Sandhu A, et al. – Researchers determined whether the use of cardiac resynchronization therapy defibrillator (CRT-D) changed with the American College of Cardiology/American Heart Association/Heart Rhythm Society guideline update in 2012. The study sample consisted of 88,923 patients undergoing initial CRT-D implantation, of which 83.1% were guideline concordant. Overall, they noted an increased rate of guideline-concordant CRT-D implantation during the study, and the major fraction of guideline-discordant implants were clustered at a minority of hospitals. Conduction abnormalities correlated with guideline-discordant implants, which suggested further opportunity for dissemination and understanding of guideline updates.