Hi, I am a 76 yr old female who is 100% dependent on my St June 2210 pacemaker/generator. It was implanted at the end of 2009, and after the initial healing/ caution period, I can say I have lived and slept without problems. I get a little short of breath when I walk too fast, or lift something a little heavy, but I'm no kid anymore so I can't blame the pacemaker. As for sleeping, I sleep on my left side (same side as the unit) about 80% of the time and have never had a problem. Common sense would tell us to sleep on our backs for about 6 weeks at first to allow tissue to heal around the leads etc.