CompletedPhase 4

Spontaneous Atrio Ventricular Conduction Preservation

Belgium, France, Germany622 participantsStarted 2003-11

Plain-language summary

In case of sinus node dysfunction, it is often necessary to choose the safer option provided by a DDD pacemaker even though the most appropriate mode of pacing is AAI mode. In addition to saving energy, the latter mode allows spontaneous ventricular activation, the haemodynamic consequences of which are, in most cases, better than those obtained with dual chamber pacing. Recent studies as the MOST study suggest also that ventricular desynchronization imposed by right ventricular apical pacing even when AV synchrony is preserved increases the risk of atrial fibrillation in patients with SND. Similar results were already given by anterior studies (PIPAF) which, taking into account the percentage of ventricular pacing, suggested that AF prevention algorithm in combination with a preserved native conduction are efficient in reducing AF burden. However, current practice is to implant a dual chamber pacemaker to prevent the risk of atrioventricular block (AVB) even if DDDR pacing with a fixed long AV delay was found inefficient in reducing ventricular pacing and was associated with a high risk of arrhythmias. The Symphony 2550 cardiac pacemaker offers pacing modes that automatically switch from AAI(R) mode to DDD(R) or DDI(R) in event of severe atrioventricular conduction disorder, irrespective of whether or not these are accompanied by an atrial arrhythmia, returning spontaneously to AAI(R) mode as soon as the spontaneous AV conduction has resumed. These 2 particular modes are called the AAI SafeR and DDD/AMC (R) mode. The main differences between both modes are that (i) AAI SafeR does not trigger any AV Delay after a sensed or paced atrial event which allows long PR intervals or even limited ventricular pauses with no switch to DDD(R), while (ii) DDD/AMC (R) is able to optimize AV Delay after switching to DDD(R) according to measured spontaneous conduction times and to provide an acceleration in case of vaso-vagal syndrome. This pacing mode has previously been assessed in clinical studies. This study intends to demonstrate that the automatic modes switching significantly reduce the percentage of ventricular pacing in patients implanted with a spontaneous AV conduction and reduce the occurrence of atrial arrhythmias, on a mid-term follow-up period, in comparison to standard DDD pacing with long AVDelay.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Patient has been primo-implanted with a Symphony™ 2550 or 2450 devices for less than 3 months * Patient with a normal spontaneous AV conduction at rest (PR \< 250 ms) * Patient implanted for Sinus Node Dysfunction, Braycardia-Tachycardia Syndrome, carotid sinus syndrome/ vaso vagal syndrome or paroxistic AV Block * Patient implanted with a bipolar right-atrial lead and ventricular lead available in the local market * Patient has signed a consent form after having received the appropriate information Exclusion Criteria: * Permanent 1st, 2nd or 3rd AV block * Patient having a medical status complying with one of the following cases * patient suffering from sustained ventricular arrhythmias * patient having sustained a myocardial infarction within the last month * patient having undergone cardiac surgery within the last month * patient suffering from severe aortic stenosis * patient suffering from unstable angina pectoris * patient presents with permanent atrial arrhythmias * Patient is not able to understand the study objectives and protocol or refuses to co-operate * Patient is not available for scheduled follow-up * Patient has a life expectancy less than one year * Patient is included into another clinical study * Patient is minor or a pregnant woman

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

mean percentage of ventricular pacing between the randomized branches on a two-months period (M3 visit)

Timeframe: 2 months

mean percentage of ventricular pacing between the studied groups during the whole study (up to 1 year).

Timeframe: 12 months

Trial details

NCT IDNCT00655213

SponsorLivaNova

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2006-12

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