Can the heart murmur from aortic stenosis come and go?

Variance: A murmur intensity can be altered by different states such as by fluid status, tachycardia, bradycardia, standing, squatting, hand grip tightness, or by bearing down (Valsalva maneuver). The assessment of a murmur may be variable to a degree, such as from a nurse practitioner vs a cardiologist. Some professionals use electronic stethoscopes, so care is done to ensure careful assessment.