What do extra heart sounds, such as S3 and S4, commonly signify?

Extra heart sounds, specifically the third heart sound (S3) and fourth heart sound (S4), are indicative of specific physiological changes in the heart, with S3 being associated with increased fluid states and heart failure. S3 often occurs due to rapid ventricular filling as the heart struggles to pump efficiently, which is often a sign of heart failure or volume overload conditions. In a healthy heart, S3 is usually not present; however, in patients who are experiencing heart failure, this sound becomes more pronounced due to increased pressures within the ventricles.

S4, on the other hand, arises from vibrations of the ventricular walls due to an atrial contraction against a stiff or hypertrophied ventricle, often seen in conditions such as hypertension and heart failure as well. Both S3 and S4 are useful clinical markers in diagnosing heart conditions, particularly heart failure, guiding healthcare professionals in assessing the severity of heart dysfunction.

While arrhythmias can produce irregular heart beats, the specific sounds associated with S3 and S4 are not typical features of arrhythmias. Myocardial infarction may lead to abnormal heart sounds, but it does not specifically relate to the presence of S3 or S4. Similarly, valve strain can result