What country song is this?

I heard a song on the radio the other night and it was in a countdown of some sort I tried to remember it but I can't think of it for nothing. It was sang by a man (not an a new singer but not someone whos been around for ages) and it had a slow, nice beat; he sang about his heart, or trusting her not to break his heart and i think he promised to love her forever please help!