Erb’s Point Explained

What is Erb’s Point?

As a medical assistant, you will do a lot of auscultating, or listening to, heart sounds. There are five points you should always assess:

• Aortic

• Pulmonic

• Erb’s Point

• Tricuspid

• Mitral

All of these are named after a cardiac valve, with the exception of Erb’s Point. It is important to listen to the heart sounds in this order to determine what valves may be responsible for any “extra” heart sounds, like murmurs.

The Location of Erb’s Point

Erb’s Point is found in the third intercostal space on the left side of the sternum. It is one intercostal space below where the pulmonic valve is auscultated.

As you move the stethoscope over the five points, you can hear the sounds from the respective valves. Auscultating will allow you to assess the rate and rhythm of the heart but, more importantly, the completeness of valve closure.

Why Erb’s Point Is Important

When auscultating heart sounds, the two main sounds are the S1 and S2 sounds. At Erb’s Point, you can usually hear both the S1 and S2 sounds. The S1 sound comes from the closure of the mitral valve and tricuspid valves. The S2 sound comes from the closure of the aortic and pulmonic valves. When the heart sounds are referred to as Lub-Dub, S1 is the Lub and S2 is the Dub.

The Other Erb’s Point

Historians argue which “Erb’s Point” should be attributed to the German neurologist Wilhelm Erb. While Erb’s Point most commonly refers to this important area for heart sound auscultation, there is also an Erb’s Point in neurology. This other Erb’s Point is where a group of nerves meet in the neck, and an injury to this nerve point can cause a specific type of arm paralysis called “Erb’s Palsy”. This injury is most frequently caused by shoulder dystocia during birth.