angina
"Some months ago I developed chest pain with shortness of breath, it happened mostly on mild exertion and lasted up to half an hour. It was debilitating.

After extensive investigation as an inpatient (including angiogram) I was diagnosed with Microvascular Angina. 

I remember exactly when I started taking Ranolazine, the day afterwards was quite remarkable. Chest pain was reduced and the following day it was reduced further. It was unbelievable, I was so relieved.

I've been on this medication for a couple of months now with no side effects to date. I've had to have a period of reducing it to see how that effects me, I got increased chest pain and shortness of breath when reduced. Once back up to full dose the chest pain is controlled."