PT - JOURNAL ARTICLE AU - Bernd Nowak AU - Christoph Stellbrink AU - Wolfgang M. Schaefer AU - Anil M. Sinha AU - Ole A. Breithardt AU - Hans-Juergen Kaiser AU - Patrick Reinartz AU - Peter Hanrath AU - Ulrich Buell TI - Comparison of Regional Myocardial Blood Flow and Perfusion in Dilated Cardiomyopathy and Left Bundle Branch Block: Role of Wall Thickening DP - 2004 Mar 01 TA - Journal of Nuclear Medicine PG - 414--418 VI - 45 IP - 3 4099 - http://jnm.snmjournals.org/content/45/3/414.short 4100 - http://jnm.snmjournals.org/content/45/3/414.full SO - J Nucl Med2004 Mar 01; 45 AB - Heterogeneous perfusion in left bundle branch block (LBBB) has been demonstrated by 99mTc-methoxyisobutylisonitrile (MIBI) SPECT. Locally different contraction is also associated with LBBB. Quantitative analysis of myocardial SPECT is influenced by partial-volume effects depending on systolic wall thickening. Therefore, partial-volume effects may mimic perfusion heterogeneity in LBBB. Methods: Fifteen patients with nonischemic dilated cardiomyopathy and LBBB underwent resting 15O-water PET, 99mTc-MIBI SPECT, and gated 18F-FDG PET for analysis of wall thickening. Myocardial blood flow corrected for rate–pressure product (corrMBF), 99mTc-MIBI uptake, and wall thickening were determined in 4 left ventricular wall areas. In 14 patients, M-mode echocardiographic recordings were available for comparison. Results: Homogeneous distribution was found for corrMBF (1.09 ± 0.41 to 1.19 ± 0.31 mL × g−1 × min−1). 99mTc-MIBI uptake and wall thickening were heterogeneous (P < 0.0001), with the lowest values septal (99mTc-MIBI, 65% ± 10%; wall thickening, 16% ± 14%) and the highest lateral (99mTc-MIBI, 84% ± 5%; wall thickening, 55% ± 17%). Similar relationships in systolic wall thickening were observed by M-mode echocardiography (anteroseptal, 20% ± 11%; posterolateral, 37% ± 18%; P < 0.001). Conclusion: Heterogeneity of 99mTc-MIBI uptake in LBBB corresponds to differences in wall thickening and does not reflect distribution of corrMBF. Supplementary analysis of wall thickening is recommended when assessing 99mTc-MIBI SPECT in LBBB.