I have this pretty strong irregular pulse on the left side of my body and i feel it pretty regularly when lying on my back. i went to a cardiologist for chest pain 2 weeks back and he did an echocardiogram and an ekg and everything came back fine.

Pulse on left side: Can tell if it is a pulse by placing finger on the pulsation and a finger on your radial pulse ( thumb side of wrist), if they are synchronous possibly a pulse, if not may be gastric movement(reflux-GERD-try ranitidine/prevecid) or colon or muscle ( check electolytes). If very thin could be aorta ( normal) and in cases like Marfan's may be aortic aneurysm( sonogram or CT anigo) f/u w/ doc

? Arrhythmia?: Irregular heart beats can be intermittent. When you perform an EKG in an office setting you may not pick up an intermittent finding. Talk to your doc about having a "Holter monitor" done. They can be put on you and record your heart for from 6 hours up to a month. If you truly have an arrhythmia that should pick it up.

Arrhythmias : You may need a Holter done as well to see whether you have Pvc s occasionally