Objective      To determine the efficiency and safety of Watchman occluder for left atrial appendage (LAA) occlusion in nonvalvular fibrillation atrial patients.       Methods      Clinical data of the patients undergoing LAA occlusion with Watchman occluder in our hospital from August to September 2014 were collected. Then the baseline information

measured data of LAA from ultrasound and visualization

and the results of interventional procedures were analyzed.       Results      Twelve patients were included in this study

including 6 males and 6 females

at an average year of 66.4±14.5 years old (51 to 81)

and having AF for an average duration of 2.78±4.12 years (0.5 to 7)

and all of them were successfully operated (100%). The average CHA2DS2-VASc score was 4.1±1.9 (ranging from 2 to 6). The maximum LAA ostium was 19.7±2.2 mm by trans-esophageal echocardiography (TEE)

and 20.1±2.3 mm by LAA angioplasty. There was no significant difference in the maximum ostium of LAA between the 2 measurement methods (P0.05). The average diameter of the 12 implanted Watchman occluders were 25.0±3.2 mm. TEE indicated that the average maximum diameter of the implanted occluders was 20.3±5.8 mm

with a maximum compression ratio of (22.1±3.9)%. There were 6 patients showing a small amount of residual shunt

but having no other operation-related complication.       Conclusion      Watchman occluder is safe and effective for LAA occlusion. But it is necessary to be performed under the indications and followed the practices strictly.