I never had this before, It Happened few times in a month, I feel what it could an
heart murmur; a turbulence around the
heart area after each heartbeat, like whooshing noise, like if you were to flick one drum with a finger.
It also seems that when I have this I can hear less the "dub lub" sound of the heart when beating.
Happens after I exercise only, the first time that happened I was exerting quite a lot (running) as soon as I rest from the exercises, the murmur comes up.