Organization of Excitation in People With Atrial Fibrillation

July 14, 2017 updated by: Omer Berenfeld, University of Michigan

Complex Electrograms in Atrial Fibrillation: Spatiotemporal Organization and Mechanistic Insights and Organization in Acute Atrial Fibrillation Post Open Heart Surgery

Atrial fibrillation (AF) is a condition in which the upper chambers of the heart, the atria, undergo an irregular beating rhythm. Despite the fact that AF is the most common type of sustained cardiac rhythm disturbance the investigators still do not understand it entirely and its current therapies are only marginally effective. The overall goal of our project is to determine the organization and mechanisms of electrical activation patterns during AF in humans.

Study Overview

Status

Completed

Conditions

Detailed Description

Experiments in animal hearts demonstrated that some cases of atrial fibrillation (AF) may be maintained by a small number of drivers in the form of self-sustained, reentrant, electrical impulses located in the posterior left atrium (LA) wall, near the pulmonary veins (PV/LA junction). In those experiments, the fastest rotors acted as the highest frequency drivers that maintained the overall activity. This resulted in a hierarchy of local excitation frequencies throughout both atria. More recently, clinical studies have confirmed the existence of a hierarchical organization in the rate of activation of different regions in the atria of patients with paroxysmal and chronic atrial fibrillation. However, the mechanisms underlying such a hierarchical distribution of frequencies in human AF has not been explored. Our project will try to demonstrate the general hypothesis that both local activation frequency and degree of regularity, while different in different parts of the atrium, are distributed non-randomly, with different patterns of distribution in paroxysmal versus chronic AF patients. We further surmise that such patterns are the result of interrupted propagation of impulses emanating from the drivers localized at the site of highest frequency and organization activity, with a gradual reduction of activation frequency as the distance from the driver increases. To test our hypotheses we will use a combination of clinical and numerical studies. For the clinical part we will gather patients data in a collaborative site at Rochester, NY. The data obtained in that site will be analyzed and interpreted at the Institute for Cardiovascular Research in SUNY Upstate Medical University. For the numerical part, simulations on computer models of AF will be performed solely in the Institute for Cardiovascular Research. Our Specific Aims are: 1. Characterize the frequency of activation during AF in patients after heart surgery and relate it to the presence of fibrosis. 2. In computer simulations, to study the mechanisms of initiation and maintenance of AF at the PV/LA junction using three different computer models with increasing anatomical complexity (the description of the computer simulations is available only in the grant application). Successful achievement of our specific aims should help us advance understanding of the mechanisms and manifestations of this complex arrhythmia and may help to directly improve the efficacy of pharmacological and ablative therapies of AF in patients.

Study Type

Observational

Enrollment (Actual)

146

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Michigan
      • Ann Arbor, Michigan, United States, 48109
        • University of Michigan
    • New York
      • Syracuse, New York, United States, 13210
        • SUNY Upstate Medical University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Patients with paroxysmal and chronic atrial fibrilation (AF).

Description

Inclusion Criteria:

  • Clinical indication for curative ablation of AF
  • Patients will be enrolled as they are referred for the ablation therapy or post open heart surgery

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Michigan

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)

Investigators

  • Principal Investigator: Omer Berenfeld, University of Michigan

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

September 1, 2006

Primary Completion (Actual)

August 1, 2011

Study Completion (Actual)

August 1, 2011

Study Registration Dates

First Submitted

March 27, 2009

First Submitted That Met QC Criteria

March 27, 2009

First Posted (Estimate)

March 30, 2009

Study Record Updates

Last Update Posted (Actual)

July 19, 2017

Last Update Submitted That Met QC Criteria

July 14, 2017

Last Verified

July 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 628
  • P01HL039707 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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