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©The Author(s) 2026. Published by Baishideng Publishing Group Inc. All rights reserved.
Preterm heart failure and refractory lactic acidosis caused by congenital hypothyroidism: A case report and review of literature
Hong-Ju Chen, Jiao Li, Xiao-Ming Xu, Bo Zhang, Bo-Chao Cheng, Jing Shi
Hong-Ju Chen, Jiao Li, Xiao-Ming Xu, Jing Shi, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Hong-Ju Chen, Jiao Li, Xiao-Ming Xu, Jing Shi, Key Laboratory of Birth Defects and Related Diseases of Women and Children (West China Second University Hospital, Sichuan University), Ministry of Education, Chengdu 610041, Sichuan Province, China
Hong-Ju Chen, Xizang Region Child Development Clinical Medical Research Center, Women and Children’s Hospital of Xizang Autonomous Region, Lhasa 850000, Xizang Autonomous Region, China
Bo Zhang, Department of Ultrasound, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Bo-Chao Cheng, Department of Radiology, West China Second University Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Chen HJ undertook the data analysis and interpretation; Chen HJ, Li J, Xu XM, Zhang B, and Cheng BC involved in the drafting of the manuscript; Li J, Xu XM, Zhang B, Cheng BC, and Shi J reviewed the manuscript; Zhang B and Cheng BC assisted in collecting data; Shi J conceptualized and designed the study. All authors have read and approved the final manuscript.
Supported by Xizang Autonomous Region Science and Technology Program, No. XZ202501JD0017; Clinical Research Funding of West China Second University Hospital, Sichuan University, No. KL075; National Natural Science Foundation of China, No. 81501304; and Sichuan Science and Technology Program, No. 22ZDYF0831.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Jing Shi, PhD, Department of Pediatrics, West China Second University Hospital, Sichuan University, No. 20 Section 3, Renmin South Road, Wuhou District, Chengdu 610041, Sichuan Province, China.
shijing@scu.edu.cn
Received: November 7, 2025
Revised: December 1, 2025
Accepted: December 22, 2025
Published online: January 6, 2026
Processing time: 59 Days and 15.6 Hours
BACKGROUND
Congenital hypothyroidism (CH) is a common condition in both preterm and term infants characterized by either thyroid gland absence or hypofunctionality. The clinical association of refractory lactic acidosis and heart failure has rarely been observed in cases of pediatric patients with CH pathology. Here, we explored the etiological relationship between CH, heart failure, and refractory lactic acidosis to reflect the importance of thyroid function screening in neonates with heart disease.
CASE SUMMARY
A 33-day-old extremely premature female infant presented with tachypnea, respiratory distress, recurrent infections, and abdominal distension postnatal. On admission to our facility, she had cardiomegaly, hepatomegaly, and lactic acidosis (revealed on blood gas analysis), with lactate progressively rising to 25 mmol/L. Chest radiographs showed pulmonary congestion, while echocardiography revealed cardiac enlargement, left ventricular wall thickening, and pericardial effusion. Initial management aimed at correcting acidosis and treating heart failure proved ineffective. After reassessment, thyroid function tests showed significantly decreased triiodothyronine, free triiodothyronine, thyroxine, and free thyroxine levels, with a significantly increased thyroid-stimulating hormone level, confirming a CH diagnosis. Levothyroxine was administered, resulting in rapid correction of lactic acidosis and gradual improvement of thyroid function and systemic symptoms, culminating in full recovery and discharge. We also reviewed the relevant literature on thyroid and cardiac dysfunctions in order to explore their deeper association.
CONCLUSION
This case links CH-induced heart failure with refractory lactic acidosis, urging prompt thyroid screening in affected neonates to reduce mortality.
Core Tip: This report details a critical case of congenital hypothyroidism in a preterm infant, presenting as severe heart failure and refractory lactic acidosis. The infant showed a rapid, life-saving response to levothyroxine, highlighting congenital hypothyroidism’s role as a reversible cause of cardiovascular collapse. A key novelty is the profound lactic acidosis, a rarely reported feature of neonatal hypothyroidism. This case underscores the need for high clinical suspicion and repeat screening in preterm infants with unexplained heart failure or metabolic acidosis. Our findings advance understanding of thyroid hormones’ role in cardiac metabolism and confirm that prompt treatment is vital for excellent outcomes.
