second heart sound

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sec·ond heart sound (S2),

the second sound heard on auscultation of the heart; signifies the beginning of diastole and is due to closure of the semilunar valves.
Synonym(s): second sound

second heart sound

Cardiology A heart sound that corresponds to closure of the semilunar–pulmonary and aortic valves, which is a short, higher pitched “dubb”. See First heart sound, Fourth heart sound, Third heart sound.

sec·ond heart sound

(S2) (sek'ŏnd hahrt sownd)
The second sound heard on auscultation of the heart; signifies the beginning of diastole and is due to closure of the semilunar valves; auscultated at base of heart.
References in periodicals archive ?
The two sounds are added together, but the second sound does not exactly match the first sound in time.
Had the traditional press silenced the candidates' voices by compressing their views into eight or 12 second sound bites?
All candidates will be invited to be guest authors, giving them the opportunity to speak directly to the people through the blog format, rather than the standard 10 second sound bite format.
The guitarist, a handsome enough piece of ageing beefcake, is a top level session man who thinks a million notes a second sound great.
America Online and CompuServe users will be able to download a 30 second sound "byte" from "Tore Down," the first single from the album, beginning Wednesday, Aug.
We've learned how to keep them interested -- we've earned their attention -- so we don't have to play by the time constraints that govern the 15-second spots or nine- second sound byte.
Candidates are moving beyond the six second sound bite to the megabyte.
The second sound, known as shvarim, consists of three equally short blasts.
Extended functions, enhancements to the very successful MC44353/4/5 family that exists today, include Logic Output Port (2mA that can be used, for instance, to drive an attenuator), internal VCOs, improved attenuation with Output Inhibit, Second Sound subcarrier Input (Stereo or NICAM) plus a Power-On Default Mode for CH36(B/G) without the need for I2C bus programmation.
The University of Washington's Applied Physics Laboratory, which put the sound source on the Pioneer Seamount for the ATOC project and is about to put a second sound source in Hawaii.
Very attractive and unique plaque measures approximately 13"x15" and holds an autographed forensically authenticated 8x10 photo signed by Sammy Sosa with his#21 added, an engraved nameplate, and a card that when pressed plays an approximately 15 second sound clip of Sammy's 66th home run of 1998.