I know the "muscle squeeze" sensation all too well. I'm 34, and I've been dealing with PVC's/PAC's since my early teen years. For me, they come in bunches, maybe 4-5 a minute, then they stop. Most times i feel it directly in the center of my chest, other times in my neck. Sometimes it feels like it starts low and works its way up, kind of like a prolonged fluttering, like a bass guitarist working his fingers up the neck of his instrument. The "squeeze" ones in the middle of the chest are the worst, because they kind of jolt you. Like many of the people who post on this website, I've been told by doctors that they're benign and to ignore them, but i've yet to figure out a way to do that.
Yes I know what your talking about. Thats one of the many sensations I get. I guess were just lucky, it seems according to my Dr. the only problem I have, is that I feel the PVC's. Has the lexapro helped with the frequency of your palpitations. Some people say that antidepressants have helped them. I would definately go that route if it would help.