The idea of a heart symbolizing love is something along the lines of the change in heart rate or whatever (I'm not too familiar with the specifics). There is a correlation between emotions and our physical heart. Often, I find that I can feel the emotions in my heart. Either my heart feels like it's breaking, or it feels heavy, or it feels like it's been stabbed, etc. As for positive emotions, I can obviously feel it beating quicker when I'm excited or see the person I love. And then there's this state of contentment that is a feeling in itself.
Can any other Fi-Dom, or just anyone, relate to this?