From the Guidelines
Auscultation for left atrial myxoma should focus on identifying the characteristic "tumor plop" sound and associated murmurs that occur as the tumor moves within the left atrium, as diagnosed by echocardiography 1. When examining a patient with suspected left atrial myxoma, position them in the left lateral decubitus position and listen carefully at the apex of the heart (mitral area) using the bell of the stethoscope. The classic finding is a low-pitched early diastolic sound called the "tumor plop," which occurs when the myxoma prolapses through the mitral valve during diastole. This sound is distinct from an S3 gallop as it occurs slightly later and has a different quality. You may also hear a diastolic murmur similar to mitral stenosis as the tumor obstructs blood flow from the left atrium to the left ventricle. The intensity of these sounds often varies with position changes, becoming more prominent when the patient sits up or stands, which helps differentiate it from other cardiac conditions. Additionally, listen for an accentuated S1 and potential systolic murmurs if the tumor causes mitral regurgitation. These auscultatory findings are often intermittent and may change with the patient's position due to the mobile nature of the tumor, making careful and thorough examination essential for detection, as cardiac auscultation remains the most widely used method of screening for valvular heart disease (VHD) 1. Some key points to consider when auscultating for left atrial myxoma include:
- Positioning the patient in the left lateral decubitus position to optimize sound transmission
- Using the bell of the stethoscope to listen for low-pitched sounds
- Listening carefully for the "tumor plop" sound and associated murmurs
- Varying the patient's position to assess changes in sound intensity and characteristics
- Considering the use of echocardiography to confirm the diagnosis, as it is particularly useful in diagnosing left atrial thrombus, aortic atheroma, prosthetic valve abnormalities, native valve disease, and other structural abnormalities of the heart 1.
From the Research
Auscultation Techniques for Diagnosing Left Atrial Myxoma
- Cardiac auscultation abnormalities are present in 64% of patients with left atrial myxoma, with pseudo-mitral valve disease being the most common finding (53.5%) 2
- The "tumor plop" is a suggestive auscultation sign, although it is less common (15%) 2
- Auscultation findings may include signs of mitral valve obstruction, such as a diastolic murmur 2
- A thorough cardiac examination, including auscultation, is essential for diagnosing left atrial myxoma, as it can help identify patients with cardiac symptoms and signs of mitral valve obstruction 2
Diagnostic Approaches
- Echocardiography is a non-invasive diagnostic procedure that can help diagnose left atrial myxoma, and it has become the primary diagnostic tool since its introduction in 1977 2
- Other diagnostic approaches, such as angiocardiography and coronary angiography, may be used in certain cases, especially in older patients who are at risk for coronary artery disease 3
- A combination of physical examination, echocardiography, and other diagnostic tests can help establish a diagnosis of left atrial myxoma 4, 5, 6
Clinical Presentation
- Patients with left atrial myxoma may present with a variety of symptoms, including congestive heart failure, dyspnea, arrhythmias, chest pain, and syncope 3
- Embolic complications can occur, especially in patients with a friable or villous tumor surface 2
- Constitutional symptoms, such as fever, weight loss, and symptoms resembling connective tissue disease, can also occur due to cytokine secretion 2