Cardiac "fitness" training: an experimental comparative study of three methods of pulmonary artery banding for ventricular training.
BACKGROUND
When the left ventricle is unable to sustain a systemic pressure in transposition of the great arteries (TGA), left ventricular retraining is mandatory before the morphologic left ventricle under the aorta is switched. This is currently achieved by creating a ventricular overload through pulmonary artery banding, usually associated with an aortopulmonary shunt in case of a TGA with an intact ventricular septum. Our experimental study compared three different modes of increased ventricular afterload to obtain ventricular hypertrophy.


METHODS
Fifteen lambs (mean weight 48 kg) underwent pulmonary artery banding. Five animals (group I) received a classic band; 5 (group II) received a classic band which was adjusted at week 1 and 3; and 4 (group III) received a band which was tightened for 1 hour, twice a day (early morning and late afternoon). After 5 weeks, the lambs were evaluated hemodynamically before they were sacrificed and their hearts harvested for histologic examination.


RESULTS
No difference was noted in the hemodynamic data between groups 1 and II. Group III showed a greater ability to increase ventricular pressure in this model. No significant difference was noted between the three groups in terms of macroscopic alterations, but all animals demonstrated an increase in right ventricular wall thickness compared with control animals. Several fibrosis areas were evident in group I and II but none in group III.


CONCLUSIONS
Intermittent pulmonary artery banding is able to induce hemodynamically sufficient ventricular hypertrophy without fibrosis.
Le Bret
Emmanuel
E
Department of Cardiac Diseases, Institut Mutualiste Montsouris, Paris, France. emmanuel.lebret@imm.fr
Lupoglazoff
Jean Marc
JM
Borenstein
Nicolas
N
Fromont
Gaelle
G
Laborde
François
F
Bachet
Jean
J
Vouhé
Pascal
P
D000818:Animals; D001022:Aortic Valve Insufficiency / Q000209:etiology; D003250:Constriction; D005355:Fibrosis; D006346:Heart Septum / Q000473:pathology; D006352:Heart Ventricles / Q000503:physiopathology*; D006439:Hemodynamics; D018056:Hemorheology; D017379:Hypertrophy, Left Ventricular / Q000209:etiology; D008722:Methods; D009206:Myocardium / Q000473:pathology; D011300:Preoperative Care / Q000379:methods*; D011651:Pulmonary Artery; D012756:Sheep; D016037:Single-Blind Method; D014188:Transposition of Great Vessels / Q000601:surgery*