I have also had the chest vibrations, about 6 years ago. Along with the vibrations came Supra Ventricular Tachycardia. (pulse 200+). After consulting with my cardiologist he performed an ablation. One lead to my heart was closed, so the misfiring of the leads to the heart could be controlled. After 6 yrs. I am again feeling the vibrations and am headed back to the doctor. The next step may be a pacemaker.
I was told that this condition is hereditary.