Examine the illustration and play the WAV file multiple times. It is more important to learn the cadence (pattern / timing) than the quality of the sounds at this point.
Remember and review the cardiac events as you listen. S1 is created when the ventricles contract and close the mitral and tricuspid. The left ventricle is capable of generating higher pressures more quickly and the mitral valve will close slightly before the tricuspid. Normally the two sounds slightly overlap and create one sound - S1. In some patients mild splitting can be heard normally, If the splitting of S1 is great, as it is in this example, it is usually due to disease.
Once you have the split S1 mastered, go on to the next case.
Updated: September 23, 1997