We propose to assess regional myocardial function using gated blood pool imaging acquired by a tomographic technique at rest and during stress in patients with myocardial ischemia (coronary artery disease, hypertrophic cardiomyopathy and microvascular angina). Gender differences in response to exercise and pharmacologic stress will also be evaluated. Normal subjects will be studied in order to establish a control database. Current methods of gated blood pool studies use planar imaging, with its attendant limitations; poor resolution and inadequate separation of the myocardial segments, only one view assessed during exercise and superimposition of overlying structures. Tomographic imaging has the advantages of reconstructing 3-dimensional data of the entire heart with the ability to improve segmental resolution and separate overlapping structures, potentially resulting in increased sensitivity and specificity for detection of disease.

The role of pharmacologic stress will be assessed by comparison with exercise stress, in order to validate its use in subjects unable to exercise and identify gender related differences. Quantitative measures of regional wall motion obtained from tomography will be compared to regions of prior myocardial infarction (if present), and with other modalities for evaluating cardiac structure and function. The diagnostic and prognostic value of tomographic wall motion analysis will be studied in patients with myocardial ischemia, with special emphasis on correlation between physiologic variables of coronary blood flow and metabolic function.