Pacemaker

My mother-in-law, who will be 95 is April, was recently hospitalized has several episodes of arrhythmia at the hospital.  the doctor recommends a pacemaker.  What are the pros and cons of someone her age to have a pacemaker implanted?

[Cleveland Clinic]

Really this is a question for the implanting doctor to answer, as he know his own rate of complications. In general at our institution the immediate risks are of lung collapse, bleeding in the pocket or around the heart requiring pericadiocentesis ( draining of the blood around the heart) or open heart surgery. This is very rare, occurring less than 1/1000 patients. Long term consequences include infection of the device or leads, requirement of long term follow up. It is generally a very well tolerated procedure and quite safe especially if performed by an electrophysiologist.

[Andy813]

I thought cardiologists did the pacemaker implants.   What is an electrophysiologist?   How do they  differ from  cardiologists?