the period from the beginning of the QRS complex to the first (aortic) vibration of the second heart sound. Synonym(s): QS2 interval
e·lec·tro·me·chan·i·cal sys·to·le
(ĕ-lek'trō-mĕ-kan'i-kăl sis'tŏ-lē) The period from the beginning of the QRS complex to the first (aortic) vibration of the second heart sound. Synonym(s): QS2interval.