[Myocardial perfusion with Tc-99M sestamibi and dipyridamole, and SPECT images during complete block of the left branch of the bundle of his].

AIM: To review the results of myocardial perfusion during rest and post-pharmacological stress induced by dipyridamole and analyze the SPECT images in patients with complete left bundle branch block LBBB, comparing the results in the presence of a normal coronary angiographic study and with critical coronary obstructions. METHODS: Results from 50 studies of myocardial perfusion of patients with complete block of the LBBB were reviewed and segmental perfusion was analyzed comparing these results with those obtained with those from the diagnostic coronariography. RESULTS: From the 15 studied patients, divided in two groups, 9 with angiographically normal coronaries and 6 with significant coronary lesions, it was not possible to establish a typical perfusion pattern due to the small size of the sample, revealing that the perfusion defects cannot be explained only by the electrocardiographic alterations since other factors participate, such as left ventricular telediastolic hypertension on the interventricular septum as a consequence of the loss of synchrony in ventricular contraction. CONCLUSIONS: Regional myocardial perfusion in patients with complete block of the LBBB is altered in 95% of the cases without relation with the presence of significant coronary alterations.