Fetal left‐atrial posterior‐space‐to‐diagonal ratio at 17–37 weeks' gestation for prediction of total anomalous pulmonary venous connection

Abstract

The left-atrial posterior-space-to-diagonal (LAPSD) ratio and post-left atrium space (PLAS) index are significantly higher in cases of total anomalous pulmonary venous connection (TAPVC) than in fetuses with a normal heart, independent of whether fetal TAPVC is isolated or associated with complex additional cardiac lesions. In normal fetuses, the LAPSD ratio and PLAS index demonstrate a minimal decrease during gestation and can be considered age-independent parameters. Both indices are independent of fetal gender, four-chamber view type (apical, basal or lateral), TAPVC type and presence of additional cardiac anomalies. What are the clinical implications of this work?The cut-offs of ≥ 0.35 for the LAPSD ratio and ≥ 1 for the PLAS index demonstrated similar excellent diagnostic performance for detecting fetal TAPVC, with a sensitivity of 100% and specificity of around 96%. The LAPSD ratio represents a novel sensitive diagnostic predictor that can be used to improve the prenatal detection of TAPVC in the same way as does the PLAS index.

Prenatal Ultrasound Markers of Isolated Total Anomalous Pulmonary Venous Return and a Sequential Approach to Reach Diagnosis

“…[ 13 ] Other studies have confirmed its reliability in differentiating TAPVR from normal cases, showing low inter- and intraobserver variabilities. [ 10 12 ] Notably, the post-LA space index was independent of the gestational age,[ 13 ] the four-chamber view orientation (apical, basal, or lateral), and the TAPVR type. [ 12 ] Studies have demonstrated that post-LA space index cutoff value of ≥1.27 or 1 exhibited excellent diagnostic performance with a sensitivity of 100% and specificity of 99% and 95.1%, respectively.…”

“…[ 12 ] Studies have demonstrated that post-LA space index cutoff value of ≥1.27 or 1 exhibited excellent diagnostic performance with a sensitivity of 100% and specificity of 99% and 95.1%, respectively. [ 10 12 ]…”

“…An alternative marker with a similar diagnostic performance and independence of the gestational age was recently proposed by Anuwutnavin et al . [ 12 ] The new method also focuses on the enlarged area behind the LA: the “left-atrial posterior-space-to-diagonal (LAPSD) ratio,” which is calculated by dividing the LA-DAo distance by the left atrial diameter [ Figure 2 b]. The authors hypothesized that a higher LAPSD ratio reflects the enlargement of the retroatrial space and smaller LA, which are considered typical changes for TAPVR.…”

“…LAPSD ratio ≥ 0.35 was proposed as an optimal cutoff for detecting TAPVR. [ 12 ] The authors underlined that in certain cases, it might be crucial to employ multiple indirect signs to ensure the correct diagnosis, for example, in patients with a small LA such as hypoplastic left heart syndrome.…”

The Holy Grail of obstetric ultrasound: can artificial intelligence detect hard‐to‐identify fetal cardiac anomalies?

“…Today, in experienced hands, most major CHDs can be detected in the second trimester 3 and approximately two-thirds of major CHDs can be diagnosed before 14 weeks of gestation 4,5 . Yet, even in an era in which exome sequencing is feasible 6 , CHD diagnosis remains suboptimal, owing in large part to the complexity of cardiac anatomy and function, and the inherent difficulty of ultrasound examination of the fetal heart 7,8 . Accordingly, in countries in which a national screening program for CHD exists, on average only 50% of major CHD is recognized during pregnancy 9 .…”