Left Ventricular Lead Placement Guided by Reduction in QRS Area

Abstract

Background: Reduction in QRS area after cardiac resynchronization therapy (CRT) is associated with improved long-term clinical outcome. The aim of this study was to investigate whether the reduction in QRS area is associated with hemodynamic improvement by pacing different LV sites and can be used to guide LV lead placement. Methods: Patients with a class Ia/IIa CRT indication were prospectively included from three hospitals. Acute hemodynamic response was assessed as the relative change in maximum rate of rise of left ventricular (LV) pressure (%∆LVdP/dtmax). Change in QRS area (∆QRS area), in QRS duration (∆QRS duration), and %∆LVdP/dtmax were studied in relation to different LV pacing locations within a patient. Results: Data from 52 patients paced at 188 different LV pacing sites were investigated. Lateral LV pacing resulted in a larger %∆LVdP/dtmax than anterior or posterior pacing (p = 0.0007). A similar trend was found for ∆QRS area (p = 0.001) but not for ∆QRS duration (p = 0.23). Pacing from the proximal electrode pair resulted in a larger %∆LVdP/dtmax (p = 0.004), and ∆QRS area (p = 0.003) but not ∆QRS duration (p = 0.77). Within patients, correlation between ∆QRS area and %∆LVdP/dtmax was 0.76 (median, IQR 0.35; 0,89). Conclusion: Within patients, ∆QRS area is associated with %∆LVdP/dtmax at different LV pacing locations. Therefore, QRS area, which is an easily, noninvasively obtainable and objective parameter, may be useful to guide LV lead placement in CRT.

Exploring QRS Area beyond Patient Selection in CRT—Can It Guide Left Ventricular Lead Placement?

“…Within the scope of selecting the right electrodes, the results showed that the pacing of the proximal electrode was accompanied by an increased AHR (p = 0.004) and ∆QRS area (p = 0.003). Again, this correlation did not apply for QRSd (p = 0.77) [42]. These results were confirmed in the aforementioned study by Okafor et al Also using AHR as a surrogate outcome, they found that QRS area reduction (in contrast to baseline QRS area) was significantly associated with ∆LVdP/dt max (r = −0.68; p < 0.001).…”

Fifteen-Year Differences in Indications for Cardiac Resynchronization Therapy in International Guidelines—Insights from the Heart Failure Registries of the European Society of Cardiology

“…In addition to the clinical efficacy of CRT, its cost-effectiveness has been evaluated in several analyses [ 15 , 16 , 17 , 18 , 19 , 20 ]. After reviewing literature that describes years of experience with CRT, the optimal profile of a patient who could benefit most from CRT can be specified ( Figure 1 ) [ 1 , 3 , 7 , 21 , 22 , 23 , 24 ]. Before evaluating the indications for CRT, the patient should receive optimal treatment of HF according to the current best medical knowledge for at least 3 months (or even 6–9 months) [ 1 , 25 ].…”

Special Issue: Latest Advances in Delivery and Outcomes of Cardiac Resynchronization Therapy and Conduction System Pacing

“…The area of latest mechanical activation can be defined by echo or MRI, but this is not easily translated to implantation fluoroscopy [34,35]. The reduction in electrical dyssynchrony as assessed by reduction in vectorcardiographic QRS area could be an attractive target for lead placement strategies [36]. More simple to use would be QRS narrowing by CRT [37]; however, super-response can occur in the absence of a significant reduction in QRS duration.…”