Transthoracic Echocardiography in Children and Young Adults with Congenital Heart Disease
Figure 1
Assessment of right ventricular (RV) function by echocardiography. (a) %FAC, calculated from measures from the apical four-chamber view. The importance of longitudinal shortening can be appreciated in this image. (b) MPi, calculated by measuring the ejection time on the pulmonary artery tracing and the time between closure and opening of the tricuspid valve on the tricuspid inflow tracing. MPi = (TCOT-eT)/eT, MPi was normal after tetralogy of Fallot repair in this patient. (c) TAPSE. An M-mode echocardiogram through the tricuspid annulus is obtained, and the excursion of the tricuspid annulus is measured as illustrated. This index enables assessment of longitudinal RV function. (d) Tissue Doppler velocities of the tricuspid annulus. Pulsed tissue Doppler measurements can be used to calculate tissue velocities. Systolic velocities can be used as a parameter for systolic longitudinal RV function. (e) Longitudinal strain measurements of the right ventricle, made using speckle tracking technology. By convention, systolic longitudinal shortening is represented as a negative value and can be measured in six different segments. The mean values of these segments are used to trace a mean longitudinal strain curve (white dotted line). The value at end-systole is then measured. (f) Color tissue Doppler echocardiogram at the lateral tricuspid valve annulus and measurement of iVA. Aortic valve opening and closure are depicted by green lines for event timing. The timing of these events may be taken as that of pulmonary valve opening and closure. The slope of iVA is shown. Note that iVA occurs within the QRS complex and peaks before pulmonary valve opening in the isovolumic period. A′: late diastolic tissue velocity; AVC: aortic valve closure; AVO: aortic valve opening; e′: early-diastolic tissue velocity; eT: ejection time; %FAC: percentage fractional area change; IVA: isovolumic acceleration; MPI: myocardial performance index; S′: systolic tissue velocity; TAPSE: tricuspid annular systolic plane excursion; TCOT: tricuspid valve closure-opening time. Copyright from Mertens et al., Nat. Rev. Cardiol 2010 (doi:10.1038/nrccardio.2010.118) with permission from the publisher, Macmillan Publishers Limited, Copyright approval from Nature Publishing Group.
