Routine Mini-invasive Electrophysiology Study for Patients Feeling Tachycardia, With a Negative Holter ECG

Study Overview
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Brief Summary
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Patients complaining of tachycardia but with a negative Holter ECG, are for a limited time period offered a simplified electrophysiological(EP) examination. By a full electrophysiological study(EP study)electrodes are introduced for pacing and sensing i all four heart chambers. Where as by the mini invasive EP study only one electrode is introduced to the right atrium. The simplified procedure represent a smaller risk of complications, requires less resources but should yield the same diagnoses in more than 90% of the cases. The study is a feasibility study to see if the procedure can discover arrythmias in a fairly unselected patient population.

Detailed Description
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Sykehuset Telemark performs every year approximately 800 Holter ECG examinations. Approximately 200 of these are on the indications tachycardia, and in about 170 patients the examination does not discover any tachycardia Patients who were examined in the period from August 1. 2004 to November 1. 2005 with a negative Holter are mailed a letter with information of the min invasive electrophysiological examination, and an offer of volunteer participation. Patients given their informed consent are then according to waiting list called for the mini-invasive EP-study. The protocol of the EP stimulation consists of: determination of pacing threshold, pacing with 8 asynchronous beats 600ms and an extrasystole with decremental intervals from 550 ms to 200 ms. The seri is repeated with pacing on 400ms and with two extrasystoles as well as with isoprenaline stimulation.

Official Title
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Mini-invasive Electrophysiology Study as a Routine Examination for Patients Complaining of Tachycardia, But With a Negative Holter ECG.

Conditions
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Pre-excitation Syndromes, Paroxysmal Tachycardia, Atrial Fibrillation, Atrial Flutter, Wolff-Parkinson-White Syndrome

Intervention / Treatment
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* Other: Mini-invasive electrophysiological study
* Other: Atrial pacing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: History of complains of tachycardia No arrythmias detected by a 24 hours Holter ECG Age 19 to 74 years Exclusion Criteria: Patients younger than 18 years Patients older than 75

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Atrial pacing<br>Diagnostic pacing in right heart atrium in order to unmask reentry tachycardia | Other: Mini-invasive electrophysiological study<br>* Transvenous pacing in right heart atrium<br>Other: Atrial pacing<br>* Diagnostic pacing in right heart atrium in order to unmask reentry tachycardia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of tachycardia diagnoses previously not known. | A simple electrophysiologic examination uncovered reentry tachycardia in nine patients and paroxystic atrial flutter in three patients. A total of 56 electrophysiologic examinations were performed, uncovering 12 cases of tachycardia suitable for ablation. Two patients had to undergo DC-conversion, no other complication was observed. Interpretation. A simplified electrophysiologic examination of this group of patients will uncover tachycardia suitable for ablation in approximately 20 % of the patients, and increase diagnostic yield of supraventricular tachycardia by 64 %. | October 2005 to May 2006 | 
| Primary outcome was the diagnosis of supraventricular tachycardia suitable for ablation | Two patients had to undergo DC conversion for A.fib | Oct 2005 - May 2006 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of diagnoses after referral to university ref. centre | 8 patienst were RF abladed in Oslo University Hospital | May 2006 - June 2007 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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paroxysmal tachycardia, Electrophysiological study