 2. History of moderate to severe bronchospastic lung disease including moderate to severe asthma F. Known allergy to regadenoson or aminophylline. G. Any patient not deemed medically stable by a physician. F. Known or suspected severe symptomatic aortic stenosis. G. Severe hypertrophic obstructive cardiomyopathy. H. Evidence of severe symptomatic heart failure NYHA Class III or IV at the time of the scan. 