Non-invasive evaluation of new-onset atrial fibrillation after cardiac surgery: a protocol for the BigMap study.

AIMS: New-onset atrial fibrillation (NOAF) is the most common complication after cardiac surgery, occurring in 25-50% of patients. It is associated with post-operative stroke, increased mortality, prolonged hospital length of stay, and higher treatment costs. Previous small observational studies have identified the left atrium as a source of the electrical rotors and foci maintaining NOAF, but confirmation by a large prospective clinical study is still missing. The aim of the proposed study is to investigate whether the source of NOAF lies in the left atrium. The correct identification of NOAF-maintaining structures in cardiac surgical patients might offer potential therapeutic targets for prophylactic perioperative ablation strategies. METHODS AND RESULTS: This is a prospective single-centre observational study of patients developing NOAF after cardiac surgery. The primary outcome is the description of NOAF-maintaining structures within the atria. Key secondary outcomes include overall mortality, intensive care unit length of stay, hospital-ventilator-free days, and proportion of persistent NOAF. In NOAF patients, the non-invasive electrophysiological mapping will be conducted using a 252-electrode electrocardiogram vest. After mapping, a low-dose computed tomography scan of the chest will be performed to integrate the electrophysiological mapping results into a 3D picture of the heart. The study will include approximately 570 patients, of whom 30% (n = 170) are expected to develop NOAF. Sample size calculation revealed that 157 NOAF patients are necessary to assess the primary outcome. Patients will be tracked for a total of 5 years. CONCLUSIONS: This is the largest prospective study to date describing the electrophysiological mechanisms of NOAF using non-invasive mapping.

Gender-focused training improves leadership of female medical students: A randomised trial.

OBJECTIVES: Recent research suggests that the gender of health care providers may affect their medical performance. This trial investigated (1) the effects of the gender composition of resuscitation teams on leadership behaviour of first responders and (2) the effects of a brief gender-specific instruction on leadership behaviour of female first responders. METHODS: This prospective randomised single-blinded trial, carried out between 2008 and 2016, included 364 fourth-year medical students of two Swiss universities. One hundred and eighty-two teams of two students each were confronted with a simulated cardiac arrest, occurring in the presence of a first responder while a second responder is summoned to help. The effect of gender composition was assessed by comparing all possible gender-combinations of first and second responders. The gender-specific instruction focused on the importance of leadership, gender differences in self-esteem and leadership, acknowledgement of unease while leading, professional role, and mission statement to lead was delivered orally for 10 min by a staff physician and tested by randomising female first responders to the intervention group or the control group. The primary outcome, based on ratings of video-recorded performance, was the first responders' percentage contribution to their teams' leadership statements and critical treatment decision making. RESULTS: Female first responders contributed significantly less to leadership statements (53% vs. 76%; P = 0.001) and critical decisions (57% vs. 76%; P = 0.018) than male first responders. For critical treatment decisions, this effect was more pronounced (P = 0.007) when the second responder was male. The gender-specific intervention significantly increased female first responder's contribution to leadership statements (P = 0.024) and critical treatment decisions (P = 0.034). CONCLUSIONS: Female first responders contributed less to their rescue teams' leadership and critical decision making than their male colleagues. A brief gender-specific leadership instruction was effective in improving female medical students' leadership behaviours.

Influence of Gender on the Performance of Cardiopulmonary Rescue Teams: A Randomized, Prospective Simulator Study.

OBJECTIVES: Little is known about the influence of gender on resuscitation performance which may improve future education in resuscitation. The aim of this study was to compare female and male rescuers in regard to cardiopulmonary resuscitation and leadership performance. DESIGN: Prospective, randomized simulator study. SETTING: High-fidelity patient simulator center of the medical ICU, University Hospitals Basel (Switzerland). SUBJECTS: Two hundred sixteen volunteer medical students (108 females and 108 males) of two Swiss universities in teams of three. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed data on the group and the individual level separately. The primary outcome on the group level was the hands-on time within the first 180 seconds after the onset of the cardiac arrest. Compared with male-only teams, female-only teams showed less hands-on time (mean ± SD) (87 ± 41 vs 109 ± 33 s; p = 0.037) and a longer delay before the start of chest compressions (109 ± 77 vs 70 ± 56 s; p = 0.038). Additionally, female-only teams showed a lower leadership performance in different domains and fewer unsolicited cardiopulmonary resuscitation measures compared with male-only teams. On the individual level, which was assessed in mixed teams only, female gender was associated with a lower number of secure leadership statements (3 ± 2 vs 5 ± 3; p = 0.027). Results were confirmed in regression analysis adjusted for team composition. CONCLUSIONS: We found important gender differences, with female rescuers showing inferior cardiopulmonary resuscitation performance, which can partially be explained by fewer unsolicited cardiopulmonary resuscitation measures and inferior female leadership. Future education of rescuers should take gender differences into account.