Ultrasound Research Today is a free monthly online journal that collates and summarizes the latest research about Ultrasound, including details on screening, diagnosis, pregnancy, detection. | ||||||||
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Tissue synchronization imaging and optimal left ventricular pacing site in cardiac resynchronization therapy.Murphy RT, Sigurdsson G, Mulamalla S, Agler D, Popovic ZB, Starling RC, Wilkoff BL, Thomas JD, Grimm RA Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, Ohio, USA. The optimal pacing site in cardiac resynchronization therapy (CRT) remains controversial. Tissue synchronization imaging is a novel echocardiographic technique that color-codes for areas of maximal delay in myocardial velocities. This study aimed to identify whether the left ventricular (LV) pacing lead position in CRT should be guided by a patient's area of maximal mechanical delay. Fifty-four patients with advanced heart failure were assessed echocardiographically before and 6 months after CRT. Response was analyzed according to the relation between the LV lead position and the area of maximal delay to peak velocity by tissue synchronization imaging in the first half of the ejection phase: group 1 (n = 22) had lead placement corresponding to the segment of maximal delay; group 2 (n = 13) had lead placement 1 segment adjacent; and group 3 (n = 19) had lead placement remote from this site. Evidence of LV reverse remodeling and improved systolic function was documented in group 1 (mean percentage decrease in end-systolic volume 23%) more than in group 2 (mean decrease 15%), and more than in group 3 (mean increase 8.9%, p <0.0001 compared with groups 1 and 2). In group 1, 16 of 22 patients had reverse remodeling (>15% decrease in end-systolic volume); reverse remodeling was seen in 7 of 13 patients in group 2 and 1 of 19 in group 3. The placing of the lead position proximal to the site of maximal delay by tissue synchronization imaging was correlated with reverse remodeling (r = 0.449, p = 001). Of 7 patients with delay confined to the septum and anterior wall only, none had evidence of reverse remodeling after CRT. In conclusion, pacing at the site of maximal mechanical delay was associated with reverse remodeling. Individually tailored LV lead positioning should be considered before CRT. Published 26 May 2006 in Am J Cardiol, 97(11): 1615-21.
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