In Kaplan‒Meier analysis, patients with NSIVCD and LBBB showed higher event rates than patients without IVCD, while RBBB patients did not. Of 548 DCM patients, there were 398 males (72.6%), and the average age was 46 ± 15 years, ranging from 18 to 76 years.

The associations between different patterns of IVCD and the outcomes of DCM were analysed by Kaplan‒Meier analysis and Cox proportional hazards regression analysis. After a median follow-up of 58 months (interquartile range: 47–65), 123 patients reached the composite endpoints, which included cardiovascular death, heart transplantation, and malignant arrhythmias. The cohort was divided into four groups: 87 with LBBB, 27 with RBBB, 61 with NSIVCD, and 373 without intraventricular conduction delay (IVCD). MethodsĪ total of 548 DCM patients who underwent cardiovascular magnetic resonance imaging (CMR) from January 2016 to December 2017 were consecutively enrolled. We aimed to evaluate the prognosis of DCM with NSIVCD. However, prognostic data on nonspecific intraventricular conduction delay (NSIVCD) are still limited and conflicting. Atypical left bundle branch morphology defined as QS or rS in lead V1, broad R waves in lead I, and aVL but with QS or rS in V5-V6 is associated with favorable echocardiographic response to CRT and displays similar survival rates to typical LBBB patients.Ītypical left bundle branch block Cardiac resynchronization therapy Heart failure Left bundle branch block.Left bundle branch block (LBBB) has been confirmed to be independently associated with adverse outcomes in dilated cardiomyopathy (DCM). This subgroup of IVCD should be considered for CRT. Patients with ALBBB may have a favorable echocardiographic response to CRT and display similar survival rates to typical LBBB. Cumulative 2-year survival was 88% in ALBBB, 86% in TLBBB, and 76% in OIVCD (p value = 0.011). A multivariable model showed a lower likelihood of echocardiographic response in OIVCD and a similar likelihood in ALBBBB compared to TLBBB. 75% and 72%, respectively, p = 0.01 for both comparisons). Rates of echocardiographic response were lower among those with OIVCD compared to those with LBBB and ALBBB (50% vs. Endpoints were 2 years mortality and echocardiographic response, defined as a decrease of ≥ 10% in indexed LVESV or an increase of ≥ 5% in left ventricular ejection fraction at 1 year of follow-up.īaseline clinical characteristics were similar among all the three groups.

ECGs were classified into the following three groups: (a) typical LBBB (TLBBB) according to accepted guidelines (n = 67) (b) IVCD with LBBB pattern criteria in V1, 1, and aVL but with QS or rS in V5-V6 which we defined as atypical LBBB (ALBBB) (n = 74) and (c) all other IVCD (OIVCD) patterns (n = 98). However, IVCD pattern is heterogeneous, and it is possible that QRS patterns may also respond to CRT.Ĭonsecutive baseline ECGs of 239 patients implanted between 20 with CRT were analyzed. Response to cardiac resynchronization therapy (CRT) is well-established in patients with typical left bundle branch block (LBBB) but modest or even negative in those with intraventricular conduction delay (IVCD).

Lbbb vs ivcd