title: Pressure response in Chagasic cardiomyopathy patients after using Sildenafil.
abstract: OBJECTIVE
  To accurately verify the effect of Sildenafil on blood pressure (BP) and heart rate (HR) in individuals with Chagasic myocardiopathy (CMC) and severe systolic ventricular dysfunction (EF<40%) submitted to physical activity.
  
  
  METHODS
  Twelve men with ejection fractions <40% and CMC confirmed by a serological test were assessed. The six-minute walk test (6MWT) was performed before and after administration of 50 mg of Sildenafil, with a 30 minute interval. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure were taken and compared before and after each 6MWT. For statistical analysis purposes, the study was divided into four stages: before the 6MWT and administration of Sildenafil (S1); after the 6MWT but before the administration of Sildenafil (S2); after the administration of Sildenafil but before the 6MWT (S3); and after the administration of Sildenafil and the 6MWT (S4).
  
  
  RESULTS
  Participant ages ranged from 47 to 68 years (57.6 +/- 6.4). SBP and DBP after the 6MWT and the administration of Sildenafil (S4) were lower than before taking the drug (S2): 134.2 +/- 15.1 versus 125.5 +/- 14.0 and 88.4 +/- 12.4 versus 83.0 +/- 10.8, respectively. None of the patients reported any symptoms during the 6MWT. There were no differences in the distances walked during the 6MWT before or after taking Sildenafil (487.5+/-15.22 versus 505.3+/-18.45 meters, respectively)-p=0.056, or in HR (before Sildenafil 75.5 +/- 8.79 and 96.8 +/- 10.36 bpm and after 77.1 +/- 9.81 and 96.1 +/- 12.97 bpm).
  
  
  CONCLUSIONS
  A significant reduction in BP after physical activity while using Sildenafil was observed. However, during the six-minute walk test, the patients did not report any symptoms, indicating that this effect is not sufficient to cause clinical manifestations in CMC and heart failure patients.
authors.affiliation: Universidade Federal da Bahia, Salvador, BA, Brazil. rathanazio@yahoo.com.br
authors.forename: Rodrigo Abensur
authors.initials: RA
authors.lastname: Athanazio
authors.forename: Daniel Meira
authors.initials: DM
authors.lastname: Freitas
authors.forename: Daniela Batista
authors.initials: DB
authors.lastname: de Almeida
authors.forename: Nei
authors.initials: N
authors.lastname: Dantas
authors.forename: Francisco
authors.initials: F
authors.lastname: Reis
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D002598:Chagas Cardiomyopathy / Q000188:drug therapy* / Q000503:physiopathology; D016009:Chi-Square Distribution; D005080:Exercise Test / Q000379:methods; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D011687:Purines / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000627:therapeutic use*; D013599:Systole; D013997:Time Factors; D014665:Vasodilator Agents / Q000627:therapeutic use*; D018754:Ventricular Dysfunction / Q000188:drug therapy
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate