Journal of the American Society of Echocardiography
Clinical InvestigationLeft Ventricular Dyssynchrony: Repsonse to PacingEffect of Low-Amplitude Two-Dimensional Radial Strain at Left Ventricular Pacing Sites on Response to Cardiac Resynchronization Therapy
Section snippets
Patient Population and Study Protocol
One hundred forty patients in sinus rhythm with left bundle branch block (QRS width ≥ 120 msec), NYHA functional class III or IV heart failure, and impaired LV systolic function (LV ejection fraction ≤ 35%) despite receiving maximally tolerated optimal medical treatment were assessed. The study was conducted in two consecutive groups, with hypothesis testing in the first group (n = 65), to derive the optimal cutoff of low-amplitude radial strain that negatively predicted CRT response
Baseline Characteristics and Response to CRT
At baseline, among the entire study population, the mean age was 71 ± 10 years, with a mean LV ejection fraction of 23 ± 7% and a mean QRS duration of 157 ± 22 msec. Baseline characteristics of all patients and a breakdown of patients in the validation and derivation groups are provided in Table 1.
In the entire study population after 6 months of CRT, NYHA class improved in 95 patients (67.9%), was unchanged in 35 patients, and worsened in eight patients. At follow-up, two patients died of
Discussion
In the present study, we report the detrimental effects on CRT response of the presence of LAS as determined by speckle-tracking radial strain analysis, at the site of LV lead placement. We have derived a cutoff value to define LAS and tested this prospectively in a validation group to demonstrate the significance of radial strain amplitude on CRT response. Multivariate regression analysis suggests that even in the presence of significant LV dyssynchrony, a favorable outcome of CRT is dependent
Conclusions
The presence of low-amplitude 2D radial strain at the LV pacing site has detrimental effects on CRT response despite the presence of LV dyssynchrony or pacing of the latest site of contraction. In the prospective identification of the optimal site for LV lead placement, consideration should be given to the amplitude of 2D radial strain as well as the timing of segmental contraction.
Acknowledgments
We wish to thank Addenbrooke’s Charitable Trust, Papworth Hospital Research and Development Department, and Cambridge Biomedical Research Centre, funded by the UK National Institute for Health Research for their support in conducting this work.
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Real-Time X-MRI-Guided Left Ventricular Lead Implantation for Targeted Delivery of Cardiac Resynchronization Therapy
2017, JACC: Clinical ElectrophysiologyComprehensive use of cardiac computed tomography to guide left ventricular lead placement in cardiac resynchronization therapy
2017, Heart RhythmCitation Excerpt :AHR was compared with CT indices and the sensed QLV interval at each pacing site.14 Patients underwent 6-month follow-up to identify clinical responders via the Packer score15 and echocardiographic response defined as reduction in LV end-systolic volume >15%. The primary end point was cardiac CT–derived regional endocardial strain analysis (SQUEEZ) prediction of the pacing site achieving the optimal AHR.
Better understanding before implanting
2015, International Journal of CardiologyThe association of left ventricular lead position related to regional scar by speckle-tracking echocardiography with clinical outcomes in patients receiving cardiac resynchronization therapy
2014, Journal of the American Society of EchocardiographyUsefulness of echocardiographically guided left ventricular lead placement for cardiac resynchronization therapy in patients with intermediate QRS width and non-left bundle branch block morphology
2014, American Journal of CardiologyCitation Excerpt :No patient had septal or anteroseptal regions as the latest site of mechanical activation. Although a formal quantitative exclusion of scar with a predetermined cutoff was not performed,9,15 the segments with likely scar (thin wall ≤5 mm and an abnormal increase in acoustic reflectance)16 that had very low amplitude strain curves with significant noise were considered as missing data and, therefore, were not selected as a site of latest mechanical activation. Determination of the LV lead position with respect to the site of latest mechanical activation was performed by investigators who were unaware of all patient outcome data.
Incremental value of inefficient deformation indices for predicting response to cardiac resynchronization therapy
2013, Journal of the American Society of EchocardiographyCitation Excerpt :Response to CRT was evaluated in 43 patients because these patients had paired echocardiograms at baseline and 6 months after CRT. Reverse remodeling was defined as a decrease in LV end-systolic volume ≥ 15% at 6-month follow-up.9,10,23 The study protocol was approved by the local institutional review board, and informed consent was obtained from each participant.