I will copy and paste the answer of one very valuable poster here - Chrisb1. I started for the same reason 1 year ago and had to do bunch of reading to understand what exactly was happening with my body and why my heart was working so hard. This is some of the materials , that helped me :
"Water-Fasting is a proven method of lowering HBP permanently by not only losing weight and easing the burden on your heart muscle, but also by cleaning out the arterial plaque that may be just one of the root causes.