Clinical location of the fourth and fifth intercostal spaces as a percent of the length of the sternum

Abstract

Objectives: To verify accurate placement of the precordial ECG leads by identifying the 4th and 5th intercostal spaces as a function of the length of the sternum. This should decrease the percentage of lead misplacement leading to misdiagnoses. Methods: The population consisted of patients and healthy volunteers. The proposed method compared palpation of the 4th and 5th intercostal spaces to a percentile of the sternal length. Location of the 4th and 5th intercostal space using a simple device was evaluated to assist in proper placement of the precordial leads to obtain accurate diagnosis. Results: The location of the 4th and 5th intercostal space is related to the length of the sternum. It is 77% of the sternal length that measures 15 cm for the 4th intercostal space. The position of the VI and V2 electrodes decreases to 57% when the sternal length is 26 cm. Similar data was obtained to locate the 5th intercostal space with proper position of V4-V6 electrodes. Tables are provided to facilitate this process. An instrument was designed to measure the 4th and 5th intercostal space as a function of the sternal length. Conclusions: The location of the 4th and 5th intercostal space is identified based on the length of the sternum. (C) 2017 Elsevier Inc. All rights reserved.