Stress Echocardiography Study With Regadenoson

Inclusion Criteria: * Patients with a clinically indicated dobutamine echocardiogram showing normal wall motion at rest and abnormal wall motion with stress * Patients with a clinically indicated dipyridamole echocardiogram showing normal perfusion and wall motion at rest and abnormal perfusion with or without abnormal wall motion with stress Exclusion Criteria: * Any condition precluding the safe administration of dobutamine, dipyridamole or SonoVue for echocardiography * Pregnant or breast-feeding, or (if pre-menopausal), not practicing acceptable method of birth control