After talking on the phone for several minutes my voice will become soft as if it takes extra effort to speak. After this I feel the need to breath deeply for several minutes. At this time I generally have pain on the Right side of my chest.I feel winded and tired for several minutes. The only other time this occurs is when I exert energy for several minutes .. for example: Dancing for just a couple of minutes. I am not over weight and in good condition so I am not sure what is going on. Is this possible a Lung or Heart issue ? Anyone have any ideas ?