Heart and Lung Sounds Reference Guide Aortic Pulmonic Erb's Point Tricuspid Mitral Lungs Third Heart Sound Gallop - Abnormal Auscultation Reference Signup Now. Unlock lessons and more. SignUp Patient Normal Speed play pause Patient Half Speed play pause Simulated Full Speed play pause Lesson For heart sounds listen to the synthetic sound while reviewing this lesson. A third heart sound occurs early in diastole. In young people and athletes it is a normal phenomenon. In older individuals it indicates the presence of congestive heart failure.The third heart sound is caused by a sudden deceleration of blood flow into the left ventricle from the left atrium. In the anatomy tab you will see a thin-walled, dilated left ventricle with generalized decreased vigor of contraction.In the presence of a third heart sound (S3) the first heart sound is decreased in intensity while the second heart sound is increased in intensity.The third heart sound is a low frequency sound best heard with the bell of the stethoscope pressed lightly on the skin of the chest. The waveform(s) seen above are a chart of sound amplitude (loudness) on the vertical axis against time on the horizontal axis. Listening Tips A summary of the key aspects of this heart or lung sound. S1: Reduced intensity. S2: Increased intensity. Diastole: S3 early in diastole, low pitched, heard during expiration. Auscultation Method The recommended patient position is supine For this sound, use stethoscope's bell The recommended auscultation position for the stethoscope is mitral Relevant Courses If you wish to review a complete mobile concerning Third Heart Sound Gallop - Abnormal Auscultation Reference and related heart sounds, the modules(s) listed below may be useful. Each lesson includes text that explains the auscultatory sound and its clinical significance. The lesson also includes an audio track for playback. A waveform provides a great way to visualize the sounds. Finally, we also include an animation video. For heart sounds, the video illustrates heart muscle and valve movements along with blood flow. For lung sounds, the primary source of the sounds can be seen. Each module also includes a quiz. Extra Heart Sounds (S3 and S4)25 Auscultation in Primary Care31 Third Heart Sound Gallop - Abnormal Auscultation Reference