Left chest pain when briskly walking or uphill exercise. had ecg at hospital and was normal. jolts during sleep too as if my hearts stopping.worried. ?

Jolts are normal: Left chest pain on exertion should always be evaluated. It sounds like that was done based on your report of a normal EKG. This is unlikely to be related to jolts awakening you from sleep. Jerking awake suddenly, often with the sensation of falling, are referred to as "hypnic jerks". These are normal. They are more frequent when the patient is anxious or sleeping in a noisy environment.

Anxiety: most likey anxiety but get ultrasound of heart to make sure it is not life threatening hypertrophic cardiomyopathy disease leads to sudden death.

Mgt: This could be consistent with an intermittent irregular heartbeat. Additional testing may include a Holter monitor and/or stress test.