Jean Bennett, MD
Pediatrician
David Grant USAF Medical Center
Fairfield, California
Disclosure information not submitted.
Rachel Bridwell, MD
MD
Brooke Army Medical Center, United States
Disclosure information not submitted.
Candace Percival, MD
MD
Brooke Army Medical Center, United States
Disclosure information not submitted.
Elumalai Appachi, MD
MD
Baylor College of Medicine at the Children's Hospital of San Antonio, United States
Disclosure information not submitted.
Monesha Gupta, MD
MD
Baylor College of Medicine at the Children's Hospital of San Antonio, United States
Disclosure information not submitted.
Mohammed Salameh, MD
Assistant Professor
Childrens Hospital of San Antonio
San Antonio, Texas
Disclosure information not submitted.
Title: Myxedema Heart Disease in a Teenage Child
Introduction: Myxedema heart disease is an exceptionally rare condition with few reported cases in adults. Due to the paucity of reported cases in children, managing those patients can be especially challenging.
Description: A 12-year-old female presented in severe congestive heart failure secondary to myxedema heart disease complicated by preexisting valvular heart disease. The patient was admitted to the pediatric intensive care unit and medical management included inotropic and vasopressor support, non-invasive positive pressure ventilation, and judicious diuresis. An echocardiogram showed severe biventricular dysfunction with decreased ejection fraction and severe valvular disease. She was started on levothyroxine and liothyronine, adjusted based on her dynamic thyroid function studies. During the patient’s hospitalization, the thyroxine level normalized and, although her TSH trended towards normal, two months into inpatient management, despite persistently normal T4 levels, the TSH continued to remain elevated. Likewise, her cardiac ventricular function improved, but did not return to baseline, and she was discharged with the expectation of the need for months of close monitoring until her heart function fully recovered.
Discussion: Myxedema heart is seen in hypothyroid patients who develop cardiomegaly, left ventricular systolic dysfunction, and ECG changes to include low voltage, sinus bradycardia, non-specific ST-T wave changes, and junctional rhythm. Histological evaluation reveals mucinous vacuolization, intercellular and intracellular thickening and edema with progression to irreversible fibrotic changes to the myocardium and vasculature. These structural changes cause valvular dysfunction, left ventricular hypertrophy, impaired systolic, and left ventricular function. The principles of management include managing heart failure and thyroid replacement. Levothyroxine, used in the treatment of hypothyroidism, has a seven-day half-life; therefore, to avoid continued complications or a risk for myxedema coma, liothyronine can be used, given its rapid onset within 24 hours. Medications should be given intravenously due to the possibility of decreased absorption. This is the first reported pediatric case diagnosed with myxedema heart disease and highlights the management strategy necessary in similar cases.