How To Treat Neuro Cardiogenic Syncope?

Hello. This morning my 13 year old son was diagnosed with neuro cardiogenic syncope. Since he was 1 1/2 years old he's had many episodes where he has passed out and stopped breathing and his heart stopped. Today he underway the treadmill stress test. All indicators were fine during the test. However, following the test, while resting, he passed out again, and the monitors showed that his heart stopped for about 45 seconds. We are starting the treatment process, but my question is neuro cardiogenic syncope life threatening? Thank you