A cardiology stethoscope is a specially designed stethoscope for use by doctors and nurses in the fields of cardiology and cardiovascular surgery. Its design allows for a greater ability to hear both low and high frequency sounds, necessary as those in this discipline study the heart and need to hear even the pumping of liquid blood through the four chambers and four valves of the heart. A regular stethoscope is designed to allow a user to listen to the inner working of the body, such as a heartbeat, a pulse in an extremity, a bowel sound or fluid in the lungs. A cardiology stethoscope allows the user to listen for and identify specific heart sounds such as clicks, murmurs and rubs.
Design, performance and quality separate a regular stethoscope from a cardiology stethoscope. As compared to a regular stethoscope, a cardiology stethoscope has a thicker and much shorter tube between the earpieces and the diaphragm, the round knob at the end of this instrument. This shorter distance for sound to travel and the thicker tubing for improved transmission allow a user to auscultate, or listen for, a wider variety of body sounds. The shorter tubing of this type of stethoscope also avoids a problem common to regular stethoscopes of longer length: the interference of clear auscultation caused by the rubbing of the curled tubing against itself as it loops if not pulled taut.
A cardiology stethoscope also has a heavier and better-designed headset that is usually more comfortable to use than a regular stethoscope. Earplugs are larger and thicker to seal out ambient noise during auscultation. The round diaphragm is usually made of stainless steel as opposed to a regular stethoscope's plastic diaphragm. These design features also work to improve sound transmission and quality of cardiology acoustics.
The acoustics of cardiology are often subtle and take a great deal of time and practice to master. In addition to the da-dum of every heartbeat — formally referred to as S1 and S2 — there are other sounds such as murmurs, clicks and rubs. The commonly known term heart murmur refers to an actual sound heard when valves don't work correctly and blood leakage is audible with use of a cardiology stethoscope. The degree of auscultation capable by a trained healthcare worker using this type of equipment allows murmurs to be graded along a continuum from one to four.
Cardiology stethoscopes are expensive. The purchase price for one averages around $160 US Dollars (USD) while an inexpensive stethoscope can be purchased for as little as $10 USD. Name engraving on the stainless steel diaphragm is often offered for this type of stethoscope in order to prevent intentional theft or even unintentional mix-ups between similar looking instruments.