High efficacy of low-dose flecainide as add-on therapy to beta-blocker for the treatment of high burden of idiopathic ventricular arrhythmias in a juvenile athlete: a case report

Georgios A Christou ^1* Konstantinos Letsas ² Maria Konstandi ¹ Maria Christou ¹ Konstantinos A Christou ¹ Chris Kyriakopoulos ¹ Eleftherios Vidalakis ³ Stelios Tigas ⁴ Dimitrios K Christodoulou ¹ Dimitris Kiortsis ¹

• ¹ School of Health Sciences, University of Ioannina, Ioannina, Greece
• ² Onassis Cardiac Surgery Center, Athens, Greece
• ³ Metropolitan General Hospital, Holargos, Greece
• ⁴ University Hospital of Ioannina, Ioannina, Greece

The detection of frequent premature ventricular contractions (PVCs) in an athlete represents one of the most important red flags in the context of pre-participation screening. We report a case of a 6-year-old asymptomatic male athlete practicing basketball and sailing, who was examined for pre-participation screening. His resting electrocardiogram showed very frequent isolated monomorphic PVCs. The morphology of PVCs was left bundle branch block with inferior axis and R/S wave precordial transition in lead V3. The most likely origin of PVCs was considered left ventricular outflow tract. The resting transthoracic echocardiography revealed reduced left ventricular systolic function with an ejection fraction of 43%, indicating the possible existence of PVC-induced cardiomyopathy. We detected 43,149 isolated monomorphic PVCs (PVC burden: 40%) on 24-h ambulatory electrocardiographic monitoring.Initiation of treatment with atenolol 12.5 mg twice a day leaded to inadequate reduction of PVCs, since there were 29,452 isolated monomorphic PVCs (PVC burden: 29%) on 24-h ambulatory electrocardiographic monitoring. After adding flecainide 25 mg twice a day to atenolol treatment, 24-h ambulatory electrocardiographic monitoring revealed the complete resolution of ventricular arrhythmias with no detected PVCs. The left ventricular systolic function recovered to normal. The athlete at an age of 12 years on combination therapy with atenolol and flecainide continued sports activity being completely asymptomatic and with normal cardiac examinations. The optimization of drug treatment was favored over ablation, since the athlete was a child and the probable origin of PVCs was the left ventricular outflow tract. This case report highlights that flecainide at a relatively low dose as add-on therapy to beta-blocker was highly effective and safe for the treatment of high burden PVCs originated from ventricular outflow tract in a juvenile athlete.