title: Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block.
abstract: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease.
  
  
  
  We sought to investigate rubidium-82 (82Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block.
  
  
  
  Thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress 82Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal 82Rb-positron emission tomography studies and without left bundle branch block (GII).
  
  
  
  Stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p<0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001).
  
  
  
  The data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by 82Rb-positron emission tomography imaging may be useful in identifying coronary artery disease in patients with left bundle branch block.
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Andréa
authors.initials: A
authors.lastname: Falcão
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: William
authors.initials: W
authors.lastname: Chalela
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Maria Clementina
authors.initials: MC
authors.lastname: Giorgi
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Imada
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: José
authors.initials: J
authors.lastname: Soares
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Renata
authors.initials: R
authors.lastname: Do Val
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Oliveira
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Marisa
authors.initials: M
authors.lastname: Izaki
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: Roberto Kalil
authors.initials: RK
authors.lastname: Kalil Filho
authors.affiliation: Serviço de Medicina Nuclear e Imagem Molecular, Instituto do Coração (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil.
authors.forename: José C
authors.initials: JC
authors.lastname: Meneghetti
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D012414:Rubidium Radioisotopes; D013318:Stroke Volume / Q000502:physiology
chemical_list: D012414:Rubidium Radioisotopes