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:
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.