Thanks for seeking guidance through HCM,
Visibility of the pulsating heart by naked eyes is common in skinny children.That should not scare you, but if he complains of pain off and on in his chest then one should seek opinion of a pediatrician
. And some investigative workup to be carried out like ( Color Doppler Echocardiography
. ECG, SPO2, ASO titre ) to rule out any l anomaly.
Thank .I hope i have cleared your doubts