I am sorry to hear of this horrible and complicated situation with your sister. With such a massive heart attack with lots of arrhythmias, it sounds like she should have a Defibrillator (AICD) implanted, rather than a pacemaker. Pacemakers help protect the heart against rhythms that are too slow. They certainly can be implanted in people with "low ejection fractions." However, in people whose ejection fraction is under 30%, in addition to having trouble with "heart failure" (the heart not pumping properly, causing fluid to build up in their lungs, legs, and sometimes other places), they are at risk to have fast or rapid arrhythmias, which require an AICD to protect against. The AICD acts as a pacemaker if it sees slow rhythms, but it can also pace or shock an abnormal rapid rhythm to restore a normal beating of the heart. The SVT with a pulse of 190 is something that an AICD would detect and try to fix, either with pacing or by shocking her heart back to a normal rhythm. The sickest and lowest-ejection-fraction patients are the most likely to require, benefit, and be treated with AICD's. I would suggest double-checking with her Cardiologist or getting a 2nd opinion with another one or possibly an Arrhythmia Specialist. Good luck, I hope she improves. Keep us posted on her progress, or if you have any other Q's.