My 92 Year Old Mother Has Severe Dementia & 20%

My 92 year old mother has severe dementia & 20% kidney function, she had a pacemaker installed close o 10 years ago & is now using it approximately 90% of the time. She has a personal directive & it has been enacted. I do not wish to have her pacemaker replaced other family members disagree, if this is not replaced what will her end of life potentially look like?