Trial Search Results

The Maintenance of Human Atrial Fibrillation

Atrial fibrillation (AF) is the most prevalent heart rhythm disorder in the United States, affecting 2.5 million individuals in whom it may cause stroke, palpitations, heart failure, and even death. Unfortunately, therapy for AF is limited. Anti-arrhythmic or rate-controlling drugs are poorly tolerated, with frequent side effects and do not reduce stroke risk. Ablation is an emerging, minimally invasive therapy that has attracted considerable attention because it may eliminate AF. Unfortunately, AF ablation is technically challenging, with a success of only 50-70% (versus >90% for other arrhythmias) and serious risks. A major cause of these limitations is that the mechanisms for human AF are not known and thus ablation cannot be directed to them. As a result, AF ablation is empiric and results in extensive destruction of the atrium.

This project will perform research to better understand AF and determine if abnormal activity in small regions or more widespread regions of the heart cause AF. By performing these studies in patients during clinical procedures, this project may lead to a paradigm shift in the understanding and treatment of AF.

Stanford is currently accepting patients for this trial.

Lead Sponsor:

University of California, San Diego

Collaborator: National Heart, Lung, and Blood Institute (NHLBI)

Stanford Investigator(s):





   - patients undergoing electrophysiology study (EPS) for ablation of (a) paroxysmal AF
   (non-rheumatic) whose AF episodes self-terminate in < 7 days, or (b) persistent AF
   (non-rheumatic) whose AF episodes last >or= 7 days but terminate with DC cardioversion
   or anti-arrhythmic drugs and do not recur within 24 hours.

   - AF patients must have failed >or= 1 anti-arrhythmic drug


   - will have a full evaluation focusing on diabetes mellitus, hypertension, coronary
   disease, left ventricular ejection fraction (LVEF). We will document whether AF
   relates to times of vagal activity (meals or sleep) or exercise. We will record the
   use of drugs affecting the renin-aldosterone-angiotensin system (RAAS) and statins,
   that may protect against atrial fibrosis and AF. We will document serum potassium
   level, since slight elevations slow CV in vitro. We will record 12-lead ECG and
   echocardiography for left atrial diameter, and stress test and/or coronary angiography
   if indicated.

   - will have event monitor recordings with daily transmissions for at least one week to
   document AF burden (study subjects) or exclude AF (control subjects).

   - must have with-held amiodarone for > 30 days and other anti-arrhythmic drugs for > 5


   - active coronary ischemia in the past year, since the protocol uses isoproterenol

   - rheumatic valve disease, that leads to distinct AF and increases thromboembolic risk

   - prior ablation or cardiac surgery, that alters atrial electrophysiology

   - LA clot or dense contrast on TEE

   - deranged serum electrolytes, and K+ outside 4.0-5.0 mmol/l

   - left atrial diameter > 60 mm

   - LVEF < 40% or New York Heart Association heart failure > Class II, to exclude
   distinct, heart-failure related remodeling

   - thrombotic disease, venous filters, transient ischemic attack or cerebrovascular
   accident, to minimize additional risk

   - pregnancy, to minimize fluoroscopy. As part of routine clinical care, all female
   patients of childbearing age receive a ß-HCG pregnancy test. Any who test positive
   will not be included in the research study

   - inability or unwillingness to provide informed consent

Ages Eligible for Study

21 Years - N/A

Genders Eligible for Study


Now accepting new patients

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Linda Norton, RN
(650) 725-5597