Does the strength of one's heart increase in propotion to addition of muscle mass? Your heart would have to work harder to sustain the added mass obtained through lifting, right? As far as cardiovascular optimum health is concerned are you still in good standing with your old ticker by adding the weight.
The answer to this from anecdotal evidence only is "yes" the heart grows and "yes" it's a good thing.
Heart hypertrophy by itself can be a bad thing (google it), but when linked to exercise, it's a good thing. My reasoning for this is that fit people typically live longer, healthier lives than slugs.
Your heart will surely grow and adapt to exercise in many ways: stroke-volume (amount of blood) will be one of the things that increases. Your energy system (oxygen delivery, lactic acid tolerance, oxygen-debt management etc.) will also change (improve) with exercise - assuming you don't have an underlying medical condition of course. "Always consult your doctor" blah blah blah.
Did you have a specific concern? If so, you might try the Locker room (Dr Ryan would be a good start).
Being bigger probably puts more strain on your heart.
Of course sitting on the couch doing nothing does too...
Thanks WiZ,just what I needed to know. I have no specific concern. It was just a question a friend threw out at me since I was trying to convince him to pack on a little beef with one of the programs here on T-Nation. It was sort of an optimum health vs. beefy body question. Thanks again, I'll have him read this.