Objective:To study the learning curve of percutaneous patent foramen ovale (PFO) occlusion guided solely by transthoracic echocardiography (TTE), as well as the success rate and safety of the learning curve.Methods:To retrospectively analyze these patients with indications for PFO occlusion admitted in our department from April 2021 to April 2022, and obtained 100 samples the author's initial cases guided solely by TTE, including 25 men and 75 women, with a mean age of (48.22±10.44) years old.Analyze preoperative baseline data: gender, age, height, weight, body mass index, the tunnel length and size of the PFO measured by transesophageal echocardiography, the grade of contrast-transcranial doppler test, combined atrial septal aneurysm, etc.Operation time, success rate, and complications were analyzed in all patients.Results:With the accumulation of cases, the operation time gradually shortened, accumulated to about 50 cases, the operation time has significantly shortened ( P<0.05), and the learning curve was leveled off after 50 cases ( P<0.05), there was statistical difference.The comparison of the success rate and complication of cases within the learning curve and those after completing the learning curve was no statistical significance( P>0.05). Conclusion:The learning curve of percutaneousc closure of patent foramen ovale guided solely by TTE is long, requiring about 50 cases to complete the learning curve. The success rate and safety of the learning curve are high. This procedure is worth popularizing.

Objective: To identify the definition of heat wave based on mortality risk assessment in different regions of China. Methods: Daily mortality (from China Information System for Disease Control and Prevention) and meteorological data (from National Meteorological Information Center in China) from 66 counties with a population of over 200 000 were collected from 2006-2011. With the consideration of climate type and administrative division, China was classified as seven regions. Firstly, distributed lag non-linear model (DLNM) was used to estimate community-specific effects of temperature on non-accidental mortality. Secondly, a multivariate meta-analysis was applied to pool the estimates of community-specific effects to explore the region-specific temperature threshold and the duration for definition of heat wave. Results: We defined regional heat wave of Northeast, North, Northwest, East, Central and Southwest China as being two or more consecutive days with daily mean temperature higher than or equal to the P₆₄, P₇₁, P₈₅, P₆₇, P₇₅ and P₇₇ of warm season (May to October) temperature, respectively, while the thresholds of temperature were 21.6, 23.7, 24.3, 25.7, 28.0 and 25.3 ℃. The heat wave in South China was defined as five or more consecutive days with daily mean temperature higher than or equal to the P₉₃ (30.4 ℃) of warm season (May to October) temperature. Conclusion The region-specific definition of heat wave developed in our study may provide local government with the guidance of establishment and implementation of early heat-health response systems to address the negative health outcomes due to heat wave.