Heart sounds


Where S1 and S2 fall in the cardiac cycle and how they correspond with the EKG rhythm. I’ve also included where and why S3 and S4 fall.

S3: dilated ventricle, usually due to heart failure, though it can be normal in children

S4: the sound is caused by blood entering a ventricle with decreased compliance.
A patient with atrial fibrillation can’t have an S4 because there isn’t enough coordinated atrial contraction to force enough blood into the ventricles at once

Important aspects of the cardiac history

Just some important things to ask about when you suspect a patient has a cardiac problem. The risk factors are very important to ask almost everyone (because practically everyone in North America is at risk for/has heart disease).