Cardiac masses are rare and have a wide range of clinical presentations depending on their location, which makes their diagnosis challenging. Cardiac masses can be primary or secondary depending on their origin, and further categorized as benign and malignant. Secondary, or metastatic tumors to the heart, are more common than primary cardiac tumors. Approximately 90% of primary cardiac masses are benign with the remaining 10% malignant. Myxomas are the most common benign cardiac mass and account for approximately half of all benign cardiac tumors [1]. Myxomas are most often found during the fourth to sixth decades of life, with a female predominance. The most common location of myxomas is the left atrium where they are found approximately 75% of the time. Less commonly, they may arise from the right atrium approximately 20% of the time, and around 5% of them are found in the ventricles [2]. The size, location, risk of embolic event, and involvement of other cardiac structures, are all factors that contribute to the wide range of presentation for cardiac myxomas. Patients with myxomas may remain asymptomatic, while others may report symptoms such as fatigue and fever, dyspnea, and syncope. Arrhythmias are uncommon with myxomas [3]. Here we present an unusual case of a 67-year-old man presenting with pre-syncope and symptomatic bradycardia due to a large left atrial myxoma.
Case presentation
A 67-year-old male with chronic obstructive pulmonary disease (COPD), hypothyroidism, and asymptomatic sinus bradycardia, presented to the emergency department (ED) after experiencing a pre-syncopal episode. Earlier that week the patient developed sudden onset dizziness and light headedness while at dinner. Similar episodes over the past year were reported with worsening night sweats for several weeks. He denied headaches, vertigo, chest pain, shortness of breath, nausea, changes in vision or focal neurologic deficits. The lightheadedness lasted for about 30 s and then self-resolved, but he experienced persistent fatigue for a few hours afterwards. Prior to the episode of dizziness, he denied any notable changes with body position, flushing of the face/body, anxiety, and was not wearing any tight-fitting clothes. An electrocardiogram (ECG) showed sinus bradycardia and referred him to the emergency department for further evaluation.
In the emergency department, he was afebrile with a regular pulse of 39 bpm, blood pressure of 161/81, respiratory rate 18, and oxygen saturation was within normal limits on room air. Blood work was unremarkable. ECG showed sinus bradycardia, notched p-waves in limb lead II, and peaked T-waves in precordial leads V3, V4 and V5 with no evidence of heart block or ischemic changes (Fig. 1a). Chest x-ray showed no acute intrathoracic pathology, vascular congestion or pulmonary edema, but revealed a double density at the right heart border, consistent with left atrial enlargement. Physical exam revealed a regular heart rhythm without murmurs. Heart rate (HR) demonstrated an appropriate chronotropic response increasing from 40 to 60 s after 2 min of physical activity. No jugular venous distension or extremity edema was noted. The lungs were clear without rales or crackles. Neurological exam did not reveal any focal deficits, both motor and sensory function were intact bilaterally.
Transthoracic echocardiogram (TTE) showed a Left Ventricular Ejection Fraction (LVEF) of 60–65%, a positive bubble study and a mass in the left atrium estimated to be 3 cm × 4.8 cm, that was observed obstructing the mitral valve during diastole (Fig. 2a, b). The mass was a mobile, hyperechoic structure in the left atrium suggestive of cardiac myxoma or thrombus. Transthoracic echo further characterized the heterogeneous hyperechoic mass, showing hypoechogenic areas representing space neighboring the stalk (Fig. 3a). Definity enhanced contrast imaging of the myxoma similarly showed a heterogeneous mass which is representative of the mass’s vascularity, a characteristic finding which can help differentiate myxomas from thrombi, which tend to have a more homogeneous echogenicity (Fig. 3b).
Outcome and follow-up
After the diagnosis of left atrial myxoma was made the patient was referred for surgical resection. Prior to surgery, coronary angiography demonstrated no significant coronary artery disease but did demonstrate tumor blushing consistent with myxoma. The patient then underwent left atrial mass resection and patent foramen ovale (PFO) repair. In the operating room, the atrial tumor was a large, solid, friable semi-mobile mass with a wide base stalk adherent to the left atrial septum, approximately 5.5 × 5.1 × 3 cm. The procedure was completed without any intraoperative complications. The gross specimen was dark-tan and red, with irregular borders and overall smooth surfaces (Fig. 4). The patient had an uncomplicated post-operative course and was discharged on post-op day 4. Interestingly upon follow-up one month after the myxoma was resected, the patient denied any additional pre-syncopal episodes and his bradycardia had resolved. Heart rate was 69 bpm 3 months after resection (Fig. 1b).
