I am 62 female, non smoker, walked 3 miles a day for 30 years, normal to low blood pressure, normal cholesterol, no chest pains or other heart symptoms, BUT shortness of breath for two years now and getting worse. All tests show strong heart, no arrythmias, no congestive failure etc. Have had EKG, Echocardiogram, Thallium Stress test. All great! Dr. says next step is catheterization and I am hesitant. I have explored pulmonary tests and x rays and all OK there. Is the cath the next logical place to go?