Abstract 2906: Longitudinal Rotation: An Unrecognized Motion Pattern in Patients with Left Bundle Branch Block and Dilated Cardiomyopathy
Background: We recently observed that the left ventricle (LV) of patients with idiopathic dilated cardiomyopathy (DCM) and left bundle branch block (LBBB) frequently displays clockwise rotation when imaged in a standard 4-chamber echo view. Here we analyze the predictors of this phenomenon.
Methods: We studied 19 DCM patients with LBBB (DCM-LB, age 55.8±7.5 years), 8 DCM patients with QRS duration <120 ms (age 58.1 ±17.5 years), 21 ischemic cardiomyopathy patients with LBBB (ICM-LB)(age 68.8 ± 9.8 years), and 16 controls (age 37.3±13 years). Longitudinal rotation (LR) was assessed from 2 dimensional echocardiography data by Speckle Tracking Imaging algorithm (Echopac PC GE, Medical.)(Figure⇓).
Results: End-systolic volumes (ESV) in DCM-LB (181±93 ml), ICM-LB (142±59) and DCM-N (134±79) groups were similar (p= NS). DCM-LB patients had greater longitudinal rotation than control or ICM-LB patients, (P<0.001, Figure⇓). On multivariate analysis, predictors of longitudinal rotation were; higher ESV (p=0.03), longer QRS duration (p=0.03, and the presence of DCM (p=0.0005). In 42 out of 48 patients with ICM or DCM echocardiography was performed 3–12 months post biventricular pacemaker implantation. In those patients LR correlated significantly with the end systolic volume (ESV) decrease (r=0.31, p= 0.047).
Conclusion: Longitudinal rotation is a previously unrecognized motion pattern. It appears in the presence of non-ischemic LV enlargement with QRS prolongation and is predictive of response to biventricular pacing.