What Causes Shivering In My Father's Hand?

My father's right hand has been shivering intermittently for some days now and along with that he gets uneasiness in his chest. He had severe cold and cough for about 10 days before this, Few days before that he also had chest pain. He has high BP but apart from that, no other known heart disease. What is the cause of this shivering and uneasiness?