Two-dimensional Speckle Tracking Echocardiography and Three-dimensional Echocardiography Characterization of Left Atrial Giant Myxoma.

Myxomas are the most common cancerous nonneoplasms among the rare heart's tumors. Usually, they are located in the left atrium (LA). They are more frequent in women than in men and ranged in age from 30 to 50 years. Rarely, myxoma is completely asymptomatic and in that case represents a fortuitous discovery. However, usually, it is characterized by several symptoms as fatigue, dyspnea, chest pain, dizziness, cough, and sometimes, by sudden death. We refer on a case of LA myxoma found in a woman without symptoms but having a systolic precordial murmur. Two-dimensional echocardiography (2-DE) shown an unknown giant LA myxoma, almost completely occupying the atrial cavity. 2-D left atrial longitudinal speckle tracking echocardiography first allowed to note the changes in the percentage of "reservoir," "conduit," and "booster pump" phases of the left atrial function respect to normal subjects, revealing LA dysfunction. Three-dimensional echocardiography (3-DE) shown left atrial mass and its attachment to the atrial septum better than 2-DE. Furthermore, 3-DE allowed to define the shape of LA myxoma and its 3-D, irregular contour.

INTRODUCTION

Myxoma is a most common, benign heart neoplasm.[1] About 75% of myxomas are located in the left atrium (LA); they require a surgical removal to avoid the clots formation and sudden obstruction of mitral orifice. Myxomas are more frequent in women than in men, and their symptoms fluctuate from the absence of any illness to palpitations, fatigue, dyspnea on exertion (until pulmonary edema), dizziness, shortness of breath, and sudden death.[2] Diagnosis of myxoma is commonly based on echocardiography. Particularly, 2-D echocardiography (2-DE) is the noninvasive diagnostic technique for detecting intracardiac masses. However, it is limited by planar imaging, which provides a true visualization of symmetric structures; in addition, it is unable to detect the shape, the depth, and the three-dimensional structure of intracardiac masses. In addition, 2-DE does not allow the morphology of intracardiac pressures at different phases of the cardiac cycle.[3] On the contrary, 2-D left atrial longitudinal speckle tracking echocardiography (2-D-LASTE), and 3-D echocardiography (3-DE) are a relatively new ultrasonic techniques that allow to go beyond these limitations.

CASE REPORT

A 48-year-old woman with precordial holosystolic murmur was admitted to Ambulatory of Echocardiography of our Department. Arterial pressure was 120/80 mmHg. A 12-lead electrocardiogram showed sinus rhythm at 55 beats/min, left axial deviation, and normal ST-T tract. Pulses were present both at upper and lower limbs. Afterward, transthoracic echocardiography was performed. 2-DE showed both ventricular cavities of normal dimensions, with preserved ejection fraction % of left ventricle (LV) (60%), and tenuous pericardial effusion (most evident on LV posterior wall). From apical four chambers approach, a large mass occupying LA cavity was seen [Figure 1]. This measured 3.92 cm × 4.70 cm and was attached to the inferior part of the interatrial septum. 2-D-color Doppler showed a regurgitant jet across the mitral limbs during systole, going around the left atrial mass [Figure 2]. Furthermore, both light diastolic aortic and pulmonary regurgitation were recorded. Longitudinal 2-D-LASTE and 3-DE were also performed. By these techniques, intra-atrial pressures during the different phases of cardiac cycle [Figure 3] and 3-D shape of LA mass [Figure 4] were, respectively, recorded. The form of LA myxoma only was also obtained by 3-DE [Figure 5]. Subsequently, LA mass was promptly removed surgically.

Figure 1

2-D Ecocardiography recorded from parasternal long-axis view-Voluminous myxoma measuring 3,92 × 4,70 cm. Occupying left atrial cavity. An evident pericardial effusion is seen on the posterior wall of LV

Figure 2

2-D Echocardiography-Systolic regurgitation by mitral limbs passing along the lateral contour of LA myxoma

Figure 3

Longitudinal speckle tracking echocardiography recorded in patient with left atrial myxoma-Decrease of reservoir and increase of conduit and booster pump phases of LA function

Figure 4

3-D Echocardiography recorded from parasternal long-axis approach-Giant myxoma attached to the atrial septum, nearly completely taking LA cavity

Figure 5

3-DE-At down on the rigth is evident tridimensional morfology, shape and irregular contours of LA giant myxoma extrapolated from LA cavity

DISCUSSION

Myxomas are cardiac benign tumors usually located in the right or the LA, attached to the interatrial septum. Tumor is 3 times more common in females than in males and generally occurs between the third and sixth decades.[4] LA myxoma (more frequent than right) may be completely asymptomatic until growing, it obstructs the mitral valve with sudden death. In about 30–40% may produce cerebral emboli and can be responsible for syncope.[5] Myxomas also produce vascular endothelial growth factor, which contributes to the induction of angiogenesis and tumor growth.[6] A large LA myxoma can induce a sudden obstruction of atrioventricular orifice, miming mitral valve stenosis. This condition can be cause of syncope as previously described.[7]

Habitually, the diagnosis is readily established by 2-DE that may be considered the gold standard for the diagnosis of LA myxoma, with a sensitivity of 95% and a sensitivity of nearly 100%.[8] Nevertheless, 2-DE can visualize the intra-atrial mass, its dimensions and attachment to the atrial walls but are unable to define the changes of intra-atrial pressures dependent on LA dysfunction and as a consequence, the different contribution of reservoir, conduit, and booster pump to LA emptying and LV filling respect to the normal LA. In this report, longitudinal-2-D-LASTE shown a reduced “reservoir” phase, whereas the “conduit” and “booster pump” phases were increased. This picture depends on the different contribution to pressures of LA cavity engaged by myxoma.[9] Particularly, the expansion index (reservoir) is reduced because the mass already fills LA cavity. On the contrary, the passive emptying fraction (conduit) and the active emptying fraction (booster pump) are increased for overcome the increase intra-atrial pressure related to the presence of myxoma.[10] 3-DE confirmed the attachment of tumor to inferior segment of interatrial septum and allowed to obtain depth, 3-D shape contour of myxoma only, isolated from LA cavity.[11] Conclusively, longitudinal-2-D-LASTE allowed to define the changes of LA function myxoma-related. In addition using 3-DE, we first recorded 3-D appearance of myxoma only, not included in LA cavity.

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Conflicts of interest

There are no conflicts of interest.