Selected Site Pacing to Avoid Phrenic Nerve Stimulation in Cardiac Resynchronization Patients With Quadripolar Left Ventricular Leads

Study Overview
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Brief Summary
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Cardiac resynchronization (CRT) therapy is well established for treatment of patients with severe heartfailure, reduced left ventricular (LV) function and ventricular dyssynchrony. Roughly 1/3 of CRT patients do not improve after CRT implant. One possible reason is interruption of biventricular pacing. This might be caused by several conditions, including elevated left ventricular (LV) pacing thresholds or presence of phrenic nerve stimulation (PNS). CRT devices with quadripolar LV leads offer 10 LV pacing vectors to choose from. It's the aim of this prospective observational study to investigate efficacy and reliability of cardiac resynchronization therapy (CRT) with quadripolar left ventricular leads. Hypothesis: In more than 90% of patients, who received a CRT system with quadripolar LV lead, at least one acceptable LV lead vector is available.

Detailed Description
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Definition of an acceptable lead vector: Any LV pacing vector that complies in both tested body positions (left lateral position and sitting) with both criteria: Phrenic nerve stimulation threshold is at least twice as high as LV pacing threshold LV pacing threshold is less or equals 2.5Volts (V) @0.5 milliseconds (ms)

Official Title
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Effectiveness and Reliability of Selected Site Pacing for Avoidance of Phrenic Nerve Stimulation in CRT Patients With Quadripolar LV Leads

Conditions
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Heart Failure

Intervention / Treatment
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* Device: quadripolar LV lead (Quartet)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Indication for implantation of a CRT-D Age >= 18 years Written informed consent Exclusion Criteria: Already implanted LV or coronary sinus lead Previous unsuccessful LV lead implant attempt Patient is eligible for heart transplantation Comorbidities that results in life expectancy of less than 12 months Known pregnancy Inability to provide written patient informed consent Participation to another study with active treatment arm (i.e. randomized studies etc...) Patient is not willing or is not able to visit the study center for the study assessments within the first 3 months after implant Patient is not able to understand or answer the quality of life questionaire

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Quadripolar lead<br>All participants receive a CRT-D system with quadripolar lead | Device: quadripolar LV lead (Quartet)<br>* All participants will receive CRT-D system with a quadripolar lead. This lead offers 10 LV lead vectors to choose from<br>* Other names: Quartet;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of patients with at least one acceptable lead vector | Definition of acceptable lead vector: Any LV vector that complies in both tested body positions with both criteria: Phrenic nerve stimulation threshold is at least twice as high as LV pacing threshold LV pacing threshold is less or equals 2.5V@0.5ms | Pre hospital discharge (PHD) to 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of Life | Minnesota living with heart failure questionaire | Baseline to 3 months | 
| Phrenic nerve stimulation (PNS) | Incidence of PNS per LV pacing vector Freedom from PNS for the permanently programmed LV vector | PHD to 3 months | 
| LV pacing thresholds | LV pacing thresholds per LV vector Incidence of elevated (>2.5V/0.5ms) LV pacing thresholds per LV vector | PHD to 3 months | 
| Number of acceptable LV lead vectors per patient |  | PHD to 3 months | 
| Finally programmed LV lead vector | Need for reprogramming Percentage of patients with conventional (bipolar) and extended (quadripolar) LV vectors | PHD to 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hear Failure, Cardiac resynchronization, CRT-D, quadripolar