Septal flash predicts cardiac resynchronization therapy response in patients with permanent atrial fibrillation

Patients with heart failure (HF) as well as atrial fibrillation (AF) have suboptimal response to cardiac resynchronization therapy (CRT). Identification of mechanical abnormalities, amenable to correction with CRT, might improve the selection of candidates and CRT efficiency. We evaluated whether abnormal septal motion, assessed by the presence of septal flash (SF) is related to CRT response in patients with AF.

Ninety-four CRT patients with AF were included. Echocardiography was performed in all subjects at baseline and at 12-month follow-up. Abnormal septal motion was defined by the presence of SF (early septal inward/outward motion within the isovolumic contraction period/QRS duration). Response to CRT was defined as a reduction (>15%) of the end-systolic volume of the left ventricle (LV). Univariate and multivariate analyses were performed to identify the predictors of CRT response. The mean age was 69 ± 8 years, 79% were males, and 59% of patients responded to CRT. Cardiovascular death was 14.4% and all-cause mortality was 16.5% during follow-up. Patients with SF at baseline that was acutely corrected by CRT were significantly more likely to respond than patients without SF. Baseline SF was an independent predictor of CRT response (OR 5.24; 95% CI 1.95-14.11).

Abnormal septal motion, assessed by the presence of SF, is a mechanism amenable to CRT correction. Its correction is associated with a higher likelihood of CRT response in HF patients with long-standing AF. This could improve the selection of candidates to CRT in a subgroup with particularly poor response and long-term prognosis.