Right ventricular speckle tracking echocardiography: A new tool for decision-making after surgical repair of tetralogy of Fallot?

Abstract

Surgical correction of tetralogy of Fallot (TOF) has evolved in recent years from correction after childhood to early surgery, even in the neonatal period. Before and after correction the right ventricle is mainly affected, experiencing persistent pressure and/or volume overload and intrinsic or acquired right ventricular (RV) myopathy. On follow-up, these patients can present RV enlargement, dysfunction and fibrosis, all with significant clinical impact, such as exercise limitation, RV failure and a substrate for lethal ventricular arrhythmias and sudden cardiac death (SCD).1 A combination of varying degrees of long-standing pulmonary regurgitation and residual stenosis has been identified as a major issue after TOF correction that over time triggers RV remodeling, affecting ventricular synchrony and coupling and also impairing left ventricular function. 2In long-term follow-up, arrhythmias are a common problem in more than 30% of patients with repaired TOF, sometimes causing adverse outcomes and even SCD, which has an estimated incidence of 0.2% per year in these DOI patients. There is thus a need for accurate risk predictors in the follow-up of TOF patients. 3 Various clinical factors have been investigated as predictors of late arrhythmic events, but they still lack strong positive predictive accuracy. This situation has prompted considerable changes in the surgical approach to TOF in recent decades. The current approach favors repair at a younger age (<2 years), efforts to preserve pulmonary valve competence and to avoid ventriculotomy, and extensive removal of infundibular muscle.4 Nevertheless, definitive evidence on the optimal surgical strategies to protect RV function and reduce arrhythmias and risk of SCD is lacking. 5One of the hot topics in TOF is active long-term preservation of RV function. Ways to prevent significant pulmonary regurgitation and to avoid RV dilatation remain the main target, but the optimal timing for therapeutic intervention remains uncertain, although there is a trend towards early reintervention and acceptance of certain approaches is emerging. 6,7 Careful imaging surveillance of RV size and function is essential to determine optimal timing of additional corrective interventions.7 Which imaging parameters are the most reliable for decision-making in clinical assessment remains a crucial question.Although there have been many advances in noninvasive RV imaging during the past decade, echocardiography http://dx.doi.org/10.1016/j.repc.2016.11.001 0870-2551/© 2016 Published by Elsevier España, S.L.U. on behalf of Sociedade Portuguesa de Cardiologia. Documento descargado de http://www.elsevier.pt el 09/01/2017. Copia para uso personal, se prohíbe la transmisión de este documento por cualquier medio o formato.