Was it a congenital defect that killed de Nigris?

Last night I linked to preliminary autopsy reports out of Greece that said that Mexican striker Antonio de Nigris died as the result of a congenital heart ailment. Today, de Nigris' personal doctor, who is also a cardiologist, denied the claims. Dr. Mario Benavides said that de Nigris was completely healthy and had not registered any heart condition or related health problems.