"Yet despite being the UK's single biggest killer, the first sign someone has heart disease is often severe chest pain or sudden death".

BBC: Dundee researchers develop tests for early heart disease

The disease is the leading cause of heart-related sudden death in people under 30.

CNN: Blaming others can ruin your health

Secondhand smoke can increase the risk of respiratory ailments, lung cancer, and heart disease in nonsmokers, and the risk of sudden infant death syndrome and middle ear infections in children.

CNN: Sinus trouble? Secondhand smoke may be to blame

The benefits in terms of sudden cardiac death reduction are there for all women, not just those with established heart disease.

BBC: Light smoking 'doubles sudden heart death risk in women'