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
1 A set is a subset of another set when all the elements in the first set are also a member of the second set. 2  Given sets and, is a subset of, notated as, if and only if for all, implies. 3  All sets are subsets of the universe. If A and B are two sets, then difference of A and B is the set A-B consisting of all the elements which are elements of A but are not elements of B. 2  Complement of a set A, written as A' or A C is the set consisting of all the elements of which do not belong to A. 3  Thus A' = {x | x and xA}.