Described herein are tissue closure devices and methods for ligating a target tissue, such as the left atrial appendage. The tissue closure device may have an elongate body, a snare at least partially housed within the elongate body, a suture at least partially housed within the elongate body, and a tightening element coupled to the suture. The suture may have a suture loop, and the tightening element may be configured to decrease the size of the suture loop when the area of a tissue within the suture loop decreases.
