title: A new myocardial perfusion scintigraphy stress protocol combining dipyridamole-dobutamine-atropine.
abstract: BACKGROUND
  Pharmacological stress is often used, and the drugs most frequently utilized are dipyridamole (Dip) and dobutamine (Dob). We aimed to evaluate the safety and the results obtained with a new protocol associating Dip, Dob, and atropine, compared with the Dip protocol.
  
  
  METHODS
  Thirty-two patients underwent rest Tl/Dip stress Tc-sestamibi myocardial perfusion tomography on the same day. Dip was administered intravenously (0.56 mg/kg) for 4 min, and Tc-sestamibi was injected 3 min after the end of the Dip injection. On another day, patients received the same Dip dose, immediately followed by the infusion of Dob [20 μg/kg/min for the first 2 min and 40 μg/kg/min in the next 2 min, with atropine (1 mg) given in the interval between the two Dob doses]. Images were acquired with a two-detector camera. In a 17-segment model of the left ventricle, each segment was automatically scored 0-4 (normal to absent radiotracer activity), and perfusion scores were obtained as the sum of stress score and sum of rest segmental score (SSS and SRS, respectively) and the difference between them [summed difference score (SDS)]. All scans were interpreted by two experienced physicians as either definitely normal, probably normal, probably abnormal, or definitely abnormal.
  
  
  RESULTS
  No serious complication was found independently of the protocol used. Heart rate and systolic and diastolic blood pressure were similar in both protocols at the basal level. Maximum heart rate (126 ± 21 vs. 82.7 ± 13.6, P<0.001) and the double product (18816 ± 4194 vs. 11449 ± 2438, P<0.001) showed a significant increase in the tests that used Dob and atropine compared with the Dip protocol. Stress studies with Dip-Dob had higher SSS compared with the Dip protocol (9.4 ± 10.1 vs. 7.7 ± 8.8, P<0.001). SDS was also higher in the Dip-Dob protocol than in the Dip protocol (6.1 ± 6.8 and 4.8 ± 5.8, respectively, P< 0.001).
  
  
  CONCLUSIONS
  This work shows that a new protocol of pharmacological stress with a combination of Dip, Dob, and atropine is safe, easy to administer, and results in larger stress-induced defect size and reversibility of myocardial perfusion.
authors: Universitary Hospital Clementino Fraga Filho, School of Medicine, Federal University of Rio de Janeiro, Brazil. ronlima@hotmail.com
authors: Ronaldo Souza Leão
authors: RS
authors: Lima
authors: Andrea
authors: A
authors: De Lorenzo
authors: Luiz S
authors: LS
authors: Machado
authors: Bernardo N
authors: BN
authors: Oliveira
authors: Marcos P
authors: MP
authors: Pellini
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents; D001285:Atropine; D002316:Cardiotonic Agents; D004176:Dipyridamole; D004280:Dobutamine; D025401:Echocardiography, Stress / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D016896:Treatment Outcome; D014665:Vasodilator Agents
chemical_list: D000889:Anti-Arrhythmia Agents; D002316:Cardiotonic Agents; D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; D004280:Dobutamine; D004176:Dipyridamole; D001285:Atropine; D017256:Technetium Tc 99m Sestamibi