Impact of the Pulmonary Vein Isolation on Exercise Capacity in Patients With Chronic Atrial Fibrillation

III. Goals of the Project The purpose of this study is to determine whether pulmonary vein
isolation with radiofrequency ablation will improve exercise capacity and endothelial
function in patients with chronic atrial fibrillation. We hypothesize that exercise capacity
and endothelial function will improve in patients with chronic atrial fibrillation following
pulmonary vein isolation.

IV. Background and Significance:

Easy fatigability is a frequent complaint in patients with atrial fibrillation (AF). Prior
studies have demonstrated that exercise capacity in patients with "lone atrial fibrillation"
is less than that in healthy matched controls. Other investigators have also shown the
adverse effect of AF by comparing peak oxygen uptake VO2 prior to and after cardioversion. At
present, the majority of studies have focused on patients in whom with AF with either mild
cardiovascular disease or congestive failure. No study to date has assessed if pulmonary vein
isolation (PVI) via intracardiac ablation is able to improve exercise capacity in patients
with chronic LSP-AF.

This prospective registry will assess exercise capacity in patients with chronic AF (CAF)
over a minimum period of 3 months; prior to and after PVI. Chronic AF is defined as those
patients who have an unsuccessful cardioversion and/or an ongoing AF episode (e.g. a year or
more). The observed results will be used to establish a better understanding of overall
quality of life and exercise tolerance prior to and after ablation. This registry may be
further expanded in the future and in a second study to assess exercise tolerance in patients
with CAF who have been treated with alternative treatment strategies. The findings from this
study may begin to pave the way for future clinical practice changes to best manage patients
with CAF.

Description of the procedures: Patients will be required to fast and refrain from smoking at
least 4 hours prior to each testing session.

Arterial Stiffness Arterial stiffness will be measured non-invasively. Two indices of
arterial stiffness will be calculated including carotid augmentation index and aortic pulse
wave velocity after the subject has assumed the supine position for at least 10 minutes.
Blood pressure cuffs will be placed on both arms and legs, and ECG sensors will be placed on
both wrists. Carotid augmentation index will be calculated as the ratio of the amplitude of
the pressure wave above its systolic shoulder to the total pulse pressure. Aortic pulse wave
velocity will be calculated by dividing the distance (carotid to femoral artery) by the
transit time (time delay between the carotid and femoral "foot" waveforms).

Endothelial Health The VENDYS 5000 BCTM (Endothelix, Houston, TX) is an FDA approved device
that will be used to measure vascular responsiveness, which is an index of endothelial
function. It measures changes in skin temperature of the fingertip in response to changes in
blood flow in the arm induced by a 5-minute cuff occlusion, and provides information about
vascular health.

The subjects will be seated for this test with a cuff fixed around the upper right arm and
VENDYS probes on the index fingers of both hands. Fingertip temperatures will be measured
throughout the procedure until 3 minutes after deflation of the cuff. Baseline fingertip
temperature will be measured for 3 minutes before cuff inflation. Following baseline
measures, the cuff will rapidly inflate to 200 mmHg or 50 mmHg above resting systolic blood
pressure and will remain inflated for 5 minutes. During this time, the fingertip temperature
will fall due to the occlusion of blood flow. After 5 minutes, the cuff will rapidly deflate
allowing blood flow to return to the arm. Skin temperature will be measured constantly for 3
minutes.

Exercise Capacity Subjects will perform a modified version of the Balke2 incremental
treadmill exercise test. The test begins with a 0% grade at a constant speed of 3.0 mph. The
grade will be increased by 1% every minute while the speed remains constant. Oxygen
consumption, heart rate, and ratings and perceived exertion (Borg Scale) will be measured
throughout the test and total exercise time to exhaustion will be recorded. Oxygen
consumption will be measured with a metabolic cart while the subjects breathe through a mouth
piece. Blood pressures and ECG will be monitored continuously.

Quality of Life Assessment The MOS 36-short form is a multi-purpose, short-form health survey
with only 36 questions. It yields an 8-scale profile of functional health and well-being
scores as well as psychometrically-based physical and mental health summary measures and a
preference-based health utility index. It is a generic measure, as opposed to one that
targets a specific age, disease, or treatment group. Accordingly, the MOS-36 has proven
useful in surveys of general and specific populations, comparing the relative burden of
diseases, and in differentiating the health benefits produced by a wide range of different
treatments.

Inclusion Criteria:

- Asymptomatic LSP-AF patients undergoing first catheter ablation

- > 18-80 years

- Ability to give consent

Exclusion Criteria:

- Low LVEF

- Inability to comply with follow-up testing