Abstract 18654: Expert Adjudication of Device Electrograms: Is an Atrial Channel More Important than Gray Hair?

Abstract

Background: The diagnosis of a tachycardia from ICD recordings ultimately depends upon analysis of captured electrograms (EGMs). While atrial EGM may improve tachycardia discrimination, the degree of benefit has not been evaluated in medical professionals with different level of expertise. Methods: Expert-adjudicated supraventricular tachycardia (SVT) and ventricular tachycardia (VT) EGMs from the RATE Registry were given to EP Specialists (EPS), EP Fellows (EPF), and Nurse Practitioners or Physician Assistants (NPPA). Each participant diagnosed 112 EGMs (61 VTs, 51 SVTs) as SVT, VT, or Uncertain in two stages. First, participants made diagnosis based on ventricular EGM (VEGM) alone (Atrial Channel covered). Then the EGMs were re-randomized with atrial EGM exposed and diagnosis was made again. The accuracy of diagnosis by EPS, EPF, and NPPA in the use of VEGM alone vs dual-chamber EGM was assessed. Results: Fifteen participants (5 in each group) completed diagnosis. All 3 groups significantly improved diagnosis accuracy (>20% for VTs, >15% for SVTs, all p values < 0.02) when dual-chamber EGM was provided. EPS diagnosed VTs more accurately than NPPA (VEGM: 73.1±7.6% vs 56.1±14.1%, p = 0.03; dual-chamber EGM: 98.0±2.7% vs 80.3±7.4%, p = 0.001). EPF diagnosed VTs better than NPPA but worse than EPS (not statistically significant). There was no significant intergroup difference in SVT diagnosis. Conclusion: These results suggest that atrial EGMs help rhythm discrimination at all levels of expertise. However, experience seems to improve diagnosis accuracy with and w/o atrial EGM.