Tragus Stimulation to Prevent Atrial Fibrillation After Cardiac Surgery

This is a single-blind study where patients will be randomized tragus stimulation versus sham
procedure and remain blinded to their treatment allocation. Both treatment options will
utilize similar equipment, namely the use of alligator clips which will be placed on the
tragus and earlobe of the right ear for patients. The distinction is only that in patients
assigned to tragus stimulation, they will be initiated on therapy at the time of device
placement.

Prior to cardiac surgery, the discomfort threshold of both left and righ tragus stimulation
will be determined for all participating patients. Intermittent electrode signals, or
microcurrents, are delivered at 20 Hz with100 µsec pulse width with variable microampere (mA)
output. The discomfort threshold is defined as the stimulation intensity in mA at which point
patients experience discomfort. The stimulation intensity used in the study will be set just
below the discomfort threshold. The clip will then be placed on the patient's ear at the end
of surgery. After surgery is completed, the clip will then be removed and replaced on the
opposite ear. Stimulation will then continue, one ear alternating with the other, every 4
hours for a total of 48 hours. It is possible that the threshold can change during the
post-operative period. If the patient shows any sign of discomfort from stimulation, the
intensity of stimulation will be reduced to a level at which signs of discomfort disappears.

Follow-up will be performed with a 14-day event monitor at the time of discharge.
Electrocardiography (ECG) will be performed pre-procedure and prior to hospital discharge.
Echocardiography will be assessed prior to study initiation and when clinically available in
follow-up.

Inclusion Criteria:

1. Patients ≥18 years of age, <90 years of age

2. Estimated life expectancy of at least 1 year at the time of enrollment

3. History of sinus rhythm or paroxysmal atrial fibrillation

Exclusion Criteria:

1. Patients ≥90 years of age, <18 years

2. Patients with known prior history of persistent or permanent AF

3. Atrial Fibrillation occurrence within the last 24 hours of procedure

4. Urgent or Emergency cases

5. Pregnant patients

6. Patients undergoing the following cardiac procedures: heart transplant, pulmonary
thromboendarterectomy, isolated aortic arch procedures, congenital hear disease,
ventricular assist device insertion, extracorporeal membrane oxygenation insertion,
and surgical AF ablation

7. Antiarrhythmics prior to surgery (Class I and Class III)

8. High degree atrioventricular block requiring temporary pacing

9. MAZE procedure