PO-04-057 ATRIAL FIBRILLATION CURED BY PACEMAKER REPROGRAMMING

Abstract

Atrial fibrillation (AF) is commonly detected by remote monitoring of implanted devices. A common question is whether to start anticoagulation in patients with detected AF at risk of stroke. However, the cause of AF is rarely able to be diagnosed or corrected. Repetitive non-reentrant ventriculoatrial synchrony (RNRVAS) is a pacemaker mediated arrhythmia that can occur in patients with intact ventriculoatrial (VA) conduction. Ventricular pacing with retrograde atrial activation that falls within the PVARP is followed by atrial pacing, often delivered while the atrium is refractory. Retrograde atrial activation from the next ventricular paced beat facilitates a repetitive (but non-reentrant) process. Atrial arrhythmias may occasionally result. To highlight the importance of recognizing and correcting RNRVAS as a cause of device-mediated arrhythmia. NA A 68-year-old man with hypertension and sinus node dysfunction underwent dual chamber pacemaker implant (Abbott Assurity). Device interrogation 5-years later showed repetitive episodes of AF that might warrant anticoagulation. Device tracings revealed RNRVAS: retrograde atrial activation falling in PVARP, followed by competitive sensor driven atrial pacing with non-capture, until a captured atrial event initiated AF (Figure, red arrow). Anticoagulation was deferred in favor of device reprogramming, including: 1) reduction in the lower rate; 2) reduction in paced AV delay; and 3) disabling of rate-response. The patient had no further AF episodes. RNRVAS is largely benign but may facilitate initiation of AF or other supraventricular arrhythmias that lead to symptoms or inappropriate therapy. Both RNRVAS and device-triggered AF may be underrecognized. Current devices do not have automatic diagnostic or treatment algorithms. Therefore, it is important to be aware of RNRVAS triggered AF in patients with a dual-chamber device and newly diagnosed AF. RNRVAS tends to occur with a long programmed AV delay (such as is often used to avoid ventricular pacing) and a relatively fast lower rate. Reprogramming to shorten the AV delay, decrease the lower rate or decrease the PVARP are the primary methods of correction. Awareness of pacemaker triggered AF may help avoid inappropriate initiation of anticoagulation or other therapies.