Chhun Socheata from Cambodia said she found it hard to breathe and was constantly tired. She even collapsed once while walking.

The 7-year-old girl was diagnosed with congenital heart disease and has been on medication for years. She could not get the corrective surgery she needed because the local hospital does not have the required facilities.

In July 2019, Socheata was flown eventually to FuWai Yunnan Cardiovascular Hospital in Kunming, capital of southwest China's Yunnan Province, for operation after being screened by a Chinese doctor in Phnom Penh, Cambodia's capital city. After a lengthy recovery, she went back to school for the first time, at the age of nine.

Congenital heart disease may be linked to a mother's health during pregnancy, said Pan Xiangbin, executive president of FuWai Yunnan Cardiovascular Hospital.

Because of the poor socioeconomic conditions in Myanmar and Cambodia, women may often work in unsafe conditions during pregnancy, with possible exposure to toxic chemicals with the risk of a higher possibility that children are born with congenital heart defects, he added. 

Chhun is among around 4,000 children with congenital heart diseases treated by FuWai Yunnan Cardiovascular Hospital, part of a medical program launched by the China Charity Foundation under the framework of the Belt and Road Initiative. Launched in 2017, the program aims to provide free surgery to children with heart disease in Southeast Asia at two partner hospitals in China, Beijing Anzhen Hospital and Fuwai Yunnan Cardiovascular Hospital.

In China, all newborns are screened for congenital heart disease at birth, or during the early years of their lives. Yet this is impossible to realize in Myanmar and Cambodia because of a lack of medical professionals and quality health facilities, Pan said.

Many serious heart problems go undiagnosed until children start to show symptoms, such as blue-tinted nails or lips, increasing fatigue and shortness of breath. While conducting screening in rural areas of Myanmar, the team led by Pan identified many children with undiagnosed conditions.

"Congenital heart diseases are silent killers," he noted. "Early detection is thus key to the treatment."

But many of those conditions went undetected, despite the prevalence of medical aid teams from foreign countries in Southeast Asia. Because of the risks and challenges inherent in open-heart surgery used to repair defects that occur inside the heart, most medical aid teams are reluctant to perform surgeries for children with congenital heart diseases, said Duo Lin, head of the research department of chronic diseases at Fuwai Yunnan Cardiovascular Hospital.

Compared with medical practitioners from the U.S. or Europe, Chinese doctors perform minimally invasive surgeries that reduce risk and shorten the recovery in comparison to invasive surgeries, he added.

The cost of the surgery, an average of $20,000, can be overbearing for families in Southeast Asia. Sokchea LY from Cambodia had her disease diagnosed at the age of 17, at a late stage that makes surgery highly risky. At 19, she finally underwent surgery by doctors from China, with her operation and travel cost entirely covered by the program.

"It requires an entire system to help a patient go through the open-heart surgery," Duo said. "Not only does the doctor have to perform the surgery well, but close monitoring and immediate post-operative support are also integral to the recovery of the patients," he noted when explaining why patients often have to fly to the neighboring Yunnan Province for the operation. 

The program has now screened 300,000 villagers in Myanmar and Cambodia. It has also trained hundreds of obstetricians from Myanmar and Cambodia to perform heart surgery.

The program is part of China's medical aid program that dates back to the 1960s. After sending the first medical aid team to Algeria in 1963, China had dispatched 26,000 medical workers to over 71 countries by July 2018, according to data from National Health Commission.

Health has also been an integral part of China's cooperation with Southeast Asian countries. The medical aid program to treat children with congenital heart disease initially received lukewarm responses from residents in Myanmar and Cambodia, due to a lack of trust in the quality of Chinese medical services.

"The first batch of patients expressed their strong reservations, and doctors from Myanmar even accompanied them to China for their medical treatment," Duo recalled.

With the improvement in Chinese medical services, the types of medical aid offered by China also expanded from simple treatment of physical injuries to treatment of non-communicable diseases to difficult surgical operations involving the heart, cancer, limb replantation and other areas. Amid the pandemic, China provided mask donations to Southeast Asian countries, along with free and subsidized provision of vaccines and other medical aid.

"The impact of medical diplomacy is tangible and visible, and thus it would not be tarnished by political or racial divide," Duo noted. 

Chhun Socheata's mother said she cannot imagine what the life of her daughter would be like without the operation. "I am so grateful that she has fully recovered today," she said.