I am suffering from mild aortic stenosis and nowadays i am feeling like my heart beat only do lubb sound for sometimes and after that it makes lubb dubb sound.should i worry about that.an also i am suffering from an anxiety too?

Have you had an echocardiogram? . As your 4 heart valves open and close, there should be a lubb dubb with each heart beat. It takes very severe aortic valve scarring for the second heart to be muffled when we listen at the upper left sternal border with a stethoscope & a heart murmur is usually prominent. A cardiologist would have to evaluate and advise you.

That's your feeling, aortic stenosis does not manifest that way when the stenosis gets worse. Yes, you are probably anxious.