Impaired regional left ventricular strain after repair of tetralogy of Fallot.

Purpose: To test the potential of magnetic resonance imaging (MRI) in early detection of left ventricular (LV) dysfunction in patients with pulmonary regurgitation and normal LV ejection fraction after repair of tetralogy of Fallot. Materials and Methods: Patients (n = 18) with repaired tetralogy of Fallot and pulmonary regurgitation were prospectively recruited. Healthy volunteers (n = 10) were used as control. Tagging MR images were acquired at the base, mid, and apical LV levels for assessing segmental rotation and circumferential strain. Cine MR images and velocity- encoded MR images were also acquired for assessment of biventricular volumes and biventricular function and pulmonary regurgitant fraction, respectively. Mean values were compared between groups using unpaired Student's t- test. Results: Patients presented with preserved global LV function (LVEF of 59 +/- 5%). A significant decrease in LV peak circumferential strain was seen in patients compared with normal volunteers at the basilar (-15.6 +/- 4.5% vs. -17.6 +/- 4.4%; P < 0.01) and apical (-14.46 +/- 6.1% vs. -17.3 +/- 5.1%, P < 0.01) slices. LV peak rotation was also delayed in patients compared with volunteers at the basilar (6.1 +/- 2.6 degrees vs. 4.2 +/- 0.6 degrees; P < 0.01) and mid (8.0 +/- 1.7 degrees vs. 4.9 +/- 1.0 degrees; P < 0.01) slices. Conclusion: MRI can detect early regional LV dysfunction in patients with preserved LVEF after repair of tetralogy of Fallot. MR may be a useful technique for guiding clinical decisions in these patients in order to prevent future global LV deterioration. (Less)