With a long history of heart problems and related operations, I had frequent reminders that the problems were still there. I took several medications to stabilize the heart and two more, Lysinopril and Zettia, to lower blood pressure. After PD diagnosis and, as symptoms worsened, weakness, faintness and dizzy spells developed. These were traced to extremely low blood pressure. We dumped the blood pressure meds and the bp retuned to the normal range. The dizziness disappeared. Not only that but somehow (knock knock!!) the other heart related symptoms seem to have backed off also. I no longer carry Nitro.
There are some interesting studies on the subject. If anyone else has had a similar experience I would like to discuss it.