What condition is indicated by a "machinery" like murmur?

A "machinery" like murmur is characteristically associated with patent ductus arteriosus (PDA). This murmur arises from the continuous flow of blood through the ductus arteriosus, a vessel that connects the pulmonary artery to the descending aorta, which is persistent in this condition.

In PDA, the murmur typically has a "machine-like" quality because it occurs throughout the cardiac cycle—meaning it can be heard during both systole and diastole. This is distinctly different from other murmurs, which may be more isolated to specific phases of the heartbeat.

In contrast, conditions like mitral regurgitation, aortic stenosis, and tricuspid regurgitation tend to produce different types of murmurs that do not have this continuous nature. They are usually systolic or diastolic murmurs with varying characteristics based on the specific pathophysiology involved. Therefore, recognizing the unique sound and timing of the murmur in PDA is crucial for accurate diagnosis and understanding the underlying condition.