What Causes Pulmonary Hypertension Along With Dizzy Spells?

Hi, I was just Dx with Mitral Stenosis and Pulmonary hypertension and was told that I probably had Rheumatic Fever sometime in the pass and like 50% of the people I didn t know I had it. I can not remember ever being that sick or having any throat or Steph infection(only tonsillitis)? I am to have a heart Cath in the near further. Also I have be getting dizzy a lot within the last week; the heart MD stated it might be Vertigo? Anything you can tell me about these condition?