Garcia-Seara J, et al. - In a retrospective study, researchers sought to determine if patients with a better response to cardiac resynchronization therapy (CRT) could be predicted by different subtypes of true left bundle branch block (LBBB) configuration. The Strauss and the Predict study criteria were used to define true LBBB and an improvement in one category of the NYHA functional class was defined as clinical response. Greater echocardiographic response and a lower incidence of HF hospitalization were observed in patients with true LBBB, either Strauss or Predict criteria, as compared to non-true LBBB when implanted with CRT.