Nigerian Journal of Cardiology

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 15  |  Issue : 2  |  Page : 89--93

Clinical utility of transthoracic echocardiography in assessing frequency and pattern of atrial masses among patients with cardiac diseases


Tolulope Taiwo Shogade, Ime Okon Essien, Idongesit Odudu Umoh, Clement Tom Utin, Joseph John Andy 
 Department of Internal Medicine, Division of Cardiology, University of Uyo Teaching Hospital, Akwa-Ibom, Nigeria

Correspondence Address:
Dr. Tolulope Taiwo Shogade
Department of Internal Medicine, University of Uyo Teaching Hospital, PMB 1136, Uyo, Akwa-Ibom
Nigeria

Abstract

Background: Echocardiography plays a fundamental role in the evaluation of patients with atrial masses. The ability to distinguish tissue characteristics such as location, attachment, shape, size, and mobility noninvasively, quickly, cheaply, and without the use of ionizing radiation makes echocardiography the ideal diagnostic modality. With careful attention to mass location and morphology and appropriate application of clinical information, echocardiography can usually distinguish between the three principal atrial masses as follows: tumor, thrombus, and vegetation. Although transesophageal echocardiography has better sensitivity and specificity for detecting atrial masses, transthoracic echocardiography (TTE) can also detect atrial masses with specificity and sensitivity of about 58% and 98%, respectively. Objectives: The study is aimed at assessing the frequency and patterns of atrial masses in an urban teaching hospital using TTE. Materials and Methods: A retrospective review of our echocardiogram reports from July 2009 to June 2014 was done to identify the frequency of atrial masses, gender distribution, sizes, clinical presentations, and locations. Results: A total of 1027 echo examinations were done over this period, comprising 503 males (48.98%) and 524 females (51.02%). Nonvegetative atrial masses were found in six of these patients representing 0.58% of the study population. Myxoma was the most common mass noted, 3 out of 4 were found in female, and all were found in the left atrium. The two atrial thrombi were detected in the right atrium and both were found in males. Conclusion: Atrial masses are not rare and TTE is still valuable in the diagnosis and initial characterization of atrial masses.



How to cite this article:
Shogade TT, Essien IO, Umoh IO, Utin CT, Andy JJ. Clinical utility of transthoracic echocardiography in assessing frequency and pattern of atrial masses among patients with cardiac diseases.Nig J Cardiol 2018;15:89-93


How to cite this URL:
Shogade TT, Essien IO, Umoh IO, Utin CT, Andy JJ. Clinical utility of transthoracic echocardiography in assessing frequency and pattern of atrial masses among patients with cardiac diseases. Nig J Cardiol [serial online] 2018 [cited 2019 Dec 7 ];15:89-93
Available from: http://www.nigjcardiol.org/text.asp?2018/15/2/89/262003


Full Text



 Introduction



Echocardiography plays a fundamental role in the evaluation of patients with atrial masses, the ability to distinguish tissue's location, attachment, shape, size, and mobility noninvasively, quickly, cheaply, and without the use of ionizing radiation while defining the presence and extent of any consequent hemodynamic derangement makes echocardiography the ideal diagnostic modality.[1]

With appropriate application of clinical information and careful attention to mass location and morphology, echocardiography can usually distinguish between the three principal atrial masses as follows: tumor, thrombus, and vegetation.[2] Transthoracic echocardiography (TTE), an excellent initial noninvasive diagnostic technique to evaluate and diagnose cardiac masses, however, transesophageal echocardiography (TEE) provides superior image resolution and better visualization of cardiac masses in atrial appendages and superior vena cava, especially in patients with suboptimal transthoracic echocardiographic studies.[3],[4]

TTE can also detect atrial masses with specificity and sensitivity of about 58% and 93%, respectively, which is important, especially where TEE is not readily available.[5]

Magnetic resonance imaging (MRI) has proved to be the gold standard for the assessment of these masses, but the widespread availability, portability, absence radiation exposure, and additional functional information provided by echocardiography makes it the initial investigation of choice for the assessment of atrial masses.[6]

Atrial masses are most commonly due to thrombi or valvular vegetations, less commonly a variety of atrial tumors may be detected by echocardiography. Tumors in the atrium most commonly occur in the setting of metastatic diseases, usually from malignancies of the thyroid, breast, kidney, lung, or from malignant melanoma. About 20% of patients with malignancies reportedly have cardiac involvement.[7] In contrast, primary cardiac tumors occur much less frequently and about 75% are usually benign.[8]

Atrial myxomas constitute nearly one half of reported cases of benign primary cardiac tumors in adults.[9] Other benign cardiac tumors are lipomas, papillary fibroelastomas, and rhabdomyomas.[1] There are several normal structures and variants that may mimic a cardiac mass, such as the eustachian valve, Chiari network, crista terminalis, moderator band, pectinate muscles, trabeculations, and lipomatous hypertrophy of the interatrial septum as well as non cardiac structure such as hiatus hernia.[10] Therefore, the echocardiographic evaluation of intra cardiac masses is dependent on the ability to distinguish the normal from abnormal findings.

There is a dearth of data on the types and locations of atrial masses detected by echocardiography in this environment thus necessitating the need for this study.

 Materials and Methods



The University of Uyo Teaching Hospital (UUTH), where this study was conducted, is the lone tertiary health institution located in the state, which has a population of 3.9 million people (2006 census). During the period under review, it provided echocardiographic services to people in the state and neighboring states.

The consecutive 1027 echocardiogram reports done over a period of 5 years at UUTH and between July 2009 and June 2014 were reviewed. All patients who had atrial masses on TTE were included in the study.

Echocardiography was done with either a Hewlett Packard SONOS 4500 and 5500 or Toshiba echocardiographic machine equipped with 3.5 MHz transducer, a video recorder, and printout processor. The machines have capacities to perform M-mode, two-dimensional (2D), and Doppler examinations. The echocardiographic examinations were performed and interpreted by three cardiologists.

All measurements were taken from standard echocardiographic views according to the recommendation of the American Society of Echocardiography.[11],[12] Data obtained from the echocardiography register included age, gender, clinical diagnosis, and chambers' dimensions, location and size of mass in the heart. Data obtained were presented in tabular forms.

 Results



There were 1027 echocardiographic examinations in adults over this period, comprising 503 males (48.98%) and 524 females (51.02%). Atrial masses were found in six patients representing 0.58% of the study population. [Table 1] shows the age- and sex-distribution pattern of patients with atrial masses. The age range of patients with atrial masses was from 19 to 64 years with a mean of 38 ± 18 years. Male was younger than the female.{Table 1}

[Table 2] shows the echocardiographic patterns of patients with atrial masses.{Table 2}

Three females and three males had atrial masses. The frequency of atrial chamber involvements was as follows – left atrium (LA) (4) and right atrium (RA) (2). The atrial masses were four myxomas and two thrombi.

Left atrial masses

The four masses in the LA which was presumed to be myxomas considering there anatomical locations and echocardiographic features. The masses were attached to the mid portion of the interatrial septum; female-to-male distribution was 3: 1. The age range was 19– 64 years. Two of the masses were confirmed by histological diagnosis after resection.

Right atrial masses

There were two masses in the RA, all were found in males and all were thrombi. The thrombi were found in patients with right-sided endomyocardial fibrosis and markedly dilated RA.

[Figure 1]a shows the 2D echocardiographic apical four chamber view of 54 year old woman with left atrial myxoma, pre and post excision of the myxoma. [Figure 1]b shows 2D echocardiographic parasternal long axis view of a 42 year old woman with left atial myxoma with a ball valve effect. [Figure 1]c shows 2D echocardiographic apical four chamber view of right atrial thrombus in a 19 year old male with right sided endomyocardial fibrosis.{Figure 1}

 Discussion



The frequency of atrial masses in our study was 0.58% and specifically for atrial tumors was 0.39%. Similar studies in the past had recorded frequencies ranging from 0.001% to 0.71% at autopsies.[13],[14] Most of these studies were, however, on cardiac tumors and not necessarily atrial masses or tumors only. Echocardiography provides an excellent diagnostic technique for detection of atrial masses [Table 1]. All the atrial tumors in our study were presumed to be a myxoma; this finding could be because TEE modality was not used in the evaluation, thus the increased likelihood of missing smaller tumors and tumors located in the posterior portions of the heart.

In contrast, Talle et al.[15] reported a higher prevalence of 8.7% for various kinds of cardiac masses among patients that had TTE over a 3-year period at a Tertiary Hospital in North Eastern Nigeria. In their study, intracardiac thrombus was the most common form of cardiac masses; this is in keeping with the fact that thrombus commonly complicates pathologies of left ventricle such as myocardial infarction, dilated cardiomyopathy, and chronic left ventricular aneurysm.[16] Our report is based on TTE, the lack of finding of the left atrial thrombus might not reflect its true occurrence since TEE is required to establish its presence or otherwise with certainty.[17]

In a retrospective study by DeVille et al. at Texas Heart Institute, where both TTE and TEE were used to evaluate 21 patients with intracardiac masses, 18 patients had masses in the atrial chambers, 11 of which are tumors, malignant tumors accounted for 45%, myxoma accounted for 66% of the benign tumors which were lower than what we reported.[18]

In our study, all the four myxoma-like masses were found in the LA attached to the inter atrial septum in the region of the fossa ovalis, which is suggested to be the most common site of attachment of atrial myxoma and is one of the criteria for the diagnosis of myxoma. This is similar to the findings of Yu et al.[13] and Ejim et al.[14] in UNTH, Nigeria. Their locations thus helped to increase the probability that they were myxoma. Two out of which were confirmed by histology after resection.[1]

Noteworthy that myxoma can also originate anywhere within the heart including the appendage, the cardiac valves, pulmonary artery and vein, and vena cavae.[19] Our study also supports the previous study that showed that myxoma typically affects patients 30–60 years old with higher prevalence in female, this is because 75% of patients with myxoma in our study were female, with the age range of 42–64 years.[9] The sensitivity of 2D echocardiography for myxomas is 100%. TTE usually provides all the information for surgical resection.[20],[21]

One-third of the atrial masses were thrombi, all of which were found in markedly dilated right atrium in patients with right ventricular endomyocardial fibrosis. This figure is lower than 42% reported by DeVille et al., in their study, thrombi were distributed between the left and right atria in ratio 2:1.[18] In contrast, all the atrial thrombus reported by Talle et al.[15] were in the LA, while all the myxoma were in the RA. Similarly, a higher proportion of LA thrombus was reported in Enugu, although the underlying predisposition was not mentioned.[14]

Previous studies have also suggested that, though atrial thrombi are infrequently seen on transthoracic study, they have been observed in patients with the central venous line, pulmonary emboli, or endomyocardial fibrosis.[7],[22]

Atrial fibrillation was present in one out of the two cases of atrial thrombi. This is in agreement with the suggestion that thrombi are commonly associated with atrial fibrillation, atrial flutter, mitral stenosis, or prosthetic mitral valve.[3] Thrombus often occurs in dilated chambers and area of blood stasis, the presence of spontaneous echo contrast provides important supportive evidence to the thrombotic nature of an intracardiac mass.[4]

Thrombi in the absence of underlying cardiac disease may be difficult to distinguish from myxoma on transthoracic study. Several characteristic features may assist in the distinction between thrombi and myxomas. For example, myxomas are rarely calcified and usually present as a solitary mass. However, the appearance of myxomas and thrombi is highly variable, and definitive diagnosis may require pathologic examination.[4]

None of the thrombi was found in the LA this is likely because >90% of the left atrial thrombi are located in the atrial appendage which is difficult to view by TTE.[20] It is noteworthy that sometimes thrombi in the right chambers can also be underdiagnosed because of the position and poor visibility during echocardiography.

Both MRI and multidetector computed tomography have been shown to further improved diagnostic capabilities for cardiac tumor by delineating tumors, assessing their impact on cardiac function, and planning for surgical intervention.[23]

 Conclusion



Although atrial masses are uncommon in this environment, echocardiography is the procedure of choice for the evaluation of atrial masses. TTE when meticulously applied with cautious data interpretation and appropriate application of clinical information is still valuable in the diagnosis and initial characterization of atrial masses despite its limitations.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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