Hibernating myocardium has reduced blood flow at rest that increases with low-dose dobutamine.

The study of Sun and coworkers is important because (1) it provides additional data that HM has an inotropic and an attenuated coronary vasodilator reserve. They also provided data that support the conclusion that with dobutamine, the improvement of abnormal LV wall motion is real in many patients. (2) It emphasizes the possibility of a deleterious effect (infarction) of dobutamine in HM and thus the need for appropriate caution during its use. (3) It provides additional data that confirm that areas of perfusion-metabolism mismatch on PET imaging (HM) are associated with a reduced MBF at rest. However, their conclusions about areas of LV dysfunction with "normal" MBF in coronary artery disease are problematic; therefore, one must be extremely cautious about these conclusions on the basis of the data that are presented.