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.