Is A Pacemaker Usually Put In After Aortic Valve Replacement I Don't Understand How This Works? Please Read This !?

I don't understand how this works? Please read this !? - is a pacemaker usually put in after aortic valve replacement

I have a geography test, and we have to write a story about our own journey to the center of the earth. Normally, I think it would be fun, but we need to add geographic data on the basis of the land and that. We saw a film entitled The heart and allowed us to borrow some ideas from the movie and put them in our test. I saw the movie on Wikipedia, and looked at the act and said:
If 32 people in Boston Mysterious Drop Dead, scientist Dr. Josh Keyes (Aaron Eckhart) and Serge Leveque are called upon to investigate and discovered that all pacemaker has clearly not more. A little later lost flocks of pigeons in Trafalgar Square in London navigate their ability to crash into buildings, people and vehicles, and the Space Shuttle EndTake your emergency landing due to an unknown error. Discovered after these events, the scientists of Keyes and Conrad Zimsky (Stanley Tucci), a copy that is the molten heart of the earth gradually to a standstill and without rotation vanishes, the electromagnetic field that reveals the area of sunlight filtered and not burn anything or anyone suspended.
I do not understand how the Earth's core could affect pigeons and pacemakers. Please can someone me a simple explanation?
This is a little long.