Tumor Plop (Left Atrial Myxoma)
A large left atrial myxoma produces a diastolic sound that is referred to as a tumor plop. This sound arises from obstruction to ventricular in-flow that occurs as the tumor comes to rest over the mitral annulus. It is the functional equivalent of mitral valve stenosis and may be associated with a low frequency diastolic murmur. Over time, damage to the mitral valve may occur, resulting in a concurrent regurgitant murmur. Although similar in timing to mitral valve stenosis, the tumor plop differs from the mitral opening snap in that it is a low frequency sound and is thus heard best with the bell.
Diagnosing atrial myxoma is similar to diagnosing the pericardial knock. It is as much about the company it keeps as it is about the characteristics of the sounds you hear. Atrial myxoma is slightly more common in women and there is generally no prior history of rheumatic fever. Patients may present with dyspnea, orthopnea, palpitation, fever, and embolic phenomenon. An abnormal ANA may be seen in conjunction with atrial myxoma.
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Updated March 2011