According to the above description provided, It appears to be 'bradycardia
In youngsters this might be asymptomatic & benign condition & a simple way to correct it temporarily may be overdrive pacing, meaning running, which increases the heart rate
& thereby reduces the symptoms.
But if it continues to be problematic a better choice would be to have a permanent pacemaker implant.
If with further investigations, an anomalous pathway is found then RFCA- radiofrequency catheter ablation
would be curative treatment. So, please have a consultation with an eminent cardiologist to undergo further investigations. Thanks & take care!