Pacemaker + Heart Monitor?

I had a pacemaker implanted in February because of bradycardia/SSS. Three-month checkup found everything to be normal. However, over the past 6 months, I have had 3 short episodes of visual disturbance in one eye lasting about 10-15 minutes. Suspecting a TIA, I went to the emergency department immediately after the third episode. Eight hours later, I came away with a whole raft of tests and appointments: transversal echocardiogram, brain MRI, stroke clinic, neurologist, etc. Additionally, I am to wear a cardiac monitor (Rhythmstar) for one whole month. My question is: I already have a pacemaker monitoring my heart; why do I need to wear an additional monitor? Is there some information the additional monitor may yield that the PM will not?