This is a cardiogram from a patient who was implanted with an Intermedics model 281-05 ventricular pacemaker 5 years before sinus node dysfunction. At the time this EKG was taken the patient was suffering from periods of atrial fibrillation and had been placed on Sotalol. This resulted in shortness of breath. The electrocardiogram is remarkable as it shows 1:1 retrograde conduction from the ventricle to the atrium, which is best seen in the lead II rhythm strip. This retrograde conduction suggested that the patient was suffering from pacemaker syndrome. The patient was implanted with an atrial J lead to which her pacer was attached. There was resolution of her shortness of breath and so far no episodes of atrial fibrillation.