Final answer:
In a client with heart failure, overfilled ventricles failing to accept blood from the aorta may cause an additional heart sound known as S3, which is different from the S1 and S2 heart sounds that correspond to the closing of the heart's valves.
Step-by-step explanation:
In a client with heart failure, overfilled ventricles unable to accept blood from the aorta may cause an additional heart sound known as S3. The normal heart sounds include S1, which corresponds to the 'lub' and is associated with the closing of the atrioventricular valves during ventricular systole, and S2, which corresponds to the 'dub' and is associated with the closing of the semilunar valves during ventricular diastole. The third heart sound, S3, is sometimes called the 'ventricular gallop', and while it can be normal in young individuals, athletes, or pregnant people, in older individuals it may be a sign of congestive heart failure. By contrast, the fourth heart sound S4 occurs when the atria contract to push blood into a stiff or hypertrophic ventricle, signifying left ventricular failure, and is not related to overfilled ventricles failing to accept blood from the aorta.