Auscultation in Primary Care

Fourth Heart Sound Gallop Sounds

The fourth heart sound occurs in late diastole just prior to the first heart sound.

The first heart sound is decreased in intensity and the second heart sound is increased in intensity.

The fourth heart sound is produced by an increase in stiffness of the left ventricle due to scar tissue formation. This may be a manifestation of coronary heart disease.

A fourth heart sound can also be caused by a greatly thickened left ventricular wall such as with essential hypertension or aortic stenosis. This is shown in the anatomy tab.

A fourth heart sound is never heard with atrial fibrillation because the contraction of the atria is ineffective in this condition.

The fourth heart sound is a low frequency sound best heard with the bell of the stethoscope pressed lightly on the skin of the chest.

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The recommended auscultation position for the stethoscope is the Mitral position. For this sound, use stethoscope's Bell.

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The recommended patient position is Supine

Phonocardiogram

This waveform plots sound amplitude on the vertical axis against time on the horizontal axis.

Heart Animation

Lessons

1	First and Second Heart Sounds - Normal and Unsplit
2	First and Second Heart Sounds - Reduced Intensity
3	Second Heart Sound - Splitting
4	Third Heart Sound Gallop
5	Fourth Heart Sound Gallop
6	Third and Fourth Heart Sound Gallop
7	Summation Gallop at 120 beats per minute
8	Second Heart Sound - Fixed Splitting
9	Mid-Systolic Click
10	Mitral Valve Leaflet Prolapse
11	Aortic Stenosis (Diamond Shaped Systolic Murmur)
12	Aortic Regurgitation (Decrescendo Diastolic Murmur)
13	Mitral Regurgitation (pansystolic Murmur)
14	Mitral Stenosis (Diastolic Murmur)

Practice Drill

Listening Tips
A synopsis of important sound features and timing for this abnormality.
S1: Reduced intensity.
S2: Increased intensity.
Diastole: S4 present - a low pitched sound.

CaseID	85
CourseID	25
CourseCaseOrder	2
ID	71