This technology includes an interventional device to occlude the left atrial appendage to prevent thrombus formation. Atrial fibrillation is the most common cardiac arrhythmia and is associated with formation of thrombus in the left atrial appendage. Standard preventative treatment involves anticoagulation, which is not tolerated by all patients. Existing devices necessitate improvement because they need trans-septal puncture and anticoagulation to prevent thrombus or are prone to life-threatening complications. All existing devices can cause left atrial appendage perforation leading to cardiac tamponade, requiring urgent intervention. This device is designed to ligate and exclude the left atrial appendage from the left atrial cavity within the pericardial space. The left atrial appendage is then grasped with one limb of the device. The second limb deploys a suture and, using counter-traction between the two limbs, the suture is delivered to the base or neck of the left atrial appendage where it is tightened and secured. The suture is then cut, and the right atrial appendage puncture is sealed.