MioAtlas
G9: Masses and tumors

Left atrial myxoma

Most frequent primary benign cardiac neoplasm in adults, located predominantly in left atrium and attached by a mobile stalk to interatrial septum at fossa ovalis.

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Definition

Most frequent primary benign cardiac neoplasm in adults, located predominantly in left atrium and attached by a mobile stalk to interatrial septum at fossa ovalis; during diastole it prolapses through mitral orifice into left ventricle producing intermittent mechanical obstruction to ventricular filling ('pseudotumoral functional mitral stenosis') and retrograde venocapillary hypertension [C10] [G810-07].

Severity criteria

  • Literal statement from Reynen classic review [G810-07, Abstract]:
    • «Although cardiac myxomas are histologically benign, they may be lethal because of their strategic position»
    • «Myxomas must therefore be included in the differential diagnosis of valvular heart disease, cardiac insufficiency, cardiomegaly»
  • Mild (L): Small mass with mean transmitral gradient < 5 mmHg; minimal prolapse [C10] [G1-01].
  • Moderate (M): Partial occupation of mitral orifice; mean transmitral gradient 5–10 mmHg [C10] [G1-01].
  • Severe (G): Large obstructive mass widely occluding mitral orifice in diastole; mean transmitral gradient > 10 mmHg; pulmonary venocapillary hypertension and compromised cardiac output [C10] [G1-01].

Findings by layer

Hemodynamics

  • Mean transmitral gradient: L < 5 mmHg, M 5–10 mmHg, G > 10 mmHg [C10] [G1-01].
  • Mean pulmonary capillary wedge pressure: L < 12 mmHg, M 15–20 mmHg, G > 20 mmHg [C10].
  • Cardiac output: preserved in L; decreased in G (< 3.8 L/min) [C10].

Rhythm

  • Normal sinus rhythm [C10] [G810-07]; in long-standing disease with marked left atrial dilation, atrial fibrillation may be observed [E2].

ECG

  • Left atrial enlargement with broad, notched P wave in lead II and terminal negative component in V1 (P mitrale wave) in sinus rhythm [E1].

Heart sounds and murmurs

  • Tumor plop: Early/mid-diastolic sound (tumor snap ('tumor plop')) audible at apex after second heart sound (S2), later than mitral opening snap, produced by sudden deceleration of mobile tumor mass as it prolapses into left ventricle [G810-07].
  • Diastolic rumble: Apical mid-diastolic murmur that characteristically changes intensity with alterations in patient position [G810-07] [B1].
  • First heart sound (S1): Accentuated, loud S1 [G810-07].

Arterial pulse

  • Physiological in L and M grades; reduced volume pulse (parvus) in obstructive G grade [B4].

Jugular venous pulse

  • Habitually normal; in grade G with retrograde pulmonary hypertension, increased venous pressure and prominent 'a' wave [B3].

Maneuvers

  • Postural change: Typical positional variation of auscultatory findings (murmur and tumor plop vary according to gravity and stalk orientation) [G810-07] [B1].
  • Valsalva maneuver: Decreases venous return and attenuates diastolic murmur [B1].

Simulator severity grades

Simulator severity grades: Mild, Moderate, Severe
Baseline rhythm: Normal Sinus Rhythm

Also known as: Left atrial myxoma · Atrial myxoma · Left atrium myxoma · Cardiac myxoma

Other pathologies in this group

Sources

  1. [B1] Bedside diagnosis of systolic murmurs . N Engl J Med (1988) . DOI: 10.1056/NEJM198806163182404 PubMed: 2897627
  2. [B3] The jugular venous pressure revisited . Cleve Clin J Med (2013) . DOI: 10.3949/ccjm.80a.13039 PubMed: 24085809
  3. [B4] The Carotid Pulse . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250154
  4. [C10] Primary Cardiac Tumors: JACC: CardioOncology State-of-the-Art Review . JACC CardioOncol (2020) . DOI: 10.1016/j.jaccao.2020.05.009 PubMed: 34396236
  5. [E1] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191097 PubMed: 19228820
  6. [E2] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191095 PubMed: 19228822
  7. [G1-01] Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice . J Am Soc Echocardiogr (2009) . DOI: 10.1016/j.echo.2008.11.029 PubMed: 19130998
  8. [G810-07] Cardiac myxomas . N Engl J Med (1995) . DOI: 10.1056/NEJM199512143332407 PubMed: 7477198