Increasing Diversity in Cardiology: A Fellowship Director's Perspective.

Background Underrepresented-minorities (URM) remain few in number amongst practicing cardiologists and across cardiology fellowship training programs in the U.S. Increased diversity is needed across the entire field and is particularly necessary within graduate medical education cardiology fellowship training programs. Objectives This cross-sectional study was performed to identify which strategies were supported and implemented by cardiology fellowship program directors (PDs) to increase URM representation, to determine which entities hold the responsibility to increase diversity according to program directors, and to quantify URM representation in cardiology fellowship programs. Methods A 15-item survey was submitted to all American College of Graduate Medical Education (ACGME) accredited cardiology fellowship programs via electronic mail. Results Of 250 cardiology fellowship programs, 71 responses were received (28.4%). The number of URM faculty varied from 0-1 to more than six, and URM faculty held leadership roles in most programs (62.0%). A total of 16 respondents (22.5%) were URM program directors. Most respondents agreed that diversity was important to their training program (85.9%). The majority endorsed direct recruitment of URM applicants (60.6%), opportunities for applicants to connect with (54.9%) or be recruited by URM fellows (54.9%), holistic application review (67.6%), promoting mentorship by URM faculty (69.0%), URM faculty involvement in applicant interviewing (54.9%), and increased recruitment of URM faculty members (73.2%). Program directors allocated major responsibility to increase diversity to fellowship programs (71.8%), residency programs (63.3%), and medical schools (53.5%). Conclusions This study found that most cardiology programs have URM faculty in leadership roles, and nearly a quarter of the surveyed program directors were URMs. Cardiology program directors endorsed and employed numerous strategies to increase diversity and URM representation in fellowship programs. Additionally, program directors held fellowship training programs most responsible for increasing URM representation in the field of cardiology.

The impact of pharmacologic sympathetic and parasympathetic blockade on atrial electrogram characteristics in patients with atrial fibrillation.

BACKGROUND: Ablation of atrial autonomic inputs exerts antifibrillatory effects. However, because ablation destroys both myocardium and nerve cells, the effect of autonomic withdrawal alone remains unclear. We therefore examined the effects of pharmacologic autonomic blockade (PAB) on frequency and fractionation in patients with atrial fibrillation (AF). METHODS: Esmolol and atropine were administered and electrograms were recorded simultaneously from both atria and the coronary sinus. In 17 patients, AF was recorded for 5 minutes and dominant frequency (DF) and continuous activity (CA) were compared before and during PAB. RESULTS: Examination of the pooled data (537 sites, 17 patients) revealed a statistically significant decrease in mean DF (5.61­5.43Hz, P < 0.001) during PAB. Site-by-site analysis showed that 67% of sites slowed (0.45 ± 0.59 Hz), whereas 32% accelerated (0.49 ± 0.59Hz). Fractionation was reduced: median CA decreased from 31% to 26% (P < 0.001). In patient-by-patient analysis, mean DF/median CA decreased in 13 of 17 patients and increased in four. The spatial heterogeneity of DF decreased in nine of 17 patients (spatial coefficient of variation of DF at "nondriver sites" decreased by a mean of 2%). CONCLUSION: PAB decreases DF and CA in the majority of sites. Given the complexity of interactions between atrial cells during AF, the effects of PAB on DF and fractionation are more heterogeneous than the effects of PAB on isolated cells.

The temporal variability of dominant frequency and complex fractionated atrial electrograms constrains the validity of sequential mapping in human atrial fibrillation.

BACKGROUND: It has been proposed that sequential mapping of dominant frequency (DF) and complex fractionated atrial electrograms (CFAE) can identify target sites for ablation of atrial fibrillation (AF). These mapping strategies are valid only if DF and CFAE are temporally stable on the timescale of the mapping procedure. We postulate that DF and CFAE are temporally variable; consequently, sequential mapping can be misleading. OBJECTIVE: To make prolonged spatially stable multielectrode recordings to assess the temporal stability of DF and CFAE. METHODS: We recorded electrical activity for 5 minutes with the use of a 64-electrode basket catheter placed in the left atrium of 18 patients presenting for AF ablation. DF and CFAE were determined off-line, and their temporal variability was quantified. Maps created from simultaneous versus sequentially acquired data were compared. RESULTS: DF was temporally variable: the average temporal coefficient of variation was 22.7% +/- 5.4%. DF sites were transient, meeting criteria for only 22.1 seconds out of 5 minutes. Similarly, CFAEs were transient (average duration of CFAE 8.8 +/- 11.3 seconds). DF and CFAE sequential maps failed to identify 93.0% +/- 12.4% and 35.9% +/- 14.9% of DF and CFAE sites, respectively. CONCLUSION: Because of temporal variability, sequential DF and CFAE maps do not accurately reflect the spatial distribution of excitation frequency during any given sampling interval. The spatial distribution of DF and CFAE sites on maps created with sequential point acquisition depends upon the time at which each site is sampled.

Pulmonary vein encircling ablation alters the atrial electrophysiologic response to autonomic stimulation.

OBJECTIVE: Pulmonary vein encircling ablation is often effective in the treatment of atrial fibrillation (AF). The success of the procedure does not depend upon creation of continuous lines of block. Thus mechanisms by which pulmonary vein encircling can cure AF remain unclear. Stimulation of cardiac autonomic ganglia alters atrial refractoriness and potentiates AF. We hypothesized that pulmonary vein encircling alters atrial autonomic function and that these alterations account in part for prevention of AF recurrences following ablation. METHODS: Atrial effective refractory periods (ERP) and AF inducibility were quantified in ten dogs before and during central autonomic nerve stimulation. Pulmonary vein encircling ablation was then performed and electrophysiologic testing repeated. In two dogs subjected to sham procedures measurements were repeated without performance of ablation. Hearts were examined histologically. RESULTS: Autonomic nerve stimulation led to decreased atrial refractoriness and increased AF inducibility and duration. Each of these effects were attenuated following pulmonary vein encircling (e.g., mean ERP decreased before (-23.7 +/- 1.8, p < 0.001) but not after ablation (-2.3 +/- 1.9, p = 0.25); AF inducibility increased by 26% before vs. 5% after ablation). No attenuation was seen in the sham operated animals. Histologic analysis following pulmonary vein encircling demonstrated destruction of some but not all autonomic ganglia. CONCLUSION: Autonomic stimulation shortens atrial refractory periods and potentiates AF. Pulmonary vein encircling ablation partially destroys atrial autonomic inputs, attenuates the refractory period shortening effect of autonomic stimulation and decreases AF inducibility. Destruction of autonomic ganglia may contribute to the anti-fibrillatory effects of pulmonary vein encircling and warrants further investigation.