Discordant vs. concordant left bundle branch block: A potential clinical significance.

Aim: LBBB in heart failure patients has prognostic significance. Subtypes of LBBB (concordant and discordant) have not been considered when considering management. The aim of this study is to explore the clinical difference between the two subtypes.

Methods: 216 patients with LBBB were included and categorized into concordant (LBBBC) and discordant (LBBBD) groups.

Results: Of the 216 patients (age 69.13±11.7; 56% male 44% female), 133 (61.5%) were LBBBD and 83 (38.5%) were LBBBC. LBBBD patients presented with lower LVEF (mean 36% vs 51%; P<0.001), wider QRS (mean 160 ms vs 151 ms; P<0.001), larger LA (mean 45 cm(2) vs 40 cm(2); P<0.001), moderate to severe mitral and tricuspid regurgitation (17% vs 3%; P<0.05, 10% vs 1%; P<0.05 respectively), CKD (41% vs 18%; P<0.001), COPD (4.6% vs 0%; P<0.01), CAD (67% vs 36%; P<0.001), and CABG (39% vs 16%; P<0.001).

Conclusion: LBBBD is significantly associated with worse cardiac function and clinical characteristics.