Progressive Care Nursing Certification (PCCN) Practice Exam

What does the fourth heart sound (S4) signify?

1. It occurs after ventricular contraction

2. It is best heard with the diaphragm of the stethoscope

3. It is a normal finding in children

4. It occurs during late diastole when the atria contracts

The correct answer is: It occurs during late diastole when the atria contracts

The fourth heart sound (S4) is associated with late diastole and occurs when the atria contract, leading to the flow of blood into the ventricles. This sound is produced due to the vibrations of the cardiac muscle and surrounding structures as the atria forcefully contract to fill the ventricles, especially when there is a stiff or hypertrophied left ventricle. This sound is significant as it may indicate underlying cardiac conditions, such as left ventricular hypertrophy or decreased ventricular compliance, but it can also be a normal finding in certain populations, particularly in older adults. The timing during late diastole is crucial because it reflects the filling phase just before ventricular contraction, making it an important aspect of heart sound interpretation in clinical settings. Additional options mention aspects unrelated to the true nature of S4. The sound does not occur after ventricular contraction; rather, it precedes the first heart sound (S1) associated with ventricular contraction. It is not specifically best heard with the diaphragm of the stethoscope, as S4 is typically best appreciated with the bell of the stethoscope to capture the low-frequency sounds. Lastly, while S4 can be auscultated in children, it is not regarded as a normal finding