<h1><span>TEXT</span></h1>

h1 {
  position: relative;
  overflow: hidden;
  text-align: center;
}
h1 span {
  display: inline-block;
  vertical-align: baseline;
  zoom: 1;
  *display: inline;
  *vertical-align: auto;
  position: relative;
  padding: 0 20px;
}
h1 span:before,
h1 span:after {
  content: '';
  display: block;
  width: 1000px;
  position: absolute;
  bottom: 5px;
  border-top: 3px solid #23284c;
}
h1 span:before {
  right: 100%;
}
h1 span:after {
  left: 100%;
}