The heart has a lot of different kinds of sounds. The combination varies, making it more complex to figure our what the heart is implying. The diversity may discourage physicians to learn auscultation. Nowadays, there are few cardiologists who are boating of skills enough to realize the heart sounds.In my opinion, however, heart sounds are so impressive and still worth learning. In order not to get lost in the deep field of heart sounds, focusing on a specific sound may be a good way for a beginner.
A fourth heart sound, as shown in the left phonocardiogram with apexcardiography, is one of my recommendations among sounds produced by the heart.
The fourth sound is common in hypertrophied ventricles, such as hypertrophic cardiomyopathy and aortic stenosis. It should also be kept in mind that it can be audible in the acute phase of ischemic heart disease.
To my knowledge, there is no definitive evidence to support that the presence of the fourth heart sound is associated with an increased risk of adverse outcomes in patients with hypertrophic cardiomyopathy.