There is absolutely no question that smoking is harmful and injurious to health and therefore, pacemaker or no pacemaker, one should not indulge in smoking. Regarding limitations of life, I think with pacemaker, one can do any thing and every thing that you are able to carry on with normal rhythm of the heart. So there are no limitations what so ever. However, as a precaution, when ever you are entering into strong magnetic fields like power station or other areas like high
tension transformers, then you may need to declare that you have got a pacemaker and may even need to keep away. Similarly, for MRI scanning also, you may have to declare to the doctor that you have got a pacemaker implantation. If you undergo any kind of surgery, then also you must tell your doctor because certain diathermies, which are used during surgeries, may interfere in your pacemaker function. Barring these minor precautions, I think you can lead a very normal and comfortable life and just put the implantation of pacemaker behind you and let it not interfere in your day to day life.