Acute Hemodynamic Effect of Left Ventricular Endocardial Pacing in Cardiac Resynchronization Therapy

Abstract

During cardiac resynchronization therapy (CRT) device implantation, left ventricular (LV) lead placement is usually performed by means of a transvenous approach using the tributaries of the coronary sinus (CS). The feasibility of transvenous lead positioning depends on many factors, including venous anatomy, accessibility of the vein, pacing threshold, lead stability, and the absence of phrenic nerve stimulation. 1 Clinical Perspective on p 467Several authors have reported variable individual responses to CRT and have indicated the LV pacing site as a major determinant of the hemodynamic response.2-4 However, in patients receiving biventricular pacing, LV lead positioning varies randomly on account of contingencies, unpredictable anatomic conditions, or technical reasons.Transvenous LV endocardial pacing via transseptal puncture has been implemented in the rare circumstance in which neither the transvenous CS epicardial nor the surgical option is feasible. Indeed, this technique enables the limitations of CS venous anatomy to be overcome and may constitute an alternative method of optimizing lead positioning and improving outcome. Initial experience in early studies with transvenous LV endocardial pacing has yielded promising results. [5][6][7] In the present study, we evaluated the acute hemodynamic effects of CRT through transvenous LV endocardial pacing in heart failure patients by analyzing LV pressure-volume relationships. Methods Patient Selection and ProcedureWe enrolled 12 consecutive heart failure patients with indications for CRT. The Institutional Review Board approved the protocol, and all patients gave written informed consent.Exclusion criteria were the presence of a previously implanted device, valvular insufficiency, or stenosis. The atrial and right ventricular leads were placed in the right atrium and at the apex of the right ventricle, respectively, in patients who were lightly sedated. The LV lead was positioned in the CS and advanced into the lateral or posterolateral vein in accordance with standard procedure. Background-During cardiac resynchronization therapy (CRT) device implantation, the pacing lead is usually positioned in the coronary sinus (CS) to stimulate the left ventricular (LV) epicardium. Transvenous LV endocardial pacing via transseptal puncture has been proposed as an alternative method. In the present study, we evaluated the acute hemodynamic effects of CRT through LV endocardial pacing in heart failure patients by analyzing LV pressure-volume relationships. Methods and Results-LV pressure and volume data were determined via conductance catheter during CRT device implantation in 10 patients. In addition to the standard epicardial CS pacing, the following endocardial LV sites were systematically assessed: the site transmural to the CS lead, the LV apex, the septal midwall, the basal lateral free wall, and the midlateral free wall. Four atrioventricular delays were tested. There was a significant improvement of systolic function with CRT in all LV pacing configurations, wherea...

Development of a Technique for Left Ventricular Endocardial Pacing via Puncture of the Interventricular Septum

“…25 LV endocardial pacing may be superior to epicardial pacing at improving hemodynamic response to CRT. 21,[26][27][28][29][30][31][32][33] In part, this could result from better targeting of lead position because an endocardial approach is not constrained by venous anatomy or phrenic nerve stimulation. The lead tip can be steered to the site of latest electric or mechanical activation or site of maximum acute hemodynamic improvement, provided there is no endocardial scarring.…”

Cardiovascular drug utilization post-implant is related to clinical outcome in heart failure patients receiving cardiac resynchronization therapy

“…CRT has the potential to induce substantial changes in the cardiac function [40], which in turn may influence blood pressure, renal function and fluid status of the patient. It is imperative to make a renewed assessment of fluid status and loop diuretic need, after the expected (potential) remodelling effect of CRT has taken place, in order to re-evaluate the indication and required dosages for the treatment.…”

Cardiac Resynchronization Therapy

“…57,58 In small clinical studies the benefit was less consistent when the endocardial site opposing the CS lead was studied, but other endocardial sites usually provided better hemodynamic effects. 53,59,60 LV endocardial pacing is currently applied using a transatrial septal puncture and advancing the lead through the mitral valve onto the LV endocardial wall in patients with no other options. 61,62 Wider application of LV endocardial pacing awaits novel design of pacing leads or lead delivery systems.…”