When considering heart murmurs seven key attributes need to be considered. These are: whether it is systolic (because diastolic murmurs are always a problem), whether it is small (as in heard in only a limited area), whether it is soft (as in having a low amplitude), whether it is single (as in only a murmur, with no other abnormal sounds like a click or gallop), whether it is sweet (rather than a harsh sound), whether it is short in duration, and whether it is sensitive to posture or type of breathing of the patient (Bronzeitti & Corzani, 2010).
In the heart cycle, S1 corresponds to the first half of the sound of the heart beating—normally a “lub-dub” kind of sound. Thus, S1 corresponds to the “lub” part of that sound, when the atrioventriclar valves are closing (Cherif, Debbal & Bereksi-Reguig, 2008). This is the start of the ventricular systole period in which the ventricles are contracting. S2 corresponds to the “dub” part of the sound and corresponds to the aortic and the pulmonary valves closing (Cherif et al, 2008).
The most common type of functional heart murmur in adults is aortic stenosis which causes a harsh, sharp sound (crescendo to descrescendo) after S1, which is usually easiest to hear over the second right intercostal space and which radiates out to the carotid arteries (Grimard & Larson, 2008). Also there’s often a murmur at the upper right intercostal space that increases when the patient squats, but decreases when the patient stands (Grimard & Larson, 2008). It tends to be louder during periods of expiration (stage 4), but can be easily heard also in the first two stages of the cardiac cycle when the ventricles are relaxed. Another feature is that S2 tends to have decreased intensity (Grimard & Larson, 2008).