2025 CCRN Practice Test – Complete Study Resource

The opening snap is associated with the rapid filling phase of the ventricles, which occurs during early diastole. This sound is typically a result of the abrupt opening of a stenotic mitral valve, allowing blood to flow from the left atrium into the left ventricle. During early diastole, the pressures in the left atrium are higher than in the left ventricle, leading to the swift movement of blood that generates the opening snap as the valve opens.

Understanding the phases of the cardiac cycle is crucial for identifying various heart sounds and their clinical significance. In early diastole, the heart transitions from a contraction phase (systole) into a relaxation period, which allows for the chambers to fill with blood. Therefore, the occurrence of the opening snap specifically during this phase signifies that there is likely an abnormality at the mitral valve level, highlighting its importance in clinical assessment.