Coated and fissured tongue

[Vasalji]

Since last few days I am observing that when I get up in the morning my tongue is coated white. I clean the tongue with a tooth brush and the white coating disappears and the tongue remains in natural pink colour throughout the day. Secondly, there is a small crack in the middle forefront of the tongue. My age is 81 years. I am not diabetic and my blood pressure is normal. I have had angioplasty done 5 months ago and now I am on heart related medicines Nitroglycerin, Clopidogrel+Ecosporin and Atorvastatin. I wear artificial denture. Last month I had surgery for cataract in my eye. My evacuation system is working fine, although sometimes I miss a day or two. I do not take any medication for this and the bowl movement becomes regular on its own. I want to know the reason for white coating on my tongue and the crack in it.