Abstract 11708: Giant Myxoma Causing Severe Pulmonary Hypertension

Abstract

Introduction: Myxomas are the most common primary cardiac tumor, with clinical manifestations depending on tumor size and location. We present a case of giant left atrial (LA) myxoma causing functional mitral stenosis and associated severe pulmonary hypertension. Case: A 75-year-old woman with newly diagnosed heart failure and atrial fibrillation presented to the emergency department with 2-months of chest pain and shortness of breath. She had left-sided chest pain during exertion and at rest, dyspnea, and 3-pillow orthopnea. She was normothermic, blood pressure of 93/57 mm Hg, HR 63 bpm, respiratory rate of 21, and 91% oxygen saturation on room air. Cardiovascular exam revealed no murmurs, elevated JVD and bilateral lower extremity edema. Chest CT revealed a large mass, measuring 9x4 cm, in the LA extending into the left ventricle. TTE demonstrated a large mobile mass in the LA measuring 9.4x3.9 cm. The mass extended through the mitral valve into the left ventricle, causing functional mitral stenosis with mean inflow gradient of 10 mmHg. Severe tricuspid regurgitation was demonstrated with a peak regurgitant velocity of 4.89 m/s, with estimated right ventricular systolic pressure of 101 mmHg. Pre-operative pulmonary artery systolic pressure was 100 mmHg. She underwent surgical excision. Histology confirmed diagnosis of myxoma, and the mass measured 7.2 x 5.0 x 4.7 cm. At follow up, she had no heart failure symptoms or additional episodes of atrial fibrillation. Repeat TTE demonstrated normal RVSP. Discussion: Symptoms of myxoma include cardiovascular, embolic and constitutional symptoms. While obstructive symptoms are common in large myxomas, only 10% have severe functional mitral stenosis. Despite this, sequela of pulmonary hypertension and tricuspid regurgitation is not well documented. Diagnosis is made by TTE, which also allows assessment of valvular and hemodynamic changes. Treatment requires surgical resection, with low rates of recurrence.