ECHOCARDIOGRAPHY ASSESSMENT OF SYSTOLIC FUNCTION IN DIFFERENT LEFT vENTRICULAR GEOMETRIES

Congenital heart diseases (CHD) appear as a large variety of anomalies with different ventricular shapes, sizes and haemodynamics . Reliable assessment of ventricular function in children with complex cHd, such as univentricular heart or after a Fontan operation, is difficult, as the majority of echocardiographic (ECHO) parameters rely on geometric assumptions or haemodynamic factors . A number of new echo methodologies, like Tissue Doppler Imaging (TDI), strain and strain rate have become available, allowing an assessment of different aspects of left ventricular (Lv) contraction . In particular, evaluation of Lv longitudinal systolic dynamics has progressively gained importance as a key aspect in the assessment of Lv systolic function . Longitudinal measures of wall function are: annular displacement and velocity, the displacement index, myocardial performance index (MPI), as well as mean strain/strain rate . Annular displacement, determined from M-mod, is a direct, early, sensitive, and easy-to-perform index of global Lv systolic function, but is age-dependent . TDI is a quantitative nongeometric measure of systolic and diastolic ventricular function . The most commonly used indices are mitral annular systolic peak S-wave velocity (S’) and MPI . The new parameter is displacement index (S’-wave velocity-time integral, divided by the end-diastolic distance from the mitral annulus to the Lv apex), very sensitive, not affected by age, heart rate, or BSA . Conclusions: Reliable assessment of systolic ventricular function in patients with complex CHD is possible through detailed study of Lv long-axis dynamics . Most importantly, new, specific tdi indices provide evidence of subtle cardiac dysfunction long before clinical or traditional ECHO signs are appreciable .