Heart Failure NYHA Class III and Ambulatory IV Clinical Trial
Official title:
Clinical Trial of the SonRtip Lead and Automatic AV-VV Optimization Algorithm in the PARADYM RF SonR CRT-D
The objective of this study is to assess the safety and effectiveness of the automatic
atrioventricular (AV) delay and interventricular (VV) delay optimization algorithm used in
the PARADYM RF SONR Cardiac Resynchronization Therapy with Defibrillation (CRT-D) device
(Model 9770) in combination with the SonRtip Lead, which includes a SonR sensor in the tip of
the atrial pacing lead, and compatible SmartView programming software.
This study will evaluate the effectiveness of the automatic optimization algorithm in
increasing the rate of patients responding to the therapy as compared to an echocardiographic
optimization method.
This study will also evaluate the safety and effectiveness of the SonRtip atrial pacing lead.
Since the introduction of cardiac resynchronization therapy (CRT) on a large scale, it has
been observed that approximately 30% of recipient patients are non-responsive to therapy.
This non-responsiveness can be decreased by optimizing the device programming, particularly
the stimulation rate, paced and sensed atrioventricular (AV) delay, and the interventricular
(VV) delay.
All CRT patients need a 100% rate of ventricular capture, but beyond this the achievement of
therapy effectiveness requires the identification of the optimal pacing configuration, which
varies among patients. The optimization of CRT systems, usually based on ultrasound imaging
is time-consuming and the number of patients in need of multiple optimization procedures due
to ventricular remodeling is growing rapidly.
The mechanical effects of a more coordinated contraction result in a shortening of the
isovolumetric contraction phase and the pre-ejection time, and an increase in LV dP/dt
(change in left ventricular pressure over time. The concept of measuring contractility with
an implantable accelerometer was first clinically validated through a multicenter study on a
rate responsive pacing system (BEST - Living from SORIN Biomedica) in 1996. This study
positively demonstrates that measurement of Peak Endocardial Acceleration signal (called PEA
or SonR) is feasible and reliable in the long-term, both for the purpose of rate response and
as a hemodynamic monitor of cardiac function.
More recent clinical studies have demonstrated that optimal VV and AV Delays determined using
algorithms based on SonR signal analysis (SonR method) are correlated with the highest
hemodynamic improvement and lead to significant clinical benefit for the patients, thus
reducing the rate of non-responsiveness to CRT therapy.
Therefore, automatic AV and VV delay optimization in patients with CRT devices could benefit
both the patient and physician.
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