Right Ventricular Inefficiency in Repaired Tetralogy of Fallot: Proof of Concept for Energy Calculations From Cardiac MRI Data
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Repaired tetralogy of Fallot (rTOF) patients develop right ventricular (RV) dilatation and dysfunction. To prevent their demise, pulmonary valve replacement is necessary, though appropriate timing for it is challenged by a paucity of reliable diagnostic parameters. In this pilot study, we hypothesized that stroke work (SW) and energy calculations would delineate the inefficiency of RV performance in rTOF. RV SW was calculated for both an rTOF and a normal subject by utilizing RV pressure and volume measurements obtained during cardiac catheterization and MRI studies. Energy transfer rate and ratio were computed at the main pulmonary artery (PA). Compared to the normal RV, the rTOF RV had higher operating pressure, lower computed SW (0.078 J vs. 0.115 J for normal), and higher negative energy transfer at the PA (0.044 J vs. 0.002 J for normal). Furthermore, the energy transfer ratio was nearly twice as high for the normal RV (1.06) as for the rTOF RV (0.56). RV SW and energy transfer ratio delineate important operational efficiency differences in blood flow from the RV to the PA between rTOF and normal subjects. Our pilot data suggest that the rTOF RV is significantly less efficient than normal.
KeywordsRight ventricular stroke work Tetralogy of Fallot Pulmonary insufficiency Phase contrast MRI
- 25.Morbiducci, U., R. Ponzini, G. Rizzo, M. Cadioli, A. Esposito, F. De Cobelli, A. Del Maschio, F. M. Montevecchi, and A. Redaelli. In vivo quantification of helical blood flow in human aorta by time-resolved three-dimensional cine phase contrast magnetic resonance imaging. Ann. Biomed. Eng. 37:516–531, 2009.CrossRefPubMedGoogle Scholar
- 36.Sundareswaran, K. S., K. R. Kanter, H. D. Kitajima, R. Krishnankutty, J. F. Sabatier, W. J. Parks, S. Sharma, A. P. Yoganathan, and M. Fogel. Impaired power output and cardiac index with hypoplastic left heart syndrome: a magnetic resonance imaging study. Ann. Thorac. Surg. 82:1267–1275, 2006; (discussion 1275–1267).CrossRefPubMedGoogle Scholar