Early Intertwin Differences in Myocardial Performance During the Twin-to-Twin Transfusion Syndrome

Abstract

Background-In the twin-to-twin transfusion syndrome (TTTS), pressure rather than volume overload is increasingly considered as a key factor in the pathogenesis of the cardiomyopathy of the recipient twin. If this is the case, cardiac dysfunction should be among the first signs observed with TTTS. The objective of this study was to determine whether intertwin differences in myocardial function are modified early in the course of TTTS and whether they can help to differentiate this condition from intrauterine growth restriction (IUGR). Methods and Results-Eight variables were analyzed on the first fetal echocardiography on 21 pairs of twins with TTTS and 11 with IUGR. No difference was found between the 2 groups for the cardiothoracic ratio, pulsatility indices in the umbilical and middle cerebral arteries, and peak velocity of the middle cerebral artery. Significant difference was found for ventricular septal thickness, but with no association with the conditions under study. With TTTS, left ventricular shortening fraction was consistently greater in the donor twins, and myocardial performance indices (MPIs) were elevated in the recipient twins. This increase in MPI was caused by a lengthening of the isovolumic periods compared with those of the donor twin: left ventricular and right ventricular isovolumic periods 0.105Ϯ0.047 and 0.097Ϯ0.026 seconds, respectively, for the recipient twins versus 0.0561Ϯ0.46 and 0.065Ϯ0.03 seconds, respectively, for the donor twins (PϽ0.001). These changes in the isovolumic periods were mainly due to significant prolongation of isovolumic relaxation times. A change in left ventricular MPI Ն0.09 combined with a change in right ventricular MPI Ն0.05 would identify a TTTS with a sensitivity of 75% and a false-positive rate of 9%. Conclusions-The observed diastolic function impairment goes along with the pressure-overload pathogenic concept proposed in TTTS. Assessment of intertwin difference in MPI is a valuable tool for early differential diagnosis between TTTS and isolated IUGR.

Profiling fetal cardiac function in twin–twin transfusion syndrome

“…Although we have shown that the algorithm for staging the recipient's cardiomyopathy depicted in Figure 3 is not of prognostic value after laser coagulation, it outlines the importance of MPIs in the description of fetal cardiomyopathy along with their diagnostic value. Indeed, right and left ventricular performance indices were sufficient for an accurate classification of cardiac function across Profiles 1 to 3, confirming previous results addressing the value of cardiac function evaluation and particularly ventricular MPI as an early marker of TTTS in monochorionic twins 27,28 . This is further stressed by the lack of overlap between the cardiac profiles and the Quintero staging system, suggesting that at least part of the severity of the disease remains uncaptured by the latter 30 .…”

“…RV systolic function, diastolic function and MPI in both ventricles were impaired 21,22,27,28 . As reported in earlier studies 29 , UA-PI was raised in both donor and recipient twins, and DV abnormalities were more prevalent in the recipient than in the donor twin.…”

First-Trimester Fetal Cardiac Function

“…It can be used for early and differential diagnosis between twin-to-twin transfusion syndrome and intrauterine growth restriction because both have a similar initial presentation. Raboisson et al 13 found that the MPI increases in recipients twins because of a prolonged IVRT when compared with donor fetuses.…”

Blood pressures in newborns with twin–twin transfusion syndrome

“…The presence of fetal hypertension in the recipients is also supported by characteristic glomerular and vascular renal histopathological changes, 9 as well as cardiomyopathy and cardiac dysfunction classical of increased afterload resulting from increased peripheral vascular resistance and high vascular pressure. 26 Studies of newborn BP report a constant and sustained rise in BP values over the first hours to days after birth, for all infants, preterm or term, singletons or (non TTTS-) twins, including twins with weight discordance. [13][14][15]23,27 In contrast, the current data show a decrease in BP during the first 12 h of life in recipients.…”