King's College London

Research portal

Fetal Speckle-Tracking: Impact of Angle of Insonation and Frame Rate on Global Longitudinal Strain

Research output: Contribution to journalArticle

Janina Semmler, Thomas G. Day, Georgios Georgiopoulos, Coral Garcia-Gonzalez, Jesica Aguilera, Trisha V. Vigneswaran, Vita Zidere, Owen I. Miller, Gurleen Sharland, Marietta Charakida, John M. Simpson

Original languageEnglish
Pages (from-to)1141-1146.e2
JournalJournal of The American Society of Echocardiography
Volume33
Issue number9
DOIs
Publication statusPublished - Sep 2020

King's Authors

Abstract

Background: There is a growing body of research on fetal speckle-tracking echocardiography because it is considered to be an angle-independent modality. The primary aim of this study was to investigate whether angle of insonation and acquisition frame rate (FR) influence left ventricular endocardial global longitudinal peak strain (GLS) in the fetus. Methods: Four-chamber views of 122 healthy fetuses were studied at three different angles of insonation (apex up/down, apex oblique, and apex perpendicular) at high and low acoustic FRs. GLS was calculated, and a linear mixed-model analysis was used for analysis. Six hundred fifty-six fetal echocardiographic clips were analyzed (288 in the second trimester, at a median gestation of 21 weeks [interquartile range (IQR), 1 week], and 368 in the third trimester, at a median gestation of 36 weeks [IQR, 2 weeks]). Results: Angle of insonation and FRs were significant determinants of GLS. Ventricular septum perpendicular to the ultrasound beam was associated with higher (more negative) GLS compared with apex up/down (at high FR: −21.8% vs −19.7%, P < .001; at low FR: −24.1% vs −21.4%, P < .001). Higher frames per second (FPS; median 149 FPS [IQR, 33 FPS] = 61 frames per cycle [FPC] [IQR, 17 FPC]) compared with lower FPS (median 51 FPS [IQR, 15 FPS] = 22 FPC [IQR, 7 FPC]) at the same insonation angle resulted in lower GLS (apex up/down: −19.7% vs −21.4%, P < .001; apex oblique: −21.2% vs −22.7%, P < .001; apex perpendicular: −21.8% vs −24.1%, P < .001). Conclusions: The present findings show that insonation angle and FR influence GLS significantly. These factors need to be considered when comparing studies with different acquisition protocols, when establishing normative values, and when interpreting pathology. Speckle-tracking echocardiography cannot be considered an angle-independent modality during fetal life.

View graph of relations

© 2018 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454