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Implantation of Pacemakers and ICDs
Published in Andrea Natale, Oussama M. Wazni, Kalyanam Shivkumar, Francis E. Marchlinski, Handbook of Cardiac Electrophysiology, 2020
Kushwin Rajamani, Michael P. Brunner, Oussama M. Wazni, Bruce L. Wilkoff
When a lead is screwed into atrial or ventricular tissue, there is an initial current of injury. Over the subsequent 6–8 weeks, the lead matures as the injured myocardium surrounding the lead fibroses. This can cause an increase in the capture threshold from the time of implantation to time of lead maturation at 6–8 weeks. Thus, at the time of device implantation, pacing output is set to a high output (usually 5 V). Thresholds checked at 6–8 weeks post-implantation are usually stable and pacing outputs are then set to 1.7 to 2 times the capture thresholds.
The electrocardiogram in ischaemic heart disease
Published in John Edward Boland, David W. M. Muller, Interventional Cardiology and Cardiac Catheterisation, 2019
Geoffrey S. Oldfield, Dennis L. Kuchar
Necrotic or scar tissue is electrically inactive so that an electrical “window” appears when an electrode is placed over the infarct. In Figure 19.7, the interventricular septum and right ventricular free wall are recorded from the electrode facing the left ventricular free wall. When cardiac tissue is ischaemic or injured, it becomes electrically negative, whereas the adjacent normal tissue remains positively charged. As a consequence, a negative current of injury is recorded from the injured surface by an electrode facing it (as in Figure 19.7), and a continuous positive current is recorded by an electrode facing the normal tissue adjacent to the injured tissue (as in Figure 19.8a).
Pericardial disease in the elderly
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Traditionally, ECG changes associated with pericarditis have been classified in four stages (reported in no more than 50%–60% of cases with ECG changes), though not all the stages are observed in all pericarditis patients due to that treatment can accelerate or alter ECG progression and also the duration of the ECG changes in pericarditis depends on its cause and the extent of any associated myocardial damage (12). However, the pericardium is electrically silent in the absence of myocardial involvement (at least subepicardial), and this means that ECG changes can be missing in pure pericarditis (e.g., uremic pericarditis) and are more common with concomitant myocarditis (e.g., myopericarditis) (1–4,13). In stage 1, diffuse concave ST-segment elevation (secondary to epicardial inflammation) and PR-segment depression are seen within the first hours to days, with corresponding ST-segment depression in aVR and usually V1. There can also be PR-segment elevation in aVR suggestive of an atrial current of injury. The TP segment should be considered as the isoelectric segment in defining the ST-segment deviation. ST-segment normalization is noted in stage 2 followed by T-wave flattening and inversion in stage 3. Stage 4 is characterized by the return of the ECG to either prepericarditis state or indefinitely persistent T-wave inversions (common in cases destined to constrict) (12) (Figure 28.3).
Awareness of deficit following traumatic brain injury: A systematic review of current methods of assessment
Published in Neuropsychological Rehabilitation, 2021
Laura Brown, Jessica Fish, Daniel C. Mograbi, Giulia Bellesi, Keyoumars Ashkan, Robin Morris
Additional variation across instruments was noted regarding the timings of assessment. The majority of instruments focused on current post-injury functioning. However, for two of the commonly used patient-proxy measures in this review, (the AQ and the FrSBe) respondents were asked to rate how well they are currently functioning compared to before the injury (i.e., better, the same or worse; AQ or in the case of the FrSBE, rate both pre- and post-injury functioning). Both allow an index of change to be assessed and suggest that this change index is valued following TBI. There is debate regarding whether the measures of awareness that involve pre–post-ratings may be more complex than those focused solely on current functioning (Niemeier et al., 2014), which if true may again make cross study comparison challenging and as such may warrant further attention.
Urban versus rural setting as a predictor of injury type and severity among pediatric pedestrians: using a database derived from state-wide crash data and hospital discharge data in Illinois
Published in International Journal of Injury Control and Safety Promotion, 2020
Colleen Fant, Joy Koopmans, Norma-Jean E. Simon, Doug Lorenz, Karen Rychlik, Karen Sheehan
On a state-wide level, injury severity and specific pediatric pedestrian injury were related to the population density of the crash site. Specifically, patients were noted as having more severe injuries at the time of the crash in suburban and rural settings. While all injuries except ‘Sprains/Strains’ were more likely as population density got lower, this was especially true for ‘Internal Organ’ and ‘Traumatic Brian’ injuries. This may reflect traffic patterns, current pedestrian injury prevention strategies in these locations, reporting bias, or other unrecognized phenomenon that will need to be addressed in future studies. Interestingly, sprain and strain injuries were not related to population density of crash location, though this may be due to their ubiquitous nature during crashes.
The nature of occupational gaps and relationship with mood, psychosocial functioning and self-discrepancy after severe traumatic brain injury
Published in Disability and Rehabilitation, 2020
Elizabeth Jane Beadle, Tamara Ownsworth, Jennifer Fleming, David H. K. Shum
Given that participation in valued activities and social roles is typically reduced after TBI, it is not surprising that many individuals report changes in self-concept. Individuals with TBI often make unfavourable comparisons between their pre-injury and post-injury selves, which is commonly referred to as “negative self-discrepancy” [22]. Using the Head Injury Semantic Differential (HISD) Scale III [23], Reddy et al. [24] found that participants with TBI rated their current (post-injury) selves as less interested, independent, and active than their past (pre-injury) selves. A systematic review identified that negative self-discrepancy after TBI was typically associated with greater anxiety and depression [25]. Although greater occupational gaps are found to be related to poorer mental health (i.e., lower life satisfaction and depression) [18], the relationship between occupational re-engagement, mood and self-discrepancy has yet to be investigated. Due to the subjective nature of desired occupational engagement (i.e., activities the person wants to participate in), it is also unclear whether occupational gaps correspond with individuals’ psychosocial functioning, or their levels of independence, relationship functioning and work and leisure skills as rated by relatives.