What is the point of maximal impulse (PMI) considered enlarged or sustained?
Often students and residents quoted coin sizes as being reference standards (e.g. dimes and quarters). However, it does not take into account the different body sizes (e.g. mini-me vs. Yao Ming). Not to mention there are non-North Americans who may not be familiar with the size of a quarter or dime.
A better way is to use the patient’s body landmark as an internal reference.
A PMI is considered enlarged when it is bigger than one intercostal space, i.e. when the PMI can be felt in two or more intercostal spaces.
A PMI is considered sustained when the PMI can be felt more than 2/3 of the systole or if PMI reaches or exceeds the second heart sound.