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Background Epicardial ganglionated plexuses (GP) have an important role in the pathogenesis of atrial fibrillation (AF). The relationship between anatomical, histological and functional effects of GP is not well known. We previously described atrioventricular (AV) dissociating GP (AVD-GP) locations. In this study, we hypothesised that ectopy triggering GP (ET-GP) are upstream triggers of atrial ectopy/AF and have different anatomical distribution to AVD-GP. Objectives We mapped and characterised ET-GP to understand their neural mechanism in AF and anatomical distribution in the left atrium (LA). Methods 26 patients with paroxysmal AF were recruited. All were paced in the LA with an ablation catheter. High frequency stimulation (HFS) was synchronised to each paced stimulus for delivery within the local atrial refractory period. HFS responses were tagged onto CARTO™ 3D LA geometry. All geometries were transformed onto one reference LA shell. A probability distribution atlas of ET-GP was created. This identified high/low ET-GP probability regions. Results 2302 sites were tested with HFS, identifying 579 (25%) ET-GP. 464 ET-GP were characterised, where 74 (16%) triggered ≥30s AF/AT. Median 97 (IQR 55) sites were tested, identifying 19 (20%) ET-GP per patient. >30% of ET-GP were in the roof, mid-anterior wall, around all PV ostia except in the right inferior PV (RIPV) in the posterior wall. Conclusion ET-GP can be identified by endocardial stimulation and their anatomical distribution, in contrast to AVD-GP, would be more likely to be affected by wide antral circumferential ablation. This may contribute to AF ablation outcomes.

Twenty-one-hour melatonin plasma profiles were studied in 15 normal elderly volunteers from the community, and eight who had been in hospital for more than six weeks and who had not been exposed to strong natural lighting. The hospital group had significantly higher daytime plasma melatonin levels, an earlier nocturnal rise, and the timing of their secretory profiles was more variable. These results suggest that currently used artificial and supplementary natural lighting may not be sufficient to suppress melatonin secretion adequately during daylight hours nor act efficiently to entrain day/night secretion of melatonin in a physiological circadian manner. Raised melatonin levels by day and variable secretory profiles at night may account for certain mood and sleep disorders observed in institutionalized people.

Greater three-dimensional separation of LV-to-RV leads is associated with improved response to CRT. A prospective multicenter trial is needed to assess lead separation as a predictor for response.

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Background A subset of patients experience psychological distress following insertion of an implantable cardioverter-defibrillator (ICD) and ICD support groups are recommended, however access to these groups is limited. This study aimed: to gauge a better understanding of patients’ key ICD-related concerns; to determine patient interest in a support group and topics deemed helpful to address in a support group; and to examine factors which affect patient inclination to attend. Methods One hundred and thirty nine patients completed the ICD Patient Concerns Questionnaire – Brief (ICDC-B) and a semi-structured survey. Non-parametric tests were used to examine associations and differences in the quantitative data. Qualitative data were analysed using thematic analysis. Results 42% of respondents said they would attend a support group and inclination to attend was associated with higher ICD concerns and a shorter time since implant. Topics considered important to address in a group were information about heart conditions and devices, the impact of an ICD on daily life and coping with fear of shocks. Conclusion We concluded that there is interest in further support amongst many patients and that ICD support groups may be delivered efficiently by targeting patients who have higher levels of ICD concerns and within the first few years after implant.

Left ventricular pseudoaneurysm is a rare complication that can result from mitral valve replacement. Proper follow-up imaging can help to detect this potentially fatal complication and identify areas of concern. Infective endocarditis following mitral valve replacement can occur and further lead to the development of a pseudoaneurysm. We describe a case of left ventricular aneurysm in the setting of infective endocarditis following mitral valve replacement and present radiologic images from various modalities detailing the major findings.