. Transcoronary pacing to assess myocardial electrophysiological parameters may be a novel viability assessment technique which could be used in this regard.
Coronary intervention was carried out according to standard departmental procedure with standard equipment. An exchange length coronary guidewire was passed into both target and reference coronary vessels and an over-the-wire balloon or microcatheter was used to insulate the guidewire and allow electrophysiological parameters to be assessed. Readings were obtained from all major epicardial vessels and substantial branches. At each position, an intracoronary electrocardiogram was recorded, and R wave amplitude was measured. Transcoronary pacing was then performed to establish threshold and impedance for each myocardial segment. A viability cardiac MRI scan was performed for each patient. A standard segmental model was used to determine viability in each segment using an 'infarct score' based on degree of late gadolinium enhancement. Studies were reported blinded to the electrical parameters obtained from the coronary guidewire. The primary outcome was the relationship between pacing threshold and myocardial segment infarct score. Secondary outcomes included the relationship between segmental infarct score and R wave height, and between segmental infarct score and pacing impedance. Data were collected on the feasibility of studying the coronary segments as well as safety.
Sixty-five patients presenting with stable coronary artery disease or acute coronary syndromes to Leeds General Infirmary between September 2019 and August 2021 were included in the study. Electrophysiological parameters from segments with an infarct score of zero were obtained, with wide variances seen, with no significant difference in impedance or threshold in any territory. There was a significant difference in sensitivity for segments in the right coronary artery territory for both elective and acute patients. This likely relates to reduced myocardial mass in these territories. No significant association between infarct score and sensitivity, impedance or threshold were seen.
This study has established intracoronary electrophysiological parameters in both normal myocardium and areas of myocardial scar. No reliable association was seen between impedance, threshold or R wave amplitude and degree of myocardial viability, contrasting with prior findings from our group and others. More work is therefore required to fully understand the role of transcoronary pacing in this setting.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Anti-tachycardia pacing (ATP) is frequently used to terminate ventricular tachycardia (VT), however it is not always successful and may accelerate VT requiring defibrillation. REVRAMP is a novel ...concept of ATP that involves delivering pacing at a faster rate than VT, but instead of abruptly terminating pacing after eight beats, pacing is gradually slowed until VT continues or normal rhythm is restored. In a pilot study we show that REVRAMP can restore normal rhythm, and that if REVRAMP is unsuccessful, VT is not accelerated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To monitor for drug-related cardiac arrhythmias, psychiatrists regularly perform and interpret 12-lead (12L) and, increasingly often, six-lead (6L) electrocardiograms (ECGs). It is not known how ...training on this complex skill is updated or how well psychiatrists can interpret relevant arrhythmias on either device. We conducted an online survey and ECG interpretation test of cardiac rhythms relevant to psychiatrists. A total of 183 prescribers took part; 75% did not regularly update their ECG interpretation skills, and only 22% felt confident in interpreting ECGs. Most participants were able to recognise normal ECGs. For both 6L and 12L ECGs, the majority of participants were able to recognise abnormal ECGs, but fewer than 50% were able to correctly identify relevant arrhythmias (complete heart block and long QTc). A small number prescribed in the presence of potentially fatal arrhythmias. These findings suggest a need for mandatory ECG interpretation training to improve safe prescribing practice.
Previous reports have documented the coexistence of obstructive sleep apnea (OSA) and epilepsy and the therapeutic effects of treatment on seizure frequency and daytime sleepiness. The authors' ...objective was to determine the prevalence of OSA and its association with survey items in a group of patients with medically refractory epilepsy undergoing polysomnography (PSG).
Thirty-nine candidates for epilepsy surgery without a history of OSA underwent PSG as part of a research protocol examining the relationship of interictal epileptiform discharges to sleep state. Subjects also completed questionnaires about their sleep, including validated measures of sleep-related breathing disorders (Sleep Apnea Scale of the Sleep Disorders Questionnaire SA/SDQ) and subjective daytime sleepiness (Epworth Sleepiness Scale ESS).
One-third of subjects had OSA, defined by a respiratory disturbance index (RDI) > or = 5. Five subjects (13%) had moderate to severe OSA (RDI > 20). Subjects with OSA were more likely to be older, male, have a higher SA/SDQ score, and more likely to have seizures during sleep than those without OSA (p < 0.05). Seizure frequency per month, the number or type of antiepileptic drugs (AED) prescribed, the localization of seizures (temporal versus extratemporal), and the ESS were not statistically different between the two groups.
In our sample, previously undiagnosed obstructive sleep apnea was common, especially among men, older subjects, and those with seizures during sleep. The impact of treating OSA on seizure frequency and daytime sleepiness in medically refractory epilepsy patients warrants further controlled study.
As the wide-scale use of uncrewed aerial systems, or UAS, proceeds towards civilian airspace, guarantees of operational safety over the entire flight envelope become more critical. However, public ...opinion is mixed on the general safety of autonomous systems, especially within close proximity to densely populated spaces. Because the opinion of the general public is of paramount importance to the general adoption of this technology, focus must be placed on the development of dependable systems before operations can even be considered.With the stringent payload capacity and size constraints of UAS, advanced control algorithms can fill the gap caused by the reduced redundancy expected of UAS. One such branch of control algorithms is active fault tolerant control, which uses knowledge of failures to update the control loop and maintain performance. However, most works on active fault tolerant control present in literature trivialize fault detection and diagnosis to hard to achieve assumptions of perfect knowledge of failures or the presence of actuator feedback systems, which are currently not widely used. These weight and cost penalties increases the appeal of a software-based system for fault detection, which solely uses measurements from sensors already necessary for autonomous flight, completely eliminating the disadvantages of hardware-based systems.As system dynamics change during failures, system identification is an intuitive way to measure changes in dynamics to estimate actuation failures, especially flight-critical actuators which have a large impact on system performance. In this work, a time domain system identification method based on the eigensystem realization algorithm (ERA) and observer Kalman filter identification method (OKID) is used. These methods used in tandem can generate a model capturing the maximum input-output information from any arbitrary set of data, providing a more generalizable approach than is possible with most system identification techniques. Taking advantage of available flight tests data which contained aileron and rudder failure cases, this combination is applied to flight test data, and the models generated are used to investigate the change in dynamics present during failures, with changes in model parameters correlated to failures.Knowledge of failures can be leveraged by the control loop by an adaptive flight controller if the dynamic model of the aircraft is available after failure. This research presents applications of two different control algorithms capable of adapting to changing dynamic models, model predictive control (MPC) and dynamic inversion. This work adds a non-traditional control increment term, ∆u, to the MPC cost function to directly punish large control rates to prevent oscillations and out of phase behavior. The presented dynamic inversion flight controller allows for a more direct approach to system performance design. Its theory implies the ability to maintain performance in the case of faults as long as adequate updates to the model are provided and enough overall control authority is available to make the commanded maneuvers.Typical approaches to simulation validation of fault tolerant control methods are based heavily in assumptions on how failures impact the dynamic model. In direct contrast to this, validation models for this work are based on collected failure flight test data and generated using a Monte Carlo-based technique. This method varies model parameters based on a given normal distribution to find a dynamic model which best fits the measured aircraft states. Nominal simulations results show a similar level of performance of both control algorithms, while failure simulations highlight the satisfactory performance of both controllers as well as the different benefits offered by each algorithm.This work builds off of a previously published conference paper which presents preliminary results of the fault detection method with one data set and only performs failure validation simulation for the LQR and dynamic inversion controllers.
This paper presents the flight test verification and validation of a novel multi-reference longitudinal and lateral-directional guidance logic across multiple autonomous aircraft with distinctly ...different dynamics. L
N
guidance logic takes advantage of tracking a span of multiple references across the desired track, similar to an insect’s compound eyes, allowing for a much higher temporal resolution and more predictive and anticipatory guidance logic. The stability of L
N
guidance algorithms is investigated using global Lyapunov stability theorems and its stability is proved. Validation and verification flight tests of L
N
lateral-directional guidance logic demonstrate superior tracking performance adaptability of this novel method compared to other methods such as
L
1
or
L
2
+
. The L
N
longitudinal guidance is newly developed in this paper and shows excellent altitude tracking capabilities and similarly scalable. Statistical analysis of multiple flight tests involving varying environmental states with three unique aircraft and different advanced flight controllers are shown to prove the capabilities, robustness, and consistency of L
N
guidance.
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper presents the flight test verification and validation of a novel multi-reference longitudinal and lateral -directional guidance logic across multiple autonomous aircraft with distinctly ...different dynamics. L.sub.N guidance logic takes advantage of tracking a span of multiple references across the desired track, similar to an insect's compound eyes, allowing for a much higher temporal resolution and more predictive and anticipatory guidance logic. The stability of L.sub.N guidance algorithms is investigated using global Lyapunov stability theorems and its stability is proved. Validation and verification flight tests of L.sub.N lateral-directional guidance logic demonstrate superior tracking performance adaptability of this novel method compared to other methods such as L.sub.1 or L.sub.2.sup.+. The L.sub.N longitudinal guidance is newly developed in this paper and shows excellent altitude tracking capabilities and similarly scalable. Statistical analysis of multiple flight tests involving varying environmental states with three unique aircraft and different advanced flight controllers are shown to prove the capabilities, robustness, and consistency of L.sub.N guidance. Keywords UAS * Flight test * Autonomy * 3D guidance * Predictive and adaptive guidance * UAM * Lyapunov
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Background. The prognosis of recurrent metastatic cervical cancer is extremely poor. Platinum-based palliative chemotherapy constitutes the mainstay of treatment. Cure is extremely rare. ...Case. We present 3 cases of recurrent metastatic cervical cancer in which the patients remain disease-free many years after completing salvage chemotherapy and surgery. The patients remain with no evidence of disease at 6, 7, and 13 years, respectively, following recurrence. Conclusion. In rare cases, an unexpected complete clinical remission and long-term survival without evidence of disease may be achieved in patients with recurrent metastatic cervical cancer treated with multimodal therapy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Sleepiness, a common complaint of epilepsy patients, is frequently attributed to antiepileptic medications. To determine predictors of subjective sleepiness in epilepsy patients, we gave ...self-administered, validated surveys of sleepiness Epworth sleepiness scale (our major outcome measure) and sleep apnea sleep apnea scale of the sleep disorders questionnaire (SA/SDQ) to 158 epilepsy patients and 68 neurology patients without epilepsy (controls). An elevated Epworth score (>10) was more likely in epilepsy patients compared to controls after controlling for age and gender (p < 0.05). When Epworth scores were adjusted for SA/SDQ scores and restless legs symptoms (RLS), however, epilepsy patients showed only a nonsignificant trend toward elevated Epworth scores compared to controls (p = 0.08). SA/SDQ scores (p < 0.005) and RLS (p < 0.007) were significant predictors of elevated Epworth score in both epilepsy patients and controls. Among the epilepsy patients, the number or type of antiepileptic medication, seizure frequency, epilepsy syndrome (partial vs. generalized), and the presence of sleep-related seizures were not significant predictors (p > 0.10) of elevated Epworth score. Before attributing sleepiness in epilepsy patients to antiepileptic medications or uncontrolled seizures, clinicians should consider the possibility of a coexisting sleep disorder.
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