What Causes Left Chest Pain And Breathlessness Despite Taking Micardis For High BP?

Pain under left breast radiating to the side of breast. Sharp stabbing pains. Becoming more often. Also, shortness of breath over last few days. I have been diagnosed recently with high blood pressure - was 180/115! Started HBP medication - Micardis - 3 weeks ago. Not due to see my doctor again until 21/1/15!.Can you please tell me what the possible problems could be. Thank you