Objective To observe the pathophysiological change of right heart remodeling model of beagle dogs caused by tricuspid regurgitation. Methods Six beagle dogs were separated to TR group and sham operation group randomly and equally. The anterior and posterior leaflets of tricuspid valve of beagle dogs from TR group were cut off under direct vision on the beating heart. The echocardiography data were measured pre-operation and post-operation 3, 6, 12 months respectively and autopsy results were acquired after the sacrifice of two animals who had been raised for 18 months. Results The operation was successful and survival 100%. The weight of TR group increased, and the echocardiography showed right atrium and ventricle enlargement and right heart dysfunction. The autopsy of TR group found myocardial fibrosis , liver cirrhosis and ascites. All of the results indicated the occurrence of right heart remodeling and right heart failure. There is no significant difference in sham operation group before or after operation. Conclusion The myocardial fibrosis is one of the pathological basis of right heart remodeling.

Objective To investigate the safety and efficacy of transesophageal echocardiography assisted thoracoscopic left atrial appendage clipping in atrial fibrillation patients with high risk of stroke and bleeding.Methods Clinical data of 14 atrial fibrillation patients with high risk of stroke and bleeding from November 2021 to May 2023 was retrospectively analyzed.All the patients had suffered from cerebral infarction.The CHA2DS2-VASc score was 3-7(mean,5.0±1.4)and the HAS-BLED score was 3-4(mean,3.3±0.5).The thoracoscopic surgery was performed with two ports.The left atrial appendage clipping was performed by using a domestically produced E-Clip left atrial appendage closure system,assisted by transesophageal echocardiography.Results All the operations were successfully performed.The mean operation time was(39.6±7.7)min,the mean drainage volume after operation was(80.4±37.1)ml,and the drainage tube was removed at(26.0±2.5)h after operation.All the 14 patients were followed up for 3-21 months,with a median of 8 months.Complete closure of the left atrial appendage without residual leakage and no thrombosis in the left atrium were confirmed by transthoracic echocardiography.No new cerebral infarction or bleeding lesions in the brain was detected by CT scanning.The electrocardiogram showed that 2 patients converted to sinus rhythm and 12 patients still maintained atrial fibrillation rhythm.Conclusions Transesophageal echocardiography assisted thoracoscopic left atrial appendage clipping can completely closure left atrial appendage and avoid new onset of stroke in atrial fibrillation patients with high risk of stroke and bleeding.It can also play a role in electrical isolation of left atrial appendage so as to cure atrial fibrillation in few patients.