I would have it checked out immediately, especially if it has happened on more than one occasion.
The swooshing sound is a definite sign to go to the doctor. Everyone has a small hole in their heart when they are born, but it doesn't always get closed properly. It's not a big deal, but if you don't catch it early, it could be. It usually starts to show itself around the teenage years. The testing requires only an echocardiogram, which is like an ultrasound of the heart.
The thing is I've already been to the doctor several times in the past 18 months. I've been suffering from severe anxiety related to worrying about my heart and even seen a cardiologist, had a physical check-up, ekg/ecg several times, two chest x-rays and a blood test which were all normal, but no echocardiogram. I'm always worrying about a new thing so you can understand I was worried when I pressed hard against this area whilst inhaling deeply and heard this noise, but do you think any problem would have been detected in the previous check ups? I've suffered from exhaustion and dizziness which is supposedly due to me worrying about things constantly and psychosomatic. I'm reluctant to visit the doctor again as I think I'm seen as a bit of a hypochondriac. A site I posted on said it could be possible to hear the sound when inhaling deeply as the increased lung pressure amplifies any heart sounds. Any ideas???