Let’s talk about 5-Lead EKG placement and Auscultation of Heart Sounds.
There are 5 electrocardiogram leads we use traditionally to get tracings of the heart for telemetry and cardiac monitoring. Many times, your leads may actually have letters on them telling you where to place them. For example, RA for Right Arm, LL for Left Leg or Left Lower. However, in the event that you only have colored leads, it is important to know which leads go in which locations. The way we usually remember this is: White on the Right (so that’s the first lead you place), Snow over Trees (or Clouds over Grass) so the green goes on Right Lower, and then Smoke over Fire. So you’ll place the black lead on the left upper, and red on the left lower” Then, as many women know, we always want to keep chocolate close to the heart! So brown goes in the middle. Proper lead placement allows for accurate tracing of the electrical activity of the patient’s heart. Improper placement could lead to misdiagnosis of electrical abnormalities and unnecessary tests and treatments.
Now, there are 5 main locations we use to auscultate the heart. You can remember them by using the mnemonic APE To Man (A-P-E-T-M). It stands for Aortic, Pulmonic, Erb’s Point, Tricuspid, and Mitral. The Aortic location is in the 2nd intercostal space, right sternal border. Pulmonic is the 2nd intercostal space, left sternal border (just jump straight across the sternum). Erb’s Point is the 3rd intercostal space, left sternal border (just come down one intercostal space). The Tricuspid location is the 4th intercostal space, left sternal border (down one more). Finally, the Mitral location is the 5th intercostal space, midclavicular line (so you come down one intercostal space, and over to the midclavicular line).
These locations allow us to listen to the closing of the 4 valves of the heart. The Lub or S1 signifies systole and the Dub or S2 signifies diastole. Because we know that the Aortic and Pulmonic valves close during diastole, we will find that we hear S2 louder in these locations. In the same way, the Mitral and Tricuspid valves close during systole, therefore we will hear S1 louder in those locations. The best location to hear a strong S2 is Erb’s Point. Remember these locations when you begin learning about murmurs, it will help you understand the physiology behind the murmur you’re hearing!