Electrocardiographic characterization of myocardial scar in presence of conduction abnormality

Presence, extent and localization of myocardial scar constitute prognostic clinical information that can influence therapeutical decisions. Cardiovascular magnetic resonance imaging with late gadolinium enhancement (CMR-LGE) is the preferred method to image myocardial scar in vivo but is resource intensive and has contraindications. The 12-lead electrocardiogram (ECG) is less accurate but inexpensive and widely available. Adaptations of the Selvester QRS score, an ECG analysis system for scar characterization, were developed in 2009 for use in presence of conduction abnormalities such as left bundle branch block (LBBB). Prior to the work described in this thesis, these newly developed Selvester QRS score adaptations had only been preliminarily validated against CMR-LGE. The overall aim of the thesis was to evaluate the diagnostic performance and clinical utility in predicting response to cardiac resynchronization therapy (CRT) of the 2009 Selvester QRS score for use in the presence of conduction abnormality, and to revise the LBBB version (2009 LBSS) based on empirical CMR-LGE data. We found that the ECG criteria comprising the 2009 LBSS had modest ability to localize CMR-LGE verified myocardial scar within the left ventricle (LV) (study I). Next, we evaluated the ability of the Selvester QRS score adaptations for use in LBBB, right bundle branch block (RBBB), left anterior fascicular block (LAFB) and combined RBBB+LAFB to identify and quantify myocardial scar as verified by CMR-LGE. The results revealed a tendency of the ECG method to overestimate scar burden and presence compared to CMR- LGE (study II). We then investigated the individual specificity of the 46 QRS morphology criteria that comprise the 2009 LBSS and found that certain criteria hade prohibitively low specificity, likely causing the overestimation of myocardial scar size and presence found previously (study III). We further evaluated the ability of all Selvester QRS score adaptations to predict response to CRT in a randomized cohort. Scar burden estimated by QRS scoring did predict clinical outcome in both study arms but could not distinguish who benefitted from CRT in terms of reduced risk of heart failure event or death (study IV). Finally, we assembled a large training dataset of 325 patients in which we performed careful continuous measurements on digital ECGs. We subsequently compared ECG measurements to myocardial scar quantified by CMR-LGE. We achieved an improved method of ECG scar detection in LBBB compared to the 2009 LBSS that remains to be tested in an independent population. The Selvester QRS score adaptations for presence of conduction abnormalities tends to overestimate scar and has limited correlation with CMR-LGE verified scar presence and extent. The 12-lead ECG likely contains insufficient information for accurate quantification of myocardial scar in LBBB. However, it may still be possible to distinguish between scar presence and absence using the 12-lead ECG in presence of LBBB

The Role of Amygdala Subregions in the Neurobiology of Social Anxiety Disorder

Social anxiety is characterised by fear and/or avoidance of social situations in which an individual may be scrutinised by others. Social anxiety is thought to exist as a spectrum, with individuals on the high-end experiencing frequent and severe anxiety in the context of social situations. When severe social anxiety is accompanied by distress and functional impairment, a diagnosis of social anxiety disorder (SAD) can be made. SAD is a prevalent and debilitating disorder that can be unremitting and pervasive in the absence of intervention. Current psychotherapeutic and pharmacotherapeutic treatments for SAD demonstrate limited efficacy in remitting symptoms. Therefore, it is important to achieve a better understanding of the neurobiological mechanisms implicated in this disorder and identify potential neural treatment targets to develop more efficacious treatments. This thesis aimed to further investigate the neurobiological mechanisms implicated in SAD (vs. controls) and the associations between neural functioning and social anxiety as a dimensional symptom, with a focus on the amygdala and four of its subregions (the amygdalostriatal, basolateral, centromedial, and superficial subregions). This was due to previous findings in the neuroimaging literature in SAD having consistently implicated the amygdala, albeit with mixed findings of both increased and decreased functioning in those with SAD compared to controls. In the literature to date, however, most studies had examined the amygdala as a singular homogenous region due to methodological limitations in being able to examine the functionally and structurally distinct subnuclei that make up this region. By examining the amygdala subregions through the use of multiband functional magnetic resonance imaging (fMRI), this thesis additionally sought to determine whether the mixed findings in the literature to date may be a result of amygdala subregion-specific activity and connectivity patterns. This was achieved through three research studies. Firstly, Study 1 involved a comprehensive systematic review that summarised the literature on resting-state neuroimaging in SAD with a focus on fMRI studies and findings specific to the amygdala and its subregions (Chapter 3). This was followed by two empirical studies which investigated the role of the amygdala and its subregions during resting-state (Study 2) and emotion processing (Study 3) fMRI paradigms (Chapters 5 and 6, respectively). Findings from the systematic review (Study 1) highlighted the mixed findings in the resting-state neuroimaging literature in SAD to date, along with methodological limitations relating to neuroimaging acquisition and analysis. The empirical studies sought to address these limitations and demonstrated differing amygdala subregion activity and connectivity patterns at rest and during emotion processing. In the resting-state fMRI study (Study 2), there were no statistically significant differences in functional connectivity of the amygdala and its subregions in those with SAD compared to controls. However, social anxiety severity was found to be positively associated with connectivity between the superficial subregion and the supramarginal gyrus. The superficial subregion, along with the basolateral and centromedial subregions, were also implicated in the task-based emotion processing fMRI study (Study 3). In response to happy, angry, and fearful faces, those with SAD (vs. controls) had hyperactivation of the superficial subregion, hypoconnectivity between the superficial subregion and the precuneus, and hyperconnectivity between the basolateral subregion and broader brain regions (i.e., the pre/postcentral gyrus and the supramarginal gyrus). Additionally, social anxiety severity was positively associated with superficial and centromedial activation. Overall, the findings from this thesis provide novel information to the current understanding of the neurobiology of SAD by demonstrating amygdala subregion-specific alterations. This has important implications for research, theory, and clinical practice that are detailed in the thesis discussion (Chapter 7). Briefly, in terms of research, findings from the thesis provide support for the continuing investigation of SAD using both dimensional and categorical approaches. This was evident by the findings from the two empirical papers which demonstrated positive associations between subregional activity and connectivity patterns and social anxiety severity. With regards to theory, differences in neural patterns that were observed at rest (Study 2) and during emotion processing (Study 3) provide support for distinct neurobiological models to be constructed based on whether those with SAD are in the absence or presence of social stimuli. This is in contrast to the most recently proposed neurobiological model of SAD which was informed by a combination of resting-state and task-based fMRI data. Finally, with regards to clinical practice, the findings from this thesis provide preliminary evidence of the superficial, basolateral, and centromedial subregions of the amygdala as being potential treatment targets that can be used to inform the development of more efficacious treatments for SAD

The Application of Computer Techniques to ECG Interpretation

This book presents some of the latest available information on automated ECG analysis written by many of the leading researchers in the field. It contains a historical introduction, an outline of the latest international standards for signal processing and communications and then an exciting variety of studies on electrophysiological modelling, ECG Imaging, artificial intelligence applied to resting and ambulatory ECGs, body surface mapping, big data in ECG based prediction, enhanced reliability of patient monitoring, and atrial abnormalities on the ECG. It provides an extremely valuable contribution to the field

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias

XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016)

En la presente edición, más de 150 trabajos de alto nivel científico van a ser presentados en 18 sesiones paralelas y 3 sesiones de póster, que se centrarán en áreas relevantes de la Ingeniería Biomédica. Entre las sesiones paralelas se pueden destacar la sesión plenaria Premio José María Ferrero Corral y la sesión de Competición de alumnos de Grado en Ingeniería Biomédica, con la participación de 16 alumnos de los Grados en Ingeniería Biomédica a nivel nacional. El programa científico se complementa con dos ponencias invitadas de científicos reconocidos internacionalmente, dos mesas redondas con una importante participación de sociedades científicas médicas y de profesionales de la industria de tecnología médica, y dos actos sociales que permitirán a los participantes acercarse a la historia y cultura valenciana. Por primera vez, en colaboración con FENIN, seJane Campos, R. (2017). XXIV congreso anual de la sociedad española de ingeniería biomédica (CASEIB2016). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/79277EDITORIA

Epilepsy

With the vision of including authors from different parts of the world, different educational backgrounds, and offering open-access to their published work, InTech proudly presents the latest edited book in epilepsy research, Epilepsy: Histological, electroencephalographic, and psychological aspects. Here are twelve interesting and inspiring chapters dealing with basic molecular and cellular mechanisms underlying epileptic seizures, electroencephalographic findings, and neuropsychological, psychological, and psychiatric aspects of epileptic seizures, but non-epileptic as well