LEFT VENTRICULAR VOLUME ASSESSMENT BY GEOMETRICAL MODELS IN PATIENTS OPERATED ON FOR TETRALOGY OF FALLOT

Objectives: MRI is proven to be an accurate method for noninvasive assessment of cardiac function in tetralogy of Fallot patients (TOF). Various geometrical models are used in healthy patients to quantify cardiac function. The purpose of this study is to assess the reproducibility and validity of these geometrical models in patients operated on for TOF by comparison with cMRI. Methods: This is a retrospective study of 59 patients with TOF (mean age 22.46 +/- 6.67). Left ventricular (LV) volumes and ejection fraction (EF) were quantified based on a 1.5 Tesla MRI. The LV volumes and EF were either assessed with modified Simpson rule (SR), hemisphere cylinder model (HC), single plane ellipsoid model (EM) and 4 chamber Simpson rule (4cSR). Results: Good correlations were found for all volumes and EF for SR mode compared with full volume data set (r(2) ranged between 0.63 and 0.82 with a p value <0.001 for all correlations). The HC, EM and 4cSR models proved to be less useful for the EF assessment (r(2) >0.53 for HC, r(2)0.1 and r(2)>0.41 for 4cSR respectively). Conclusion: Only SR model has proven to be a valuable method for the assessment of LV volumes, stroke volume and EF in TOF patients.