Impact of interventricular lead distance and the decrease in septal-to-lateral delay on response to cardiac resynchronization therapy

Abstract

Larger interlead distance on the lateral thoracic X-ray, associated with positioning of the left ventricular lead in the posterior position, is associated with response after 6 months of follow-up. Furthermore, diminishing the septal-to-lateral delay is predictive for response.

Pacing Inter-lead Fluoroscopic RAO and LAO Distance and Cardiac Resynchronization Therapy Response

“…In a study by Buck and co-workers, the same methods were used to measure Inter-lead distance: the study outcomes were assessed by means of 6-month echocardiographic follow-up examination, to determine the persistence of inter-ventricular and intra-ventricular mechanical delay. They found that a more posterior positioning of the LV lead correlated with a reduction in intra-ventricular dissynchrony [1]. The method of measuring the Inter-lead distance used in all the above studies allowed the authors to conclude that an antero-posterior separation (i.e.…”

“…These studies have also assessed echocardiographic endpoints, such as reverse remodeling features of LV and mitral regurgitation. However, depending on the criteria used, 20% to 40% of patients may not respond to CRT [1][2][3]. The eligibility criteria for CRT include clinical, TTE and ECG parameters.…”

“…Recently, radiological ILD (right to left ventricular leads), which is related to the LV lead position, has been assessed in terms of its ability to predict the response to CRT. Measurements have been taken on chest X ray scans in anterior and lateral standard projections [1,6,7]. One of the best echocardiographic projections for detecting intraventricular mechanical delay in clinical practice is the parasternal short axis with M-mode scan, which resembles the plane of view of the LAO projection [8][9][10].…”

Cardiac resynchronisation therapy and the role of optimal device utilisation

“…Selection criteria for cardiac resynchronisation therapy are currently New York Heart Association (NYHA) class III-IV for heart failure despite optimal pharmacological therapy, left ventricular ejection fraction (LVEF) ≤35%, left ventricular end-diastolic diameter (LVEDD) ≥55 mm and a QRS >120 ms. 4 Placement of the LV lead at the point of maximal dyssynchrony improves the response percentage (figure 1). 5,6 However, left ventricular lead positioning at the point of maximal dyssynchrony can be difficult to achieve due to the fixed anatomy of the coronary sinus and its branches. 6 If a patient is a non-responder, defined as a decrease in left ventricular end-systolic volume (LVESV) <10% after six months of follow-up, repositioning may be an option, if the patient otherwise seems a good candidate for CRT.…”

“…5,6 However, left ventricular lead positioning at the point of maximal dyssynchrony can be difficult to achieve due to the fixed anatomy of the coronary sinus and its branches. 6 If a patient is a non-responder, defined as a decrease in left ventricular end-systolic volume (LVESV) <10% after six months of follow-up, repositioning may be an option, if the patient otherwise seems a good candidate for CRT. Ultimately, a guided epicardial lead positioning may be an option.…”