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* S3 and S4 heart sounds
 #577706  
  drwinusmle - 04/01/11 20:13
 
  Can someone pls explain S3 and S4 heart sounds?  
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* Re:S3 and S4 heart sounds
#2368397
  drwinusmle - 04/01/11 21:05
 
  Anyone pls,,jsut a brief summary?  
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* Re:S3 and S4 heart sounds
#2368455
  march2010 - 04/01/11 23:04
 
  The third heart sound (protodiastolic gallop, ventricular gallop) is benign in youth, some trained athletes, and sometimes in pregnancy but if it re-emerges later in life it may signal cardiac problems like a failing left ventricle as in dilated congestive heart failure (CHF). S3 is thought to be caused by the oscillation of blood back and forth between the walls of the ventricles initiated by inrushing blood from the atria. The reason the third heart sound does not occur until the middle third of diastole is probably because during the early part of diastole, the ventricles are not filled sufficiently to create enough tension for reverberation.

It may also be a result of tensing of the chordae tendineae during rapid filling and expansion of the ventricle. In other words, an S3 heart sound indicates increased volume of blood within the ventricle. An S3 heart sound is best heard with the bell-side of the stethoscope (used for lower frequency sounds). A left-sided S3 is best heard in the left lateral decubitus position and at the apex of the heart, which is normally located in the 5th left intercostal space at the midclavicular line.[2] A right-sided S3 is best heard at the lower-left sternal border. The way to distinguish between a left and right-sided S3 is to observe whether it increases in intensity with inspiration or expiration. A right-sided S3 will increase on inspiration whereas a left-sided S3 will increase on expiration.

fourth heart sound when audible in an adult is called a presystolic gallop or atrial gallop. This gallop is produced by the sound of blood being forced into a stiff/hypertrophic ventricle. It is a sign of a pathologic state, usually a failing left ventricle, but can also be heard in other conditions such as restrictive cardiomyopathy. The sound occurs just after atrial contraction ("atrial kick") at the end of diastole and immediately before S1, producing a rhythm sometimes referred to as the "Tennessee" gallop where S4 represents the "Ten-" syllable. It is best heard at the cardiac apex with the patient in the left lateral decubitus position and holding his breath. The combined presence of S3 and S4 is a quadruple gallop, also known as the "Hello-Goodbye" gallop. At rapid heart rates, S3 and S4 may merge to produce a summation gallop


Hope this help.
 
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* Re:S3 and S4 heart sounds
#2368456
  maryam2009 - 04/01/11 23:05
 
  S3 occurs in early diastole ,is associated with inc. filling pressure and in dilated ventricle,it is normal in children but it is pathalogic and an important sign/clue of CHF (like a stream of water flows forcefully into an ocean)

S4 occurs in late diastol or pre systole ,associated with high atrial pressure and concentric ventricular hypertrophy.....Left atrium must push against stiff LV wall(no more room to expand) like after Halloween party that your stomach is too full but you try to eat desert Golijan exampes:)
 
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* Re:S3 and S4 heart sounds
#2368535
  drwinusmle - 04/02/11 00:43
 
  thanks to both of you!! Which one of these is present in restrictive cardiomyopathy?  
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* Re:S3 and S4 heart sounds
#2368537
  march2010 - 04/02/11 00:47
 
  Hi
Your answer is already there so pls read the explanations given above.

thx
 
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* Re:S3 and S4 heart sounds
#2368541
  drwinusmle - 04/02/11 00:56
 
  Yes, I see it thx. However, I beleive that in restrictive both S3 and S4 could be present bcs. CHF is the most common cause of death in restrictive cardiomyopathy meaning that restrictive cardiomyopathy (S3 is present)--->CHF (S4 is present),,??  
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