BEIJING, China, Nov. 9 -- A Chinese mother had a close encounter with death as her son's inability to solve a math problem led her to have a heart attack.

The 36-year-old Wang was helping her son with his primary school homework when she got enraged as he struggled to grasp the solution despite repeated explanations.

"I explained it to him many times but he still couldn't get it. I was so angry that I could explode. Suddenly, my heart was palpitating and I couldn't breathe properly," she told media.

She immediately called her husband, who rushed her to the hospital where she was diagnosed with myocardial infarction or a heart attack.

Dr. Yang Xiaoxue, at the Xinhua Hospital's internal medicine department, said, "She caught it in time....