Potential of subdermal solar energy harvesting for medical device applications based on worldwide meteorological data.

SIGNIFICANCE Active implants require batteries as power supply. Their lifetime is limited and may require a second surgical intervention for replacement. Intracorporal energy harvesting techniques generate power within the body and supply the implant. Solar cells below the skin can be used to harvest energy from light. AIM To investigate the potential of subdermal solar energy harvesting. APPROACH We evaluated global radiation data for defined time slots and calculated the output power of a subdermal solar module based on skin and solar cell characteristics. We assumed solar exposure profiles based on daily habits for an implanted solar cell. The output power was calculated for skin types VI and I/II. RESULTS We show that the yearly mean power in most locations on Earth is sufficient to power modern cardiac pacemakers if 10 min midday solar irradiation is assumed. All skin types are suitable for solar harvesting. Moreover, we provide a software tool to predict patient-specific output power. CONCLUSIONS Subdermal solar energy harvesting is a viable alternative to primary batteries. The comparison to a human case study showed a good agreement of the results. The developed code is available open source to enable researchers to investigate further applications of subdermal solar harvesting

Determinants of career development in cardiology – results from a Swiss national survey

BACKGROUND: Despite the rising proportion of female medical students and specialised female doctors in Switzerland, the field of cardiology remains one of the most male-dominated. OBJECTIVES: The goal of this study was to identify determinants of and obstacles to career development for cardiologists with special regard to an academic and interventional career. METHODS: Under the direction of the Swiss working group Women in Cardiology (IG-WIC), an online survey was conducted among Swiss cardiologists and cardiologists in training. RESULTS: 140 participants (43.6% female, 56.4% male; median age 45.0) were included. Women were more often single (27.9% vs 10.1%, p = 0.013) and less likely to have children (52.5% vs 70.9%, p = 0.034). If they had children, they were more likely to provide childcare themselves (37.5% vs 10.7%, p = 0.006) or to have interrupted their work in favour of parenting (40.6% vs 8.9%, p <0.001). A majority of women indicated a negative impact of their gender on their career development (78.7%), and 36.3% reported sexual harassment at their workplace. Women felt less supported in their professional training, especially concerning research activities. As a hindrance for pursuit of a career in academic medicine, both sexes stated lack of compatibility of work and family (44.6%) and the competitive work environment (55.4%) being most important. Women also identified gender-specific disadvantages as one of the main reasons for not choosing an academic or interventional career. CONCLUSIONS: The overall satisfaction among Swiss cardiologists is high regarding training in health care and the working atmosphere. However, women and men plead for better compatibility of work and family and better structured training curricula. Several gender-specific aspects hindering women from advancing in cardiology training should be addressed

Pretransplant pulmonary hypertension and long-term allograft right ventricular function

Background: Graft right ventricular (RV) function is compromised directly posttransplant, especially in heart transplantation (HTx) recipients with pretransplant pulmonary hypertension (PH). Graft RV size and systolic function, and the effect of the recipient's pulmonary haemodynamics on the graft extracellular matrix are not well characterised in the patients long-term after HTx. Aim: Comparison of RV size and systolic function in HTx recipients' long-term posttransplant stratified by the presence of pretransplant PH. Methods: HTx survivors ≥2 years posttransplant were divided into group I without pretransplant PH (pulmonary vascular resistance, PVR ≪2.5Wood units, n=37) and group II with PH (PVR ≥2.5Wood units, n=16). RV size and systolic function were measured using cardiac magnetic resonance imaging (CMR). The collagen content was assessed in septal endomyocardial biopsies obtained at HTx and at study inclusion. Results: Mean posttransplant follow-up was 5.2±2.9 years (group I) and 4.9±2.2 years (group II) (p=0.70). PVR was 1.5±0.6 vs 4.1±1.7Wood units pretransplant (p≪0.001), and 1.2±0.5 vs 1.3±0.5Wood units at study inclusion (p=0.43). Allograft RV size and systolic function were similar in both groups (p always ≥0.07). Collagen content at transplantation and at follow-up were not different (p always ≥0.60). Conclusion: Posttransplant normalisation of pretransplant PH is associated with normal graft RV function long-term after HT

Women in cardiology: past, present and future

In 2018, the Swiss Society of Cardiology celebrated its70thyear. Is this also a celebration for the achievement ofwomen in cardiology? Yes and no

Training-related modulations of the autonomic nervous system in endurance athletes: is female gender cardioprotective?

The risk of sudden death is increased in athletes with a male predominance. Regular physical activity increases vagal tone, and may protect against exercise-induced ventricular arrhythmias. We investigated training-related modulations of the autonomic nervous system in female and male endurance athletes. Runners of a 10-mile race were invited. Of 873 applicants, 68 female and 70 male athletes were randomly selected and stratified according to their average weekly training hours in a low (≤4h) and high (>4h) volume training group. Analysis of heart rate variability was performed over 24h. Spectral components (high frequency [HF] and low frequency [LF] power in normalized units) were analyzed for hourly 5min segments and averaged for day- and nighttime. One hundred and fourteen athletes (50% female, mean age 42±7years) were included. No significant gender difference was observed for training volume and 10-mile race time. Over the 24-h period, female athletes exhibited a higher HF and lower LF power for each hourly time-point. Female gender and endurance training hours were independent predictors of a higher HF and lower LF power. In female athletes, higher training hours were associated with a higher HF and lower LF power during nighttime. In male athletes, the same was true during daytime. In conclusion, female and male athletes showed a different circadian pattern of the training-related increase in markers of vagal tone. For a comparable amount of training volume, female athletes maintained their higher markers of vagal tone, possibly indicating a superior protection against exercise-induced ventricular arrhythmia

Pulsed-field ablation for the treatment of left atrial reentry tachycardia.

BACKGROUND We describe our initial experience using a multipolar pulsed-field ablation catheter for the treatment of left atrial (LA) reentry tachycardia. METHODS We included all patients with LA reentry tachycardia treated with PFA at our institution between September 2021 and March 2022. The tachycardia mechanism was identified using 3D electro-anatomical mapping (3D-EAM). Subsequently, a roof line, anterior line, or mitral isthmus line was ablated as appropriate. Roof line ablation was always combined with LA posterior wall (LAPW) ablation. Positioning of the PFA catheter was guided by a 3D-EAM system and by fluoroscopy. Bidirectional block across lines was verified using standard criteria. Additional radiofrequency ablation (RFA) was used to achieve bidirectional block as necessary. RESULTS Among 22 patients (median age 70 (59-75) years; 9 females), we identified 27 LA reentry tachycardia: seven roof dependent macro-reentries, one posterior-wall micro-reentry, twelve peri-mitral macro-reentries, and seven anterior-wall micro-reentries. We ablated a total of 20 roof lines, 13 anterior lines, and 6 mitral isthmus lines. Additional RFA was necessary for two anterior lines (15%) and three mitral isthmus lines (50%). Bidirectional block was achieved across all roof lines, 92% of anterior lines, and 83% of mitral isthmus lines. We observed no acute procedural complications. CONCLUSION Ablation of a roof line and of the LAPW is feasible, effective, and safe using this multipolar PFA catheter. However, the catheter is less suited for ablation of the mitral isthmus and the anterior line. A focal pulsed-field ablation catheter may be more effective for ablation of these lines. This study shows the feasibility to ablate linear lesions with a multipolar pulsed-field ablation catheter. 27 left atrial reentry tachycardia were treated in 22 patients

Impact of a structured institutional lead management programme at a high volume centre for transvenous lead extractions in Switzerland

BACKGROUND: Transvenous lead extraction (TLE) is the recommended management strategy for a variety of cardiac implantable electronic device (CIED) infections, malfunctions and other conditions. Large registries have established the safety and efficacy of TLE per se but temporal outcome data after the introduction of an institutional lead management programme remain scarce. OBJECTIVE: To investigate the impact of a structured institutional lead management programme on TLE outcomes. METHODS: All patients who underwent TLE at our institution between January 2013 and December 2020 were included. We assessed procedural outcomes after TLE for two separate time periods: from January 2013 to December 2018 and January 2019 to December 2020 (after introduction of a structured institutional lead management programme). RESULTS: In 2013–2018, the median number of TLE procedures per year at our centre was 14 (range 10–19, total 84). In 2019/2020, the median number of interventions per year increased to 46 (range 41–51, total 92). Noninfectious indications for TLE became more frequent (p <0.001), and the proportion of TLEs due to infections decreased. Median lead dwell time was not different (4.3 years [2013–2018] vs 4.4 years [2019–2020], p = 0.43). Clinical success rates improved from 90% to 98% (p = 0.020) and complete procedural success increased from 85% to 95% (p = 0.027). There was a trend towards a lower number of TLE-associated complications (p = 0.07). CONCLUSION: A structured institutional lead management programme and increasing experience significantly improve TLE outcomes. TLE can be safely performed in high-volume centres, allowing for a more liberal extraction policy, including in the case of non-infectious TLE indications