Predictive Value of Septal Flash for Reduction of Left Ventricular Systolic Function as Reflected by Global Longitudinal Strain Using Echocardiography in Patients With Isolated Complete Left Bundle-Branch Block.

BACKGROUND: Septal leftward motion followed by a counter motion during early systole is known as septal flash (SF) in patients with isolated complete left bundle-branch block (cLBBB). This study aimed to determine the predictive value of SF for reduction of left ventricular (LV) global systolic function using 2D speckle-tracking echocardiography (2D STE) in cLBBB patients.Methods and Results:The study group of 41 patients with isolated cLBBB and preserved LV ejection fraction and 41 age- and sex-matched control subjects were studied. The presence of SF and LV global longitudinal strain (GLS) were defined and measured using 2D STE. Multivariate logistic regression analysis identified the presence of SF as an independent factor predicting LV GLS >-20% in isolated cLBBB patients (odds ratio, 1.38; 95% confidence interval, 1.10-1.72; P=0.005). LV GLS in cLBBB patients with SF further decreased over time, whereas LV GLS did not decrease in patients without SF. The presence of SF was shown to be an independent factor predicting the reduction of LV global systolic function (relative reduction in LV GLS >15% from baseline to 2-year follow-up) (odds ratio, 1.27; 95% confidence interval, 1.06-1.50; P=0.008).

CONCLUSIONS: Assessment of SF by 2D STE may be an easy and effective method of predicting the reduction in LV global systolic function in isolated cLBBB patients.