Base Left: Continuous Murmur

A pan diastolic murmur begins with the second sound and extends throughout the diastolic period. It is usually produced as a result of one of four mechanisms:

• Abnormal communication between the aorta and the right side of the heart or with the left atrium
• Abnormal communication between an artery and a vein
• Abnormal increase in flow or constriction in an artery
• Increased or turbulent blood flow through veins

Patent ductus arteriosus (PDA) is a classical example of this murmur. This condition is usually corrected in childhood. It is heard best at base left and has both a systolic and diastolic component. It is known as a continuous murmur. It is heard best with the bell.

The sound you heard is an example of a continuous murmur.