Case Report
A 4-year-old male with no significant past medical history presented to his pediatrician for a routine well-child visit and was noted to be in tachycardia at over 250 beats per minute. Further questioning revealed he had been experiencing some nausea and vomiting a few days prior to presentation but was otherwise asymptomatic. He was sent to the emergency room where an electrocardiogram (ECG) demonstrated a wide complex tachycardia at a rate of 270 bpm (Figure 1). He received three escalating doses of adenosine with no effect, followed by amiodarone (5mg/kg) intravenously with some rate but no rhythm control. He was then sedated and successfully cardioverted to a normal sinus rhythm. A chest radiograph showed a cardiac silhouette that appeared enlarged (Figure 2) and he was admitted for further management. Lab work was remarkable for a hemoglobin of 10.9 g/dL, brain natriuretic peptide (BNP) of 998 pg/mL, C reactive protein of 3.8 mg/dL, and a troponin of 0.21 ng/mL. The viral panel was positive for Epstein Barr Virus and Human Rhinovirus at presentation and was initially negative for the SARS CoV2 Rapid PCR test. A repeat PCR test 48 hours later, however, was positive for SARS CoV2. Echocardiogram images demonstrated a left ventricular (LV) mass along the free wall of the left ventricle extending to the apex and a small pericardial as well as a right pleural effusion. (Figure 3) The mass was further delineated on a cardiac magnetic resonance imaging scan that showed a 22x 52 mm mass with a distinct separation between the LV. The mass presumed to be a fibroma based on MRI characterization. (Figure 4)
He was started on 3 mg/kg/day of propranolol administered TID. He did not experience any further episodes of ventricular tachycardia and only had occasional premature ventricular contractions. Serial BNP and troponin labs began to normalize within 72 hours of admission. Considering the positive SARS CoV2 PCR test, cardiac surgery for mass excision was postponed. He was discharged home on a 30-day real-time, wireless cardiac event monitor that allowed for close monitoring while awaiting surgery.
Three weeks later he underwent a resection of the cardiac fibroma. The mass was intimately associated with the distal left anterior descending artery which was preserved and had limited septum involvement. He was transferred to the pediatric cardiovascular intensive care unit and had an uneventful recovery. A post-operative echocardiogram demonstrated normal biventricular function with no valve regurgitation and no residual mass or effusion. He was discharged home on post-operative day 5 after an uneventful postoperative course. The propranolol was eventually discontinued 3 months post-surgery as he continued to demonstrate no arrhythmias. The final pathology demonstrated a benign cardiac fibroma with intact borders.