I noticed a faint sound that lasted the duration of systole in a male runner. I only heard it at the pulmonic area and it had a mild crescendo effect. HR=45, BP 102/65...he's a runner. It didn't sound like any of the murmurs I've heard on the heart sound tutorials. I'm trying to learn what is normal and what the physiology of this sound might be. What should I be considering? My guess: Stroke volume large enough to cause audible flow.