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
Euler diagram showing. A is a proper subset of B and conversely B is a proper superset of A. In mathematics, especially in set theory, a set A is a subset of a set B, or equivalently B is a superset of A, if A is contained inside B, that is, all elements of A are also elements of B. A and B may coincide. The relationship of one set being a subset of another is called inclusion or sometimes containment.