Cardio-neural Pacing to Modulate AV Conduction in Persistent AF Patients - a Feasibility Study

This is a prospective cohort study. 10 patients with persistent atrial fibrillation with pacing indication will be recruited. They are all scheduled to undergo permanent transvenous pacemakers according to clinical need. Informed consent will be signed before procedure. Arterial line will be inserted for monitoring of blood pressure. After routine ventricular lead implantation, a coronary sinus sheath (attain command or deflectable) will be delivered to RA septum, posterior to CS ostium, at the expected location of parasympathetic ganglion plexus. Pace mapping will be performed with a pacing lead (such as Select Secure 3830) at 30Hz, variable amplitude (20, 10, 5V) at 1ms pulse width. An electrophysiology catheter may be used where necessary for pace-mapping the response. At the site where lowest output can generate 30% prolongation of ventricular CL, the lead is fixed for 2-5mm depth. The output is tested again to achieve 50% prolongation of ventricular CL (at 20, 10, 5, 2, 1V). Fluoroscopic image will be collected with contrast injection at the sheath. Repositioning of lead can be performed if the rate suppression cannot be achieved with 3V@0.4ms. Eventually, the implanted lead will serve as an atrial sensing and pacing lead and will not be removed at the end of procedure. Patient will be connected to a dual chamber pacemaker with device programming per usual clinical care. Patients will be followed up for 3 months.