hello dr.,i wanted to inquire regarding heart,my father had gone for a by-pass surgery in 2002,almost 12 years back,now a days he is feeling a little discomfort in chest,like he feels heaviness in heart n dysnia too at times n breathlessness...his heart is 40 percent functioniong,sugar is at a high,what can be done ..is angiography the best way looking at by putting stent...