Yes, stress can cause heart palpitations because when you are stressed, your body releases a hormone called adrenaline which makes your heart beat faster. But, it could be something else too like too much caffeine or alcohol, certain medications, asthma inhalers, dehydration and other health issues.....

in that case as mentioned above surgical treatment not required.

No, it is not safe to smoke or take any kind of drungs when you are unwell. If may have extensive adverse effects as your immunity is already low.