Hypokinetic Hypertrophic Cardiomyopathy: A Rare Case Of A Spontaneously Regressive Form In A Newborn
Lamouri, I., Ech-Chebab, M., Ayyad, A., Messaoudi, S., Babakhouya, A., & Amrani, R. (2024). Hypokinetic Hypertrophic Cardiomyopathy: A Rare Case of a Spontaneously Regressive Form in a Newborn. Cureus, 16(7), e64186. https://doi.org/10.7759/cureus.64186
View Original Source →Abstract
Hypertrophic cardiomyopathy (HCM) of the newborn is a rare condition, characterized by great clinical variability, with a relative paucity of data on the pediatric population, especially newborns. Early diagnosis can have an impact on the patient's life course and prevent progression to sudden death. In this article, we report the case of a newborn admitted with late-onset neonatal respiratory distress, complicated by heart failure. The newborn was matured by two antenatal injections of betamethasone, which were received as part of a threat of premature delivery. Echocardiography revealed hypokinetic HCM. The rapidity of the establishment of the diagnosis contributed to the patient's survival and improvement within a few weeks under well-managed medical treatment. A complete workup was conducted, with negative results. The most suggested explanation for this condition was the use of antenatal corticosteroids.
Case Details
Disease Location
Heart
Personal Characteristics
Seventeen-day-old female. History of vulvovaginitis during pregnancy, with the onset of threatened preterm labor at 33 weeks, for which the mother received two intramuscular injections of betamethasone 12 mg, repeated at a 24-hour interval.
Clinical Characteristics
The mother reported noticing fatigue in her newborn during breastfeeding since birth. The newborn was hospitalized for neonatal respiratory distress with feeding refusal. Clinical examination revealed a slightly pale, tonic, responsive, afebrile newborn with a weak sucking reflex and primitive reflexes. She was tachycardic at 186 beats per minute with a capillary refill time of less than three seconds. Abdominal examination revealed hepatomegaly with a liver span of 6 cm. Chest x-ray showed cardiomegaly with a cardiothoracic ratio of 0.65 and convexity of the left lower arch. Echocardiography showed left ventricular hypertrophy, predominantly septal, with a thickened posterior wall measuring 6 mm, hypokinetic with an ejection fraction of 43%. Pro-bnp was elevated. Furosemide at a dose of 2 mg/kg/day with potassium supplementation was started. She was diagnosed with hypokinetic hypertrophic cardiomyopathy in response to prenatal betamethasone exposure.
Remission Characteristics
Three days after starting treatment, the newborn became normocardic at 135 beats per minute, hepatomegaly decreased over time, and the baby regained autonomy in feeding and breathing. Follow-up echocardiogram performed 15 days later showed an improvement in ejection fraction to 66% and a reduction in posterior wall thickness to 4 mm. Echocardiography was repeated at three months and showed normalization.
Treatment & Mechanisms
Clinical Treatment
Prenatal corticosteroid furosemide potassium supplement