Interpretation of heart murmurs in the field

A murmur is a sound associated with the cardiac cycle and generated by turbulent blood flow. The cause of the turbulent follow is useful to explain the pathophysiology of the murmur. There are three main broad reasons for turbulent flows: regurgitation, stenosis and shunts. A relevant group of murmurs in horses are the “physiologic murmurs”, ejection or flow murmurs. Physiopathologically, it is useful to place these under the stenosis category. These physiologic murmurs are not generated by stenosis but are mainly caused by ejection of blood through a major vessel and therefore sound similar to stenosis of a major vessel. The objective of this manuscript is to give an easy -to-follow mental chart for field practitioners that have to interpret heart murmurs using their stethoscopes and their hands. This manuscript is a logical place to start for young clinicians and students and a refresher or useful tool to explain the problem to owners for experienced clinicians.