Inclusion Criteria:  Subject is >18 years old Subject is referred for permanent pacemaker implantation with an indication for an atrial lead Subject has either paroxysmal atrial fibrillation or baseline intra-atrial conduction delay (P-wave duration >120ms on a 12-lead ECG) Subject is expected to remain available for standard-of-care pacemaker follow-up visits and study questionnaires  Exclusion Criteria:  Subject has permanent atrial fibrillation or is in atrial fibrillation in the pre-operative area prior to the procedure (inability to assess paced P-wave morphology) Subject has pacemaker implantation prior to planned atrioventricular nodal ablation Subject has resting spontaneous sinus rate >85 beats-per-minute Subject has left ventricular ejection fraction <45% Subject is unable or unwilling to complete baseline or follow up quality of life questionnaires Subject is currently enrolled in a potentially confounding trial Subject is pregnant Subject's anticipated life expectancy is less than 1 year