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Effect of Closed Loop Pacemaker Treatment on Recurrent Vasovagal Syncope

This study has been completed.
Aarhus University Hospital
Biotronik SE & Co. KG
Information provided by:
Aarhus University Hospital Skejby Identifier:
First received: February 15, 2006
Last updated: March 31, 2010
Last verified: March 2010
The main purpose is to prevent syncope in patients with recurrent syncopal episodes caused by malignant vasovagal faints and bradycardia. Patients are treated by a special pacemaker (closed loop stimulation [CLS]) which can potentially identify an incipient attack and prevent syncope by pacing.

Condition Intervention
Vasovagal Syncope
Device: Pacemaker treatment, pacemaker programmed as active = CLS
Device: Pacemaker, programmed as passive = VVI 30 beats per minute (bpm)

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: SCANdinavian Vasovagal SYNCope Pacemaker Investigation (SCANSYNC)

Resource links provided by NLM:

Further study details as provided by Aarhus University Hospital Skejby:

Primary Outcome Measures:
  • Recurrence of syncope, active (CLS pacing) versus passive (VVI=30) pacing period [ Time Frame: 12 months + 12 months ]

Secondary Outcome Measures:
  • Number of syncopal and presyncopal episodes, active versus passive pacing period [ Time Frame: 12 months+12 months ]
  • Quality of life, active versus passive pacing period [ Time Frame: 12 months+12 months ]

Estimated Enrollment: 100
Study Start Date: February 2006
Study Completion Date: March 2010
Primary Completion Date: March 2010 (Final data collection date for primary outcome measure)
Intervention Details:
    Device: Pacemaker treatment, pacemaker programmed as active = CLS
    Pacemaker treatment with closed loop function(CLS)
    Device: Pacemaker, programmed as passive = VVI 30 beats per minute (bpm)
    pacemaker treatment as VVI 30 bpm
Detailed Description:

The treatment of patients with recurrent syncope of vasovagal origin, not precipitated by usual vasovagal factors, and not associated with structural heart disease, is unsolved. The limitations of the conducted 5 pacemaker studies are a significant placebo effect of pacemaker treatment, underpowering and lack of double blinding. The pacemaker intervention has been accelerated dual chamber pacing at the time of bradycardia, which may be too late. However, a pooling of all data indicate a beneficial effect of pacing.

Vasodilatation is an obligate element of all vasovagal syncopal episodes and in many also an early sign associated with the hyperkinetic empty left ventricle which triggers the reflex wave. The principle in closed loop stimulation (CLS) is a continuous surveillance of the impedance in the right ventricle which correlates highly with myocardial contractility. When contractility is increased significantly atrial pacing with prolonged AV delay is commenced. This principle has been used in chronotropic incompetent patients and in one small study of patients with vasovagal syncope with a positive outcome. The hypothesis is that the CLS will potentially identify an incipient vasovagal attack and be able to prevent the drop in cardiac output and bradycardia by early accelerated pacing.

Patients will be treated 12 months with active pacing (CLS) and then crossed over to 12 months with passive pacing (VVI, 30 bpm).

The study will be double blinded, only a technician will know the status of the pacemaker.


Ages Eligible for Study:   25 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • A clinical problem with vasovagal syncope which motivates considerations concerning pacemaker treatment.
  • A positive tilt-table test.
  • Exclusion of other causes for syncope by a complete diagnostic work-up allowing only minor cardiac abnormalities
  • Syncope for >= 2 years.
  • Number of syncopal episodes >= 3
  • At least 1 instance of syncope within the last 6 months.
  • A positive tilt-table test which reproduces the clinical syncope and is associated with a clearly abnormal haemodynamic response:

    • Vasovagal Syncope International Study (VASIS) type 1 with bradycardia < 40 bpm, or
    • VASIS type 2A, or
    • VASIS type 2B
  • Stable clinical condition
  • Able to accept and follow the protocol and give written consent.

Exclusion Criteria:

  • Conventional indication for pacemaker (i.e. atrioventricular [AV] block)
  • Indication for cardiac resynchronisation therapy (i.e. left bundle branch block [LBBB])
  • Documented atrial fibrillation or flutter
  • Epilepsy
  • Congestive heart failure
  • History of myocardial infarction (MI) or angina pectoris
  • Serious chronic disease, life expectancy < 3 years.
  • Age < 25 years
  • Pregnant and lactating women
  • Participating in other investigation
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Please refer to this study by its identifier: NCT00292825

Henning Mølgaard, MD, DMSc
Århus N, Denmark, 8200
Sponsors and Collaborators
Aarhus University Hospital Skejby
Aarhus University Hospital
Biotronik SE & Co. KG
Principal Investigator: Henning Mølgaard, MD, DMSc Department of Cardiology, Skejby Sygehus, Aarhus University Hospital, Denmark
  More Information

Responsible Party: Henning Mølgaard M.D., DMSc, Aarhus University Hospital, Skejby; Århus, Denmark Identifier: NCT00292825     History of Changes
Other Study ID Numbers: skejbyH
Study First Received: February 15, 2006
Last Updated: March 31, 2010

Keywords provided by Aarhus University Hospital Skejby:
vasovagal syncope
cardioinhibitory syncope
neurocardiogenic syncope
closed loop pacing
tilt table

Additional relevant MeSH terms:
Syncope, Vasovagal
Consciousness Disorders
Neurobehavioral Manifestations
Neurologic Manifestations
Nervous System Diseases
Signs and Symptoms
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases processed this record on April 26, 2017