Intermittent systolic overload promotes better myocardial performance in adult animals.
BACKGROUND
Corrected transposition of great arteries often evolves with right ventricular dysfunction. The ventricular preparation for anatomic correction in adult patients has produced disappointing results.


OBJECTIVE
To assess right ventricular hypertrophy (RV) induced by conventional and intermittent pulmonary banding (PB) in adult animals.


METHODS
Nineteen adult goats were divided into three groups: conventional (six animals), intermittent (six animals) and control (seven animals). The Conventional group underwent fixed PB with cardiac tape, while the intermittent group received PB adjustable device, which generated systolic overload for 12 hours, alternated with 12 hours of rest of RV. The pressures of the RV, pulmonary artery and aorta were measured throughout the study. Echocardiography was performed weekly. After four weeks, the animals were euthanized for morphological evaluation of the ventricles. The Control group was put to euthanasia for analysis at baseline.


RESULTS
Pressure overload was lower in the intermittent group (p = 0.001), compared to the conventional group. There was an increase in the thickness of the RV of the Intermittent group measured by echocardiography compared to their baseline values (p < 0.05). The myocardial performance index in the RV group was better in the Intermittent group (p = 0.024), compared to the Conventional group. The groups stimulated showed increased muscle mass compared to the Control group (p = 0.001). There was no difference in myocardial water content.


CONCLUSIONS
The intermittent BP developed hypertrophy of better performance, suggesting this protocol as the preferred method of ventricular preparation.
Miana
Leonardo Augusto
LA
Instituto do Coração, Universidade de São Paulo, SP, Brazil. leonardomiana@cardiol.br
Assad
Renato S
RS
Abduch
Maria C D
MC
Gomes
Guilherme Seva
GS
Nogueira
Ananda Rigo
AR
Oliveira
Fernanda Santos
FS
Telles
Bruna Lopes
BL
Souto
Maria Teresa
MT
Silva
Gustavo J
GJ
Stolf
Noedir A G
NA
D000818:Animals; D003250:Constriction; D005260:Female; D006041:Goats; D006439:Hemodynamics / Q000502:physiology*; D017380:Hypertrophy, Right Ventricular / Q000473:pathology* / Q000503:physiopathology; D023421:Models, Animal; D011300:Preoperative Care / Q000379:methods; D011651:Pulmonary Artery / Q000503:physiopathology*; D011897:Random Allocation; D013599:Systole / Q000502:physiology; D014188:Transposition of Great Vessels / Q000601:surgery