Abnormal left ventricular rotation and twist in adult patients with corrected tetralogy of Fallot

Abstract

Left ventricular (LV) dysfunction is a major determinant of late adverse clinical outcome in adult patients with tetralogy of Fallot (ToF). Therefore, early detection is important. Speckle-tracking echocardiography (STE) has emerged as a quantitative technique to assess LV function. The aim of this study was to evaluate LV rotation and twist with STE in adult ToF patients and their association with right ventricular (RV) and LV dimensions and function, exercise capacity, and NT-proBNP level. Eighty-two ToF patients and 56 healthy controls matched for age and gender underwent echocardiography, electrocardiography, cardiac magnetic resonance imaging (CMR), bicycle ergometry, and NT-proBNP measurement. For STE, short-axis parasternal views were obtained at the LV base and apex. We analysed LV apical and basal rotation curves and calculated LV twist. Of the 82 ToF patients (55% male, age 33 ± 10 years, 98% NYHA I), 58 (71%) had normal twist, but lower than the controls [12.5 (IQR: 6.6) vs. 16.9 (IQR: 8.2) degrees, P = 0.002] mainly due to decreased apical rotation. Twenty-one (26%) patients had abnormal apical rotation which was associated with larger LV dimensions and decreased systolic biventricular function. Multivariable regression analyses showed positive relations of LV twist with biventricular systolic function measured with echocardiography as well as CMR. The majority of adults with corrected ToF show a reduced LV twist. Strikingly, one-quarter of these patients have an abnormal apical rotation which is associated with decreased systolic LV and RV function. These findings suggest that abnormal apical rotation is a new objective diagnostic criterion for detection of ventricular dysfunction.