I am 67 years old, male, average height and weight. For the past several years I occasionally experience a rapid heart rate, 120+, shortness of breath, lightheadedness, occasionally joint pain, and fatigue that makes it difficult to walk up a single flight of stairs. It lasts for between 4 hours to 12 hours. During this time I lack strength, and generally feel as though I have the flu. I feel nauseous but never feel that I am about to vomit. I have had a stress test, by my doctor, but no obvious blockage. He wanted me to have a blood test, but I have significant anxiety about needles, not the pain associated with drawing blood, but the thought of needles. Aside from blood work, where else would I be looking?