Abstract 19056: Left Ventricle Longitudinal Strain was Reduced in Subclinical Patienst with Repaired Tof

Abstract

Background: Right ventricular (RV) dilation and dysfunction caused by residual pulmonary regurgitation afterh repaired tetralogy of Fallot (ToF) are associated with their prognosis. In contrast, left ventricular (LV) function has been focused as a novel determinant of prognosis in patients with repaired ToF. Although RV-LV interaction may be a cause of LV dysfunction, the reason of LV dysfunction in patients with repaired ToF was poorly understood. We aimed to assess LV regional myocardial function in consideration of interaction with RV properties.

Methods: We studied subclinical 27 patients with repaired ToF (11 male, 17.1 ± 4.9yrs) and 10 control subjects (7male, 13.9 ± 5.5yrs). RV and LV ejection fractions (EF) and end diastolic volume index (EDVi, ml/m2) were measured with 3-dimensional echocardiographic sysytem (Tomtec imaging systems). Pulmonary regurgitation(PR) fraction was caliculated by volumetric method [RV stroke volume - LV stroke volume / RV stroke volume]. Tricuspid annular plane systolic excursion (TAPSE) was measured in assessing RV systolic function.Left atrium area(LA), transmitral mitral flow ratio(MVE/A), and velocity ratio of early mitral flow to mitral ring (MV E/E’) were measured for evaluation of LV diastolic function. Global LV and RV longitudinal strain (LS) were assessed by speckle tracking echocardiography. Ramp protocol cardiopulmonary exercise testing was performed to measure peakVO2 (ml/kg/min).

Results: PR fraction (31±18%) was correlated with RVEDVi(r=0.532, p=0.001), however, not correlated with TAPSE, RVEF, and RV-LS. LV-LS was lower in patients with repaired ToF compared to control subjects (-29.1±5.7 vs -23.8±4.8 %, p=0.014). LV-LS was negatively correlated with PR fraction (r= -0.435, p=0.008), and RVEDV(r= -0.491,p=0.002). However, no correlation between RV-LS and LV-LS was observed. LV-LS was negatively associated with LA (r= -0.392, p=0.018), but not associated with MV E/A, MV E/E’ and peak VO2.

Conclusions: Even in subclinical patienst with repaired ToF, LV-LS was reduced as comoared to normal subjects. The longitudinal dysfunction may be rather affected by dilated RV, and clininical significance with LV diastolic function and exercise capacity were not clear in this setting.