Define the fourth heart sound. It is heard right before S1 late in diastole and sounds like ventricular filling. Sounds like da LUB-dub. It can be heard on the apex in the left lateral position. It is normal in people over the age of 40-50. Usually heard after exercise with no CV disease. Abnormal sounds like an atrial gallop.
Define subset. subset synonyms, subset pronunciation, subset translation, English dictionary definition of subset. n. A set contained within a set. n 1. maths a. a set the members of which are all members of some given class: A is a subset of B is usually written AâB b.... Subset - definition of subset by The Free Dictionary
Well, you're a subset if every member of your set is also a member of the other set. So we actually can write that B is a subset-- and this is a notation right over here, this is a subset-- B is a subset of A. B is a subset. So let me write that down. B is subset of A. Every element in B is a member of A. Now we can go even further.