title: Reversible pulmonary trunk banding VIII: Intermittent overload causes harmless hypertrophy in adult goat.
abstract: BACKGROUND
  Traditional pulmonary artery banding (PAB) is not always suitable for mature subpulmonary ventricle retraining. We sought to assess in detail the myocardial morphologic adaptations of two different protocols for inducing right ventricular (RV) hypertrophy in an adult animal model.
  
  
  METHODS
  Eighteen adult goats were distributed into three groups: sham (no systolic overload), traditional (continuous systolic overload), and intermittent (daily 12-hour systolic overload). Systolic overload was adjusted to achieve a 0.7 RV-to-aortic pressure ratio. All animals underwent weekly echocardiographic studies, and hemodynamic evaluations were performed 3 times a week. After 4 weeks, the animals were humanely killed for morphologic assessment.
  
  
  RESULTS
  A 37.2% increase was observed in the RV wall thickness of the intermittent group (p<0.05), but no significant echocardiographic changes were observed in the other two groups. The intermittent and traditional groups had a 55.7% and 36.7% increase in RV mass, respectively, compared with the sham group (p<0.05). No differences were observed in myocardial water content of the three groups (p=0.27). RV myocardial fiber and nuclei diameters were increased in the intermittent group compared with the sham group (p<0.05). The area of collagen deposition in the RV interstitium was increased 98% in traditional group compared with the sham group (p<0.05). No significant cellular proliferation occurred in any group.
  
  
  CONCLUSIONS
  This study suggests that a more effective and harmless hypertrophy can be achieved in adult animals using intermittent PAB compared with the traditional approach.
authors: Laboratory of Cardiovascular Surgery Research, LIM-11, Heart Institute, University of São Paulo School of Medicine, São Paulo, Brazil. leonardomiana@sbccv.org.br
authors: Leonardo A
authors: LA
authors: Miana
authors: Renato S
authors: RS
authors: Assad
authors: Maria C D
authors: MC
authors: Abduch
authors: Gustavo J J
authors: GJ
authors: Silva
authors: Ananda R
authors: AR
authors: Nogueira
authors: Vera D
authors: VD
authors: Aiello
authors: Luiz Felipe P
authors: LF
authors: Moreira
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004452:Echocardiography; D006041:Goats; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017380:Hypertrophy, Right Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D008026:Ligation; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D016278:Ventricular Function, Right / Q000502:physiology*; D017725:Ventricular Pressure; D020257:Ventricular Remodeling / Q000502:physiology*