S Kanaan, I Nuno
asthma, atrial myxoma
S Kanaan, I Nuno. Atrial Myxoma Presenting as Asthma in Adolescent. The Internet Journal of Thoracic and Cardiovascular Surgery. 2006 Volume 8 Number 2.
This case report focuses on a 15 year old female who was initially diagnosed with asthma and treated as such for six months. It illustrates the importance of taking a detailed history, and performing a thorough physical exam to aid in establishing a diagnosis. This case emphasizes that in young patients who present with new onset asthma, one should include atrial myxoma in the differential diagnosis. A heart murmur on exam and an echocardiogram should establish the diagnosis and allow operative intervention in a timely fashion. There are only two citations in the literature regarding patients who were diagnosed with asthma and were found to have an atrial myxoma. It certainly is an uncommon presentation for mxyoma but it is imperative that it remains in the differential diagnosis so treatment is not unnecessarily delayed.
The patient is a 15 year-old Hispanic female who was in her usual state of health and began to have exercise intolerance at school followed by fatigue and shortness of breath. She saw her primary physician who diagnosed her with asthma based upon her symptoms and wheezing on auscultation. She was treated with an albuterol inhaler. She continued to have symptoms for six months and her exercise intolerance and shortness of breath worsened. She returned to her primary physician with a new productive cough and despite a course of antibiotics, she did not improve. She did not have any fevers or weight loss. She had no other significant past medical history and was taking only an albuterol inhaler.
On physical exam, her vitals signs were blood pressure of 113/72, heart rate of 102, temperature of 98.0F, and a respiratory rate of 20. On physical exam, she had no jugular venous distention, her lungs were clear to auscultation with no crackles and no wheezing, and her heart was regular rhythm with a systolic murmur heard over the right sternal border. Her abdomen was soft, non-tender, non-distended, and she had no peripheral edema.
Her laboratory values were all within normal limits. A chest x-ray showed a small right pleural effusion. On echocardiogram, she had a 7.5cm x 3.5cm x 3.5cm (Figure 1) mass arising from the atrial septum in the right atrium prolapsing through the tricuspid valve consistent with a right atrial myxoma. She was admitted to the surgical service and prepared for the operating room.
In the operating room, she had a median sternotomy followed by bicaval cannulation and placement on cardiopulmonary bypass. The right atrium was opened and an 8cm x 4cm mass attached by a stalk to the lateral right atrial wall superior to inferior vena cava orifice was identified. The mass was resected and a DeVega tricuspid valve annuloplasty was performed to alleviate the tricuspid regurgitation. The atrium was closed, and the patient was successfully weaned off bypass and returned to the intensive care unit. Her final pathology was an 8cm x 6cm x 3cm hemorrhagic atrial myxoma, with a one cm stalk weighing 33grams.
Postoperatively, she was extubated on postoperative day one, and transferred to the step-down unit on postoperative day two. Her chest tubes were removed and she was discharged home on postoperative day four. In follow-up, she is asymptomatic and remains in good health.
Primary tumors of the heart are uncommon with an incidence ranging between 0.17% and 0.19%.1 Approximately 75% of primary cardiac tumors are benign and 25% are malignant, with myxoma accounting for 50% of the benign tumors.2 Most myxomas occur sporadically, are more common in women, present between the third and sixth decades of life, and are solitary 94% of the time.1,3 Myxomas occur in any chamber of the heart but usually originate in the left atrium (75%) (3). The next most frequent site is the right atrium (10%–20%) followed by the right and left ventricle (6% to 8% each).1,4
Approximately 5% of myxomas demonstrate a familial autosomal dominant pattern. These patients have an abnormal DNA genotype chromosomal pattern and they in contrast to the sporadic form occur in patients that are younger, occur equally in males and females, have higher recurrence rates (21-67%), and over 20% have mutlicentric tumors.5,6,7,8,9
Atrial myxomas usually originate from the interatrial septum but can arise from cardiac valves, the atrial appendage, the pulmonary artery or vein, and the superior or inferior vena cava.1,10 Right sided atrial myxomas are typically broad based in their attachments and are more likely to be calcified compared to left sided lesions.11 Right ventricular myxomas originate from the free wall and left sided lesions arise near the posterior papillary muscle.2
Grossly, most myxomas are smooth, polypoid, pedunculated, mobile and not likely to fragment. Average size is 5cm and they appear to grow rapidly with a mean weight of 50-60grams.3,12Histologically, myxomas typically have polygonal shaped nest of cells and contain smooth muscle cells, areas of hemorrhage and calcification, macrophages and chronic inflammatory cells.1,2
The classic presentation of myxoma includes intracardiac obstruction with congestive heart failure (67%), signs of embolization (30-40%), and constitutional symptoms that can include fever (19%) or weight loss and fatigue (17%), myalgia, weakness, and arthralgia (5%).2,3 The most common cause of acute presentation is from obstruction of blood flow in the heart. Myxomas in the left atrium cause dyspnea and heart failure with elevated pulmonary pressures. Syncope can occur from temporary occlusion of the mitral valve. Right atrial myxomas also present in heart failure with venous hypertension, hepatomegaly, ascites, and peripheral edema. Ventricular myxomas can also obstruct ventricular outflow.
The second most common presentation of myxoma is systemic embolization, occurring in 30-40% of patients.1,2 Left atrial myxomas lead to 50% of these embolic episodes with neurologic deficits ranging from TIA's to strokes, seizures, intracranial aneurysms and brain necrosis.13,14,15 Left sided myxomas can also cause lower extremity, abdominal viscera, renal, and coronary ischemia.16,17 Emboli of right-sided myxomatous can obstruct pulmonary arteries, cause pulmonary hypertension and even cause death from acute obstruction.1
Left atrial myxomas may produce auscultatory findings similar to mitral stenosis. The well-described “tumor plop” is an early diagnostic sound heard may be interpreted as a third heart sound. Right atrial myxomas may produce the same findings with the exception that they are best heard along the lower right sternal border versus the cardiac apex.
Chest x-ray may demonstrate cardiomegaly, pulmonary venous congestion, and possibly calcification of tumor within the cardiac silhouette. The majority of myxoma patients though with have a normal chest x-ray.1Echocardiography is the most useful test for the diagnosis of myxomas. The sensitivity of echocardiography for myxoma is 100% and this has largely replaced angiography.18In addition, transesophageal echocardiogram can reveal tumor size, location, mobility and attachment.19 CT scan and MRI have been employed in diagnosing myxomas.20 MRI is particularly useful in the evaluation of ventricular mxyomas, but echocardiography remains the best diagnostic modality.
Surgical resection is the only effective therapeutic option for patients with cardiac myxoma and should not be delayed since death from obstruction to flow or embolization may occur in 8% of patients awaiting operation.21 The usual approach is through a median sternotomy and ascending aortic and bicaval cannulation. Minimally invasive approaches are also being employed and include right parasternal and partial median sternotomy incisions.22 Regardless of the approach, it is important to minimize manipulation of the heart prior to cardiopulmonary bypass so as to avoid any embolic risk.
Left atrial myxomas can be approached either through a biatrial incision or through the anterior wall of the left atrium anterior to the right pulmonary veins. Full excision of the interatrial septal attachment is necessary and patch closure of the septum is then performed. Right atrial myxomas require attention to be placed with regards to the venous cannulation. If the tumor precludes safe transatrial cannulation, the jugular or femoral vein can be employed for drainage. Ventricular myxomas are usually approached through the atrioventricular valve.23 It is unusual to excise the tumor through an incision into the ventricle.
Removal of atrial myxomas carries an operative mortality rate of 5% or less with mortality related to increased age and comorbid conditions.3 Recurrence with nonfamilial sporadic myxoma is 1-4% or less, and is 22% in patients with familial complex myxomas.1,2
In reviewing the published literature with respect to our patient, there is one report in the Romanian literature that refers to a patient who was treated for one year for bronchitis and asthma before being diagnosed and treated for an atrial myxoma.24 The only other reference is cited in the
This case report focuses on a young patient who was initially diagnosed with asthma and treated as such for six months. It illustrates the importance of taking a detailed history, and performing a thorough physical exam to aid in establishing a diagnosis. We would also like to emphasize that in young patients who present with new onset asthma, one should include atrial myxoma in the differential diagnosis. A heart murmur on exam and an echocardiogram should establish the diagnosis and allow operative intervention in a timely fashion. There are only two citations in the literature regarding patients who were diagnosed with asthma and were found to have an atrial myxoma. It certainly is an uncommon presentation for myxoma but it is imperative that it remains in the differential diagnosis so treatment is not unnecessarily delayed.
Samer Kanaan, MD 1520 San Pablo Street, Suite 4300 Los Angeles, CA 90033 Phone: 323 442 5849 Fax: 323 442 5956 firstname.lastname@example.org