What are the physical examination findings associated with a left atrial myxoma?

Physical Examination Findings in Left Atrial Myxoma

Left atrial myxoma classically presents with a triad of findings on physical examination: cardiac auscultatory abnormalities (particularly a diastolic rumbling murmur mimicking mitral stenosis with or without a "tumor plop"), signs of systemic embolization, and constitutional symptoms, though many patients may present with only one or two components of this triad. 1, 2, 3

Cardiac Auscultatory Findings

Diastolic Murmurs

• A middiastolic or presystolic rumbling murmur at the apex is the most common auscultatory finding, present in approximately 53.5% of cases, mimicking mitral stenosis due to mechanical obstruction of the mitral valve orifice during diastolic filling 1, 3, 4
• The murmur is positional and may vary with changes in body position because the pedunculated tumor moves with gravity and blood flow, intermittently obstructing the mitral valve 2, 3
• The opening snap of mitral stenosis is characteristically absent in isolated left atrial myxoma, helping to distinguish it from true valvular mitral stenosis 1, 5

Tumor Plop

• An early diastolic sound ("tumor plop") occurs in approximately 15% of cases, representing the tumor striking the mitral valve apparatus or ventricular wall during early diastole 3, 4
• This sound is lower-pitched and occurs slightly later than a mitral opening snap, typically 80-120 milliseconds after the second heart sound 3

Systolic Murmurs

• A systolic ejection murmur may be present in some cases, particularly when there is associated mitral regurgitation from valve damage or incomplete leaflet coaptation 3, 5, 6

Signs of Cardiac Obstruction and Heart Failure

Left Atrial and Ventricular Findings

• Signs of left-sided heart failure including pulmonary congestion with rales, elevated jugular venous pressure, and peripheral edema may be present in 67% of patients with obstructive symptoms 3, 4, 7
• Orthostatic hypotension has been reported as an unusual presenting sign when the tumor causes positional obstruction of cardiac output 6

Electrocardiographic Correlates

• Left atrial enlargement is the most frequent ECG finding, present in approximately 35% of cases, reflecting chronic left atrial pressure elevation 3
• Arrhythmias are relatively uncommon despite the left atrial mass 3

Embolic Manifestations

Neurological Signs

• Focal neurological deficits from embolic stroke occur in 29% of cases and may be the presenting manifestation, particularly in younger male patients who have statistically higher embolic risk 2, 3, 8
• Transient ischemic attacks or stroke result from embolization of either tumor fragments or thrombus formed on the friable tumor surface, with villous or papillary surface morphology conferring markedly higher embolic risk 2, 3

Peripheral Embolic Signs

• Digital ischemia, livedo reticularis, or other signs of peripheral embolization may occur, occasionally mimicking systemic vasculitis 9
• Painful or painless peripheral neuropathy from embolic events to vasa nervorum has been reported 9

Constitutional and Systemic Findings

General Appearance

• Cardiac cachexia and weight loss may be prominent, particularly in elderly patients with chronic obstruction 3, 5
• Fever is present in approximately 34% of cases, related to interleukin-6 secretion by the tumor 3

Laboratory-Associated Physical Findings

• Signs mimicking connective tissue disease or systemic vasculitis including arthralgias, myalgias, and Raynaud's phenomenon may occur, more commonly in female patients 3, 9
• These constitutional symptoms can lead to misdiagnosis as inflammatory or rheumatologic conditions 9

Key Clinical Correlations

Tumor Size and Physical Findings

• Larger tumors (mean weight 37 g, range 15-180 g) are significantly more likely to produce cardiac symptoms, pseudo-mitral auscultation signs, tumor plop, and ECG/radiologic evidence of left atrial hypertrophy and dilatation 3
• Tumors with friable or villous surfaces (35% of cases) are significantly associated with embolic presentations rather than obstructive cardiac symptoms 3

Age and Sex Patterns

• Younger and male patients more commonly present with neurological embolic symptoms 3
• Female patients more frequently present with systemic constitutional symptoms 3
• The typical age range is 5-84 years with a female predominance (approximately 2:1 ratio) 3

Critical Diagnostic Pitfalls

Absence of Classic Findings

• Up to 36% of patients may have no cardiac auscultation abnormalities, making physical examination alone insufficient to exclude the diagnosis 3
• Murmurs may be soft (grade 1/6) or intermittent, and careful auscultation in multiple positions is essential 6
• The tumor plop is present in only 15% of cases, so its absence does not exclude myxoma 3

Mimicry of Other Conditions

• The combination of diastolic murmur, constitutional symptoms, and elevated inflammatory markers can mimic infective endocarditis, requiring echocardiography to differentiate 2, 9
• Systemic symptoms with elevated complement levels and anti-DNA antibodies may lead to misdiagnosis as systemic lupus erythematosus or other vasculitides 9

Examination Technique

• Dynamic auscultation with positional changes (supine, left lateral decubitus, sitting, standing) may reveal or accentuate murmurs that are otherwise inaudible 1
• Careful serial examinations are important, as one case report documented that a heart murmur was not appreciated despite frequent observation over 8 months 9