What is the difference between a heart attack and cardiac arrest?

What is the difference between a heart attack and cardiac arrest? Can the body show warning signs before a heart attack? What should you do if someone suddenly collapses?
In this special health interview, Dr. Tarun Kumar, Cardiologist at Medanta-Moolchand, explains the key differences between heart attack and cardiac arrest, warning symptoms, emergency response, CPR, heart-healthy nutrition, and the effects of smoking and alcohol on cardiovascular health.