Effects of cardiac resynchronization therapy on myocardial blood flow measured by oxygen-15 water positron emission tomography in idiopathic-dilated cardiomyopathy and left bundle branch block.

Regional and global myocardial blood flow and coronary vascular resistance were determined in patients with idiopathic-dilated cardiomyopathy and left bundle branch block before and during cardiac resynchronization therapy (CRT) using oxygen-15 water positron emission tomography. The investigated parameters did not exhibit regional heterogeneity and were not influenced by CRT. This implies that the beneficial effects of CRT do not require additional oxygen demand or regional reallocation of oxidative metabolism.