Analysis of LV lead position in cardiac resynchronization therapy using different imaging modalities

OBJECTIVES: This study sought to evaluate whether left ventricular (LV) lead position in cardiac resynchronization therapy (CRT) can be determined by myocardial deformation imaging during LV pacing and to compare imaging techniques for analysis of LV lead position.

BACKGROUND: LV lead position has a significant impact on effectiveness of CRT, but clinically applicable methods to determine LV lead position are less defined.

METHODS: In 56 patients (53 +/- 5 years, 34 men) undergoing CRT, fluoroscopy and 2 myocardial deformation imaging-based approaches were applied to determine the LV lead position. Myocardial deformation imaging-based techniques were used to determine 1) the segment with maximal temporal difference of peak circumferential strain before and while on biventricular CRT; and 2) the segment with earliest peak systolic circumferential strain during pure LV pacing. Twelve-month echocardiography was performed to determine LV remodeling and improvement in function. Optimal LV lead position was defined as concordance or immediate neighboring of the determined LV lead position to the segment with latest systolic strain prior to CRT.

RESULTS: LV lead position determined during LV pacing correlated to the position determined by fluoroscopy (kappa = 0.761). Patients with optimal LV lead position had greater improvement in LV ejection fraction and decrease in end-diastolic volume than those with nonoptimal LV lead position (12 +/- 4% vs. 7 +/- 3%, p < 0.001, and 28 +/- 13 ml vs. 14 +/- 8 ml, p < 0.001, respectively). Determination of the LV lead position based on myocardial deformation imaging during LV pacing showed greater discriminatory power for improvement of ejection fraction (difference optimal vs. nonoptimal lead position group: 4.64 +/- 1.01 ml; p < 0.001) than deformation imaging with biventricular pacing (3.03 +/- 1.08 ml; p = 0.007) and fluoroscopy (2.22 +/- 1.12 ml; p = 0.053).

CONCLUSIONS: Myocardial deformation imaging during LV pacing allows determination of the LV lead position in CRT. Improvement in LV function and remodeling as indicators of optimal LV lead position can be best predicted by LV lead position analysis during LV pacing. (Left Ventricular Lead Position in Cardiac Resynchronization Therapy; NCT00748735).