Potential benefit of optimizing atrioventricular & interventricular delays in patients with cardiac resynchronization
Bozena Urbanek1, Krzysztof Kaczmarek1, Artur Klimczak1
1Department of Electrocardiology, Medical University of Lodz, Lodz, Poland.
Insights
Optimizing atrioventricular delay (AVD) and interventricular delay (VVD) in cardiac resynchronization therapy (CRT) improves cardiac output and reverse left ventricular remodeling. Impedance cardiography (ICG) is a valuable tool for this optimization.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Devices
Background:
- The clinical benefit of optimizing atrioventricular delay (AVD) and interventricular delay (VVD) in cardiac resynchronization therapy (CRT) is not fully established.
- This study investigates the impact of AVD and VVD optimization on key patient parameters post-CRT implantation.
Purpose of the Study:
- To determine the influence of AVD and VVD optimization on hemodynamic, electrical, and echocardiographic parameters in CRT patients.
- To evaluate the effectiveness of impedance cardiography (ICG) for optimizing CRT settings.
Main Methods:
- Fifty-two heart failure patients with left bundle branch block and low ejection fraction received CRT.
- Patients were randomized to an optimized (OPT) or factory setting (FS) group for AVD/VVD.
- Hemodynamic and electrical parameters were assessed early and at 3-month follow-up; echocardiography was performed before and after implantation.
Main Results:
- Early after CRT, the OPT group showed shorter AVD and earlier LV pacing.
- At 3-month follow-up, the OPT group demonstrated improved cardiac output and significant reverse left ventricular remodeling, including reduced LV dimensions and improved LVEF.
- The OPT group also exhibited shorter paced QRS duration compared to the FS group.
Conclusions:
- Optimization of AVD and VVD in CRT using ICG leads to improved cardiac output and reverse left ventricular remodeling.
- ICG is a practical, non-invasive method for optimizing CRT device settings.
Background & Objectives:
The clinical benefit of optimization (OPT) of atrioventricular delay (AVD) and interventricular delay (VVD) in cardiac resynchronization therapy (CRT) remains debatable. This study was aimed to determine the influence of AVD and VVD OPT on selected parameters in patients early after CRT implantation and at mid-term follow up (FU).
Methods:
Fifty two patients (61±10 yr, 23 males) with left bundle branch block, left ventricular ejection fraction (LVEF) ≤35 per cent and heart failure were selected for CRT implantation. Early on the second day (2DFU) after CRT implantation, the patients were assigned to the OPT or the factory setting (FS) group. Haemodynamic and electrical parameters were evaluated at baseline, on 2DFU after CRT and mid-term FU [three-month FU (3MFU)]. Echocardiographic measures were assessed before implantation and at 3MFU. The AVD/VVD was deemed optimal for the highest cardiac output (CO) with impedance cardiography (ICG) monitoring.
Results:
On 2DFU, the AVD was shorter in the OPT group, LV was paced earlier than in FS group and CO was insignificantly higher in OPT group. At 3MFU, improvement of CO was observed only in OPT patients, but the intergroup difference was not significant. At 3MFU in OPT group, reduction of LV in terms of LV end-diastolic diameter (LVeDD), LV end-systolic diameter, LV end-diastolic and systolic volume with the improvement in LVEF was observed. In FS group, only a reduction in LVeDD was present. In OPT group, the paced QRS duration was shorter than in FS group patients.
Interpretation & Conclusions:
CRT OPT of AVD and VVD with ICG was associated with a higher CO and better reverse LV remodelling. CO monitoring with ICG is a simple, non-invasive tool to optimize CRT devices.
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