Role of Oral Iron Treatment in the Management of Severe Dilated Cardiomyopathy in an 18-Month-Old Toddler: A Case Report

Introduction

Dilated cardiomyopathy (DCM), a myocardial disorder characterized by left ventricular (LV) dilatation and systolic dysfunction, is the most common cardiomyopathy in pediatric populations. Iron deficiency is the most prevalent nutrient deficiency around the globe and mainly affects children. The most common causes of iron deficiency in children include inadequate iron intake, malabsorption, abnormal red blood cells, and gastrointestinal losses related to excessive intake of cowʼs milk. Iron deficiency anemia has been implicated in the development of secondary cardiomyopathy [Higgins D et al. Am J Cardiol 2017; 120: 2049–2055, Mueller GC et al. Int J Pediatr 2012; 2012: 452909]. Iron is the most critical part of the cellular mechanism in cellular immunity, mitochondrial respiration, oxygen transport, and oxygen storage [Beard JL. J Nutr 2001; 131: 568S–579S; discussion 580S]. Herein, we would like to present the case of an 18-month-old toddler with severe iron deficiency anemia and cardiac dysfunction to highlight the critical repercussions of inadequate iron intake in childhood age.

Case Report

An 18-month-old toddler was admitted to our institutionʼs emergency department (ED) with complaints of pallor, malaise, and tachypnea. Past medical history was significant for rapid breathing and respiratory distress, which had been going on for three days and also had been complaining of fatigue and weakness for one week prior to the ED. Her weight was around 10 kg (between the 10th and 25th percentile for weight and height). Physical examination in the ED revealed tachypnea (40/minutes), tachycardia (heart rate of 140 beats per minute), and pitting edema of the lower extremities. The liver edge is palpable about 4 cm below the right costal margin. She had mild prolonged capillary refill time (3 seconds). His pulse oximetry was 95% on room air, blood pressure (90/50/75 mm Hg), and body temperature (36.4°C) were all normal. On pulmonary examination, thin crepitant crackles were detected in both lung lower lobes. A complete blood count revealed a WBC level of 12 000/mm³, a hemoglobin level of 6.2 g/dL, MCV 56.3 Fl, a hematocrit level of 18.1% and a platelet level of 580 000/mm³. The patientʼs C-reactive protein was 5 mg/dL. Renal and liver function tests were normal. Chest X-Ray demonstrated a bilateral infiltration in both lungs, and cardiomegaly was detected ([Fig. 1]). The patient had respiratory alkalosis (pH 7.6, pCO2: 30 mmHg, HCO3: 22 mmol/l ). Past medical history was significant for a loss of appetite for solid food that started almost a year ago, and the patient was drinking approximately 100 fluid ounces per day of cowʼs milk. The patient had not had any gastrointestinal blood loss prior to ED admission. The patient was transferred from the ED to the pediatric intensive care unit (PICU) due to deep anemia and respiratory failure.

Fig. 1 Chest X-Ray demonstrating a bilateral infiltration in both lungs, and cardiomegaly was detected.

On the 1^st day of PICU admission, a transthoracic echocardiographic examination (TTE) revealed signs of worsening dilated cardiomyopathy (DCM) (LVEDD 4.30 cm, z- score+5:35) with a dilated left atrium (LA) and a moderate LV systolic dysfunction (ejection fraction-EF: 33%, shorting fraction-SF: 18%) ([Fig. 2]). TTE also demonstrated moderate MR, mildaortic regurgitation, and slightly pulmonary hypertension. The patient’s coroner arteries’ origins were normal. The patient’s cardiac biomarkers were a high level of serum B-type natriuretic peptide of 10,312 pg/mL, a high-level CK MB of 41 ng/mL, and a normal level of Troponin I. A 12-lead ECG showed sinus rhythm with negativity in V5, and sinus tachycardia (155 beats per minute) was detected ([Fig. 3]). Intravenous diuretics and milrinone infusion were promptly initiated for the patient’s decompensated, low-output HF. Also, oral digoxin and Captopril were started for the patient’s heart failure. Blood tests were done for the etiology of anemia. The peripheral blood smear showed the presence of small, often hypochromic red blood cells (Microcytic hypochromic anemia). The patient also was found to have serum iron 10 μg/dL, TIBC 581 μg/dL, iron saturation 5%, and serum ferritin 2.1 ng/mL. MCV was 56.3 fL/cell, and RDW was 19.2%. Other laboratory tests, including white blood count, chemistry panel, lipid panel, urea, and creatinine, were within normal limits. The patient had diagnosed severe microcytic hypochromic anemia with iron deficiency. The patient was imposed with rapid blood transfusion for severe anemia. The patient was transfused with packed red blood cells over two days to a hemoglobin of 10 g/dL, and she was immediately started 6 mg/kg/day ferrous iron in two doses 1 hour before or 2 hours after meals to increase compliance. IV maintenance fluid and nasal oxygen were started to the patient. The serologic examination for Parvovirus B19 coxsackie and other viral etiology revealed was negative excluding some viral infection as etiology for dilated cardiomyopathy. However, since we did not perform a myocardial biopsy, we could not completely exclude viral etiology.

Fig. 2 A transthoracic echocardiographic examination revealing signs of worsening dilated cardiomyopathy with a dilated left atrium, a moderate left ventricular systolic dysfunction and second-degree mitral regurgitation.

Fig. 3 A 12-lead ECG showing sinus rhythm with negativity in V5, and sinus tachycardia.

On the 4^th day of PICU admission, the general condition of the patient and her respiration ameliorated rapidly after erythrocyte suspension, nasal oxygen, and inotropic support. The patient began to be monitored at room air. Blood tests done for the patient’s etiology of other anemia demonstrated a low level of folic acid of 2.5/gr, a low level of B12 of 100/gr, and a low level of 25-hydroxyvitamin D level of 2.2 ng/mL. Folic acid and vitamin C were added to the patient’s current treatment. The patient was started on vitamin C 100 mg 3 times daily for one week, followed by 100 mg daily, taking 600 IU of vitamin D daily, 1 mg intramuscular hydroxocobalamin (1,000 mcg) every day for one week was promptly initiated. The patient’s dilemma was consulted with the department of pediatric metabolism for further management. The patient’s plasma levels of total and free carnitine were within the normal range. Pompedisease was not detected, and other metabolic tests were normal. The patient’s hemoglobin levels increased to 10.5 gr/l after erythrocyte transfusion. In the meantime, her anti-tissue transglutaminase (anti-tTG) was negative for celiac disease. Genetic testing for genes implicated in DCM was negative for known pathologic variants.

On the 3^rd day of PICU admission, there was significant amelioration in the condition of the patient; thus, the milrinone treatment was discontinued. thus, the patient was transferred to a regular pediatric ward for further management. After being hospitalized in the pediatric ward for ten days, serial laboratory results showed signs of gradual amelioration of hemoglobin count (12.2 gr /dl) (ferritin 12 ng/mL, iron 10 mg/dL) and brain natriuretic peptide (500 pg/ml). An echocardiographic examination (the last echocardiographic examination before the patient was discharged) showed mildly left systolic dysfunction (EF: 50%, shorting fraction-SF: 25%).Thus, the patient was discharged from the hospital on the 20^th day of pediatric ward admission. The patient’s discharge diagnosis was cow’s milk-induced iron deficiency anemia with associated mildly-moderate cardiac dysfunction. The family was advised to decrease milk intake and continue iron supplementation at 6 mg/kg per day.

Publication History

Article published online:
30 August 2024