Syncope: Pacing or Recording in the Later Years

Canadian Institutes of Health Research (CIHR)120 enrolled

Overview

Syncope affects about 50% of Canadians, is the cause of 1 - 2% of all emergency room visits, and probably is responsible for CDN $250 million in health care spending each year. It is associated with decreased quality of life, trauma, loss of employment, and limitations in daily activities. It is a particular problem for older people, partly because of increased frailty, and partly because of a difficult differential diagnosis. One of the causes in older adults is intermittent complete heart block in the setting of bifascicular heart block, but they may also faint due to a variety of tachyarrhythmias, sick sinus syndrome, and several neurally mediated syncopes. Often treatment decisions should be made before the true cause is apparent.

There are two general approaches to the patient with syncope and bifascicular block, a common substrate for intermittent heart block. The first is to assume that intermittent heart block is the cause, and simply implant a pacemaker. The second is to implant a digital ECG loop recorder with a lifespan of 2 - 3 years, determine the rhythm abnormalities during the next faint, and treat accordingly. Both approaches expose patients to a risk of fainting and its sequelae, and both carry device-related complications.Which approach is superior is unknown.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

120

Conditions

Syncope Heart Block

Interventions

pacemakerPROCEDURE

A single or dual chamber pacemaker will be implanted according to the manufacturer's instructions for use with standard techniques. Either a single or dual chamber pacemaker will be permitted according to local practice unless the patient is in chronic or persistent atrial fibrillation, in which case a single chamber pacemaker will be used. The pacemaker configuration will be at the discretion of the investigator. Single chamber ventricular pacemakers will be programmed to activity responsiveness off in VVI mode, rates 50-120 bpm. Dual chamber pacemaker programming will be to DDD mode (50-120) with mode switch on.

implantable loop recorderPROCEDURE

The implantable loop recorder will be programmed for automatic detection using settings of Low Heart Rate \<50 bpm, High Heart Rate \>165 bpm, and Pause \> 3 seconds.

Eligibility

Sex: ALL

Medical Language ↔ Plain English

Inclusion Criteria: -Patients are eligible if they have: * \>1 syncopal spell within 1 year preceding enrollment, and * bifascicular block on a 12-lead ECG, and * Age \> 50 years and * written informed consent. Syncope will be defined based on history using a standardized form. Exclusion Criteria: -Patients will be excluded if they have criteria related to study strategies, including: 1. previous pacemaker, ICD, or Implantable Loop Recorder in situ, 2. ACC/AHA/HRS Class I indication for permanent pacing or ICD implantation, 3. left ventricular ejection fraction \< 35% mandating ICD therapy, 4. contra-indication to a transvenous pacemaker such as artificial tricuspid valve or active sepsis. -Patients will also be excluded if a potential competing cause of syncope poses a threat to life, such as: 5. hypertrophic cardiomyopathy, 6. documented sustained ventricular tachycardia or 7. inducible, sustained monomorphic ventricular tachycardia on EP study. -They will be excluded if they have: 8. a history of myocardial infarction within 3 months prior to enrollment, and 9. a major chronic co-morbid medical condition that would preclude 24 months of follow-up.

Locations (17)

Vanderbilt University

Nashville, Tennessee, United States

University of Calgary

Calgary, Alberta, Canada

Royal Alexandra Hospital

Edmonton, Alberta, Canada

Victoria Heart Institute

Victoria, British Columbia, Canada

St. Boniface Hospital

Winnipeg, Manitoba, Canada

Horizon Health Network New Brunswick

Saint John, New Brunswick, Canada

Mc Master University

Hamilton, Ontario, Canada

Queen's University

Kingston, Ontario, Canada

London Health Sciences Centre

London, Ontario, Canada

Montreal Heart Institute

Montreal, Quebec, Canada

...and 7 more locations

Outcomes

Primary Outcomes

The primary outcome measure will be a composite of Major Adverse Study-Related Events (MASRE) in a 2-year observation period.

MASRE will capture the major consequences ensuing from both strategies, including 1) syncope, 2) symptomatic bradycardias, 3) asymptomatic complete heart block, 4) acute and chronic pacemaker and ILR complications, and 5) death.

Time frame: 2 years

Secondary Outcomes

Secondary outcome measures will include total number of syncopal spells.

Time frame: 2 years

Secondary outcome measures will include the likelihood of a first recurrence of syncope.

Time frame: 2 years

Secondary outcome measures will include the physical trauma due to syncope.

Time frame: 2 years

Secondary outcome measures will include quality of life of the participants.

Time frame: 2 years