What is Atrial Myxoma?
Pathophysiology
Myxomas account for 40-50% of number one cardiac tumors. Approximately 90% are solitary and pedunculated, and 75-85% arise withinside the left atrial cavity. Up to 25% of instances are determined withinside the proper atrium. Most instances are sporadic. Approximately 10% are familial and are transmitted in an autosomal dominant mode. Multiple tumors arise in about 50% of familial instances and are greater regularly placed withinside the ventricle (13% vs 2% in sporadic instances).
Although atrial myxomas are usually benign, nearby recurrence because of insufficient resection or malignant alternate has been suggested. Occasionally, atrial myxomas recur at a far-off web website online due to intravascular tumor embolization. The danger of recurrence is better withinside the familial myxoma syndrome. [1]
Symptoms from a cardiac myxoma are produced through mechanical interference with cardiac characteristic or embolization and greater mentioned while the myxomas are left-sided, racemose, and over five cm in diameter. [2] Because the tumors are intravascular and friable, myxomas account for maximum instances of tumor embolism, which happens in approximately 30-40% of sufferers. The web website online of embolism is depending on the tumor location (left or proper atrium) and the presence of an intracardiac shunt. A case of a couple of peripheral pulmonary artery aneurysms has been suggested in affiliation with a proper atrial myxoma. [3] Most of the aneurysms had thrombi and have become smaller following the disappearance of thrombi after resection of the proper atrial myxoma. However, a few aneurysms have become barely larger. [3]
Ha and pals suggested a greater common prevalence of systemic embolism in polypoid tumors in comparison to round (58% vs 0%). [4] Also, polypoid tumors greater regularly prolapse into the ventricle. The prolapse of a tumor via the mitral or tricuspid valve might also additionally bring about the destruction of the annulus or valve leaflets. In one study, 19% of the sufferers had atrial traumatic inflammation related to big atrial myxomas. Tumors range extensively in size, starting from 1 to fifteen cm in diameter, with the charge of increase now no longer precisely known. In one case report, proper atrial myxomas had an increased charge of 1.36 × 0.03 cm/mo. Myxomas are vascular tumors and can be neovascularized through a department of a coronary artery. [5] A case of hemorrhage in a left atrial myxoma has been suggested. [6]
Myxomas had been validated to supply several increase elements and cytokines, which include vascular endothelial increase factor, ensuing in angiogenesis and tumor increase and an extended-expression of the inflammatory cytokine, interleukin-6
Etiology
Most instances of atrial myxoma are sporadic, and the precise etiology is unknown.
Familial atrial myxomas have an autosomal dominant transmission.
Carney syndrome is genetically heterogeneous and is a result of an illness in multiple genes. It is expected to account for 7% of all atrial myxomas with no predilection for age or intercourse. Abnormalities withinside the quick arm of chromosome 2 (Carney) and chromosome 12 (Ki-ras oncogene) were described. In one case report, a frame-shift mutation turned into determined in exon 2 withinside the causative gene of Carney complex, protein kinase A regulatory subunit 1 alpha (PRKAR1A). [10]
At present, there does now no longer appear like an affiliation among cardiac myxomas and herpes simplex sorts 1 and 2.
Epidemiology
United States statistics
Based upon the statistics of twenty-two huge post-mortem series, the superiority of number one cardiac tumors is about 0.02% (2 hundred tumors according to million autopsies). About seventy five% of number one tumors are benign, and 50% of benign tumors are myxomas, ensuing in seventy-five instances of myxoma according to million autopsies.
International statistics
Surgical prevalence withinside the Republic of Ireland from 1977-1991 turned into 0.50 atrial myxomas according to million populace according to year.
Sex- and age-associated demographics
Approximately seventy-five% of sporadic myxomas arise in females. In a chain of sixty-six cardiac myxomas, the girl-to-male ratio turned into 2.7:1. [12] However, girl intercourse predominance is much less reported in familial atrial myxomas. In a retrospective evaluation of 367 sufferers, there have been 28 instances of proper atrial myxoma, of which sixteen took place in adult males and 12 in females. [13]
Myxomas were suggested in sufferers elderly 3-eighty three years. The suggested age for sporadic instances is fifty-six years; while it’s miles 25 years for familial instances. In a retrospective overview of 171 sufferers from India, the suggested age of presentation turned 37.1 years. Most of those sufferers have been symptomatic; dyspnea turned into the maximum, not unusual place symptom.
Prognosis
Morbidity/mortality
Atrial myxomas are histologically benign however may be risky due to the capability for systemic and cerebral embolism. [15] Factors related to an improved threat of embolism in people with left atrial myxoma consist of the presence of atrial fibrillation, an abnormal tumor surface, a bigger tumor size, and an improved left atrial diameter. [15]
Sudden loss of life can also additionally arise in 15% of sufferers with atrial myxoma, commonly as a result of coronary or systemic embolization or with the aid of using obstruction of blood go with the drift on the mitral or tricuspid valve.
Morbidity is associated with signs and symptoms produced with the aid of using tumor embolism, coronary heart failure, mechanical valvular obstruction, and numerous constitutional signs and symptoms.
In a single-middle observation of sixty-two sufferers with cardiac myxoma, actuarial survival changed to 96.8 ± 1.8% at 10 years. Most sufferers had been asymptomatic following the surgery, without recurrence. Recurrence befell simplest in familial instances of left atrial myxoma. Freedom from reoperation changed into 98.4 ± 1.3% at five years and 96.8 ± 1.8% at 10 years. [16]
Complications
Complications of atrial myxoma consist of the following:
Congestive coronary heart failure
Sudden loss of life
Infection
Rupture [17]
History
Symptoms of atrial myxomas variety from nonspecific and constitutional to surprising cardiac death. [19] In approximately 20% of instances, myxomas can be asymptomatic and located as an incidental finding. Signs and signs and symptoms of mitral stenosis, endocarditis, mitral regurgitation, and collagen vascular sickness can simulate the ones of atrial myxoma. An excessive index of suspicion aids in prognosis.
Symptoms of left-sided coronary heart failure encompass the following:
Dyspnea on exertion (75%) that could develop to orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema is discovered. [20, 21]
Symptoms are due to obstruction on the mitral valve orifice. Valve harm might also additionally bring about mitral regurgitation.
Symptoms of proper-sided coronary heart failure encompass the following:
Patients enjoy fatigue and peripheral edema.
Abdominal distention because of ascites is rare; however, it’s miles extra not unusual place in slowly developing proper-sided tumors. [22]
These signs and symptoms also are discovered withinside the later level of innovative coronary heart failure related to left atrial myxomas.
Severe dizziness/syncope is skilled via way of means of about 20% of sufferers. The maximum common motive in sufferers with left atrial myxomas is obstruction of the mitral valve. Symptoms might also additionally extrude because the affected person modifications positions.
Symptoms associated with embolization encompass the following:
Systemic or pulmonary embolization might also additionally arise from left- or proper-sided tumors.
Embolization to the principal worried machine might also additionally bring about the temporary ischemic attack, stroke, or seizure. [23] In an evaluation of 113 instances of atrial myxoma with the neurologic presentation, 83% of sufferers provided with ischemic stroke, most usually in a couple of sites (43%). Twelve percentage of sufferers were provided with seizures. In a retrospective evaluation of seventy-four sufferers with atrial myxoma, 12% had neurologic manifestations. [24] Cerebral infarction become found in 89% of the instances and maximum myxomas (89%) confirmed a cell thing on transesophageal echocardiography. Other headaches encompass myxoma-brought about cerebral aneurysm and myxomatous metastasis which can mimic vasculitis or endocarditis.
Involvement of the retinal arteries might also additionally bring about imaginative and prescient loss.
Systemic embolization that reasons occlusion of an artery, inclusive of coronary, aortic, renal, visceral, or peripheral, might also additionally bring about infarction or ischemia of the corresponding organ.
On the proper side, embolization outcomes in pulmonary embolism and infarction.
Multiple, recurrent small emboli might also additionally bring about pulmonary high blood pressure and cor pulmonale.
The presence of an intracardiac shunt (atrial septal disorder or patent foramen ovale) might also additionally bring about a paradoxical embolism.
Constitutional signs and symptoms that encompass fever, weight loss, arthralgias, and the Raynaud phenomenon are discovered in 50% of sufferers. These signs and symptoms can be associated with the overproduction of interleukin-6.
Hemoptysis because of pulmonary edema or infarction is discovered in as much as 15% of sufferers.
Chest ache is infrequent. If it occurs, it can be because of coronary embolization.
A case document of 5-12 months records of visible loss, vertigo, ataxia, tinnitus, and bone lesions that resolved after prognosis and resection of the atrial myxoma has raised the opportunity of it inflicting a paraneoplastic syndrome.
Atrial myxoma can grow to be inflamed whilst vegetations can be visibly connected to its surface.
Cardiac myxoma in being pregnant is rare, and prognosis and control can be hard as fatigue and dyspnea aren’t unusual in everyday being pregnant. Transthoracic echocardiography can useful resource withinside the prognosis. In maximum instances, the prognosis is made withinside the 2d trimester and surgical resection is finished withinside the 0.33 trimester.
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