Liwei Hu1, Xiaodan Zhao2, Rongzhen Ouyang1, Shuang Leng2, WeiHui Xie1, Yafeng Peng1, Xiaofen Yao1, Yong Zhang3, Ru San Tan2,4, Liang Zhong2,4, and Yumin Zhong1
1Radiology, Shanghai Children's Medical Center, Shanghai, China, 2National Heart Centre Singapore, Singapore, Singapore, 3GE Healthcare, Shanghai, China, 4Duke-NUS Medical School, National University of Singapore, Singapore, Singapore
Synopsis
Right ventricular (RV) and atrial (RA)
dilation has been clinically observed in patients after initial repair of
tetralogy of Fallot (rTOF) and is associated with adverse long-term outcomes.
Due to RA and left atrial (LA) interaction, we aimed to determine the effect of
RA dilation on LA performance from feature tracking cardiovascular magnetic
resonance (CMR) in pediatric rTOF patients. Results revealed that LA strains
and strain rates were impaired in rTOF than age- and gender-matched healthy
volunteers. RA volumes are negatively associated with LA strains. These
findings may suggest LA diastolic dysfunction from chronic RV and RA dilations
in rTOF, even at early stage after initial repair.
Introduction
Right ventricular (RV) and atrial (RA)
dilation have been observed in conjunction pulmonary regurgitation developing
after repaired Tetralogy of Fallot (rTOF). Left ventricular (LV) and (LA) function
may be perturbed due to RV-LV and RA-LA interactions. Quantitation LA phasic reservoir,
conduit and contractile function has recently become feasible with cardiac
magnetic resonance (CMR) feature tracking (Leng et al 2018). We aimed to study
the relationship between LA performance and RA Volumes in pediatric rTOF
patients versus age- and gender-matched healthy volunteers.Methods
Pediatric rTOF patients (11±4 years) and
age- and sex-matched healthy controls (11±2 years) were prospectively recruited
between June 2017 - August 2019. Standard steady state free precession cine CMR
were acquired on 3T (Discovery MR 750, GE, USA) and 1.5 Tesla scanners
(Achieva, Philips Healthcare, Netherlands). Ventricular and atrial volumes and
ejection fractions were measured using CVI42 software (Circle Cardiovascular
Imaging, Calgary. Using CMR feature tracking software (CVI42), LA reservoir
(Ɛs), conduit (Ɛe) and booster strains (Ɛa) were determined at LV end-systole,
LV diastasis and pre-LA systole respectively. First derivatives of the
respective strains yielded corresponding peak strain rates. Statistical
analysis was performed using t test Mann-Whitney test for parametric and non-parametric
variables, respectively. Intra-observer and
inter-observer variability of LA strain and strain rate measurements were
determined from five randomly selected rTOF and five control subjects.Results
RV volumes, RA end-systolic volume (RAESV)
were increased, and RAEF decreased, in rTOF patients versus control (Tables 1
and 2). LA strains were significantly reduced in rTOF versus controls even as LA
EF were comparable (60±5% vs. 63±4%, P=0.06) (Table 3). LA reservoir strain
has good negative correlation with RA end-diastolic volume index (r=-0.51,
p<0.001) and RAESV index in rTOF group (r=-0.49, p=0.002). LA strains and strain rates have good reproducibility in Intra-observer and inter-observer analyses (Table
4).Conclusions
LA strains were reproducible
from feature tracking CMR in pediatric rTOF. The data showed abnormal LA
strain and strain rate in pediatric rTOF. These findings may suggest LA diastolic dysfunction from chronic RV and
RA dilations in rTOF, even at early stage after initial repair.Acknowledgements
No acknowledgement found.References
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