The next step in the evaluation of our patient is auscultation. Before moving on to our patient's case, we recommend a review of murmur classification.
You may now choose to complete the review module, or murmur classification, or proceed to our patient's case.
Normal (laminar) vs. turbulent flow
Laminar, or streamlined blood flow, is silent. All murmurs represent turbulence as blood flows through the heart or blood vessels. Turbulence results when flow velocity exceeds that which allows flow to be laminar. This occurs frequently in normal infants and children, in whom energetic ventricular contraction produces high ejection flow velocity. Turbulence also can result from increased cardiac output, as in fever; or narrowing of a flow channel, as in a stenotic valve.
On way to demonstrate this is to compare the sound that you hear when water passes through a garden hose. When the hose is straight, flow is streamlined and there is little sound. When the hose is kinked, flow becomes turbulent and noisy. Let us watch and listen together.