The timing of a murmur is crucial to accurate diagnosis. A murmur is either systolic, diastolic or continuous throughout systole and diastole. Remember that systole occurs between the S1 and S2 ...

The murmur of a patent ductus arteriosus is continuous throughout systole and diastole. Often the S2 heart sound is difficult to detect. The murmur begins just after S1 and crescendos, peaks at S2 ...