Abstract 824: Optimal Definition of Left Ventricular Lead Position in Cardiac Resynchronization Therapy by Myocardial Deformation Imaging
Objective. Left ventricular (LV) lead position has crucial impact on cardiac resynchronization therapy (CRT) success. This study compared fluoroscopy and myocardial deformation imaging for optimal definition of LV lead position.
Methods. In 56 heart failure patients (53±5 years, 34 men) undergoing CRT implantation myocardial deformation imaging based on tracking of acoustic markers within 2D echo images (GE Ultrasound) was performed before CRT and directly postoperative on biventricular and LV pacing mode. In a 16 segment model circumferential strain was used to determine the segment with latest peak systolic circumferential strain prior to CRT, considered as the optimal LV lead target. LV lead was defined by (1) fluoroscopy, (2) the maximal temporal difference of peak circumferential strain before-to-on CRT and (3) the earliest peak systolic circumferential strain during LV pacing. For all 3 modalities optimal LV lead position was defined as concordance or immediate neighbouring of the segment with defined LV lead position to the determined optimal target segment. At 12 months follow-up echocardiography was performed to determine improvement in LV function and remodeling.
Results. Conducting a variance analysis the determination of optimal LV position during LV pacing showed the best discriminatory power for LV remodelling (13.86, Standard error (SE) 3.06, p<0.0001 vs. 6.63, SE 3.38, p=0.0551 for biventricular pacing vs. 7.59, SE 3.35, p=0.0273 for fluoroscopy) and LV function improvement (4.64, SE 1.00, p<0.0001 vs. 3.03, SE 1.08, p=0.0723 for biventricular pacing vs. 2.22, SE 1.12, p=0.0528 for fluoroscopy).
Conclusions. Analysis of circumferential strain imaging during LV pacing allows improved determination of the LV lead position in CRT. Improvement in LV function and remodeling as indicators of optimal LV lead position can be best predicited using LV lead position determined by myocardial deformation imaging during LV pacing.