Ann Thorac Surg 2008;86:1004-1006. doi:10.1016/j.athoracsur.2008.02.048
© 2008 The Society of Thoracic Surgeons
Case Reports
Endomyocardial Fibrosis in an Adult Mimicking Left Ventricular Mass
Karthik R. Vaidyanathan, MS*,
Rajesh Venkatraman, MCh,
Madhu N. Sankar, DNB, PhD,
Kotturathu M. Cherian, FRACS
Department of Cardiac Surgery, Frontier Lifeline and Dr K. M. Cherian Heart Foundation, International Center for Cardiothoracic and Vascular Diseases, Chennai, India
Accepted for publication February 18, 2008.
* Address correspondence to Dr Vaidyanathan, Department of Cardiac Surgery, International Centre for Cardiothoracic and Vascular Diseases, R-30-C Ambattur Industrial Estate Rd, Mogappair, Chennai, 600 101, India (Email: rkvdoc{at}rediffmail.com).
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Abstract
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Endomyocardial fibrosis is a rare condition that occurs primarily in tropical countries. It can often mimick a variety of other common cardiac conditions such as apical hypertrophic cardiomyopathy and Ebstein anomaly. We report a case of a left ventricular mass that at histologic examination was found to be endomyocardial fibrosis.
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Introduction
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Endomyocardial fibrosis (EMF) is a rare condition that is more prevalent in tropical countries. It is characterized by diffuse fibrous thickening of the endocardium or subendocardial layer. Its rarity sometimes makes preoperative diagnosis difficult. Very few cases of isolated left ventricular (LV) endomyocardial fibrosis have been reported in the literature. We report a case of isolated localized LV EMF that was preoperatively diagnosed as LV tumor.
A 25-year-old man with a history of allergic bronchopulmonary aspergillosis since childhood had New York Heart Association class II dyspnea of recent onset. Findings at clinical examination, chest radiography, and electrocardiography were unremarkable. Two-dimensional echocardiography revealed an apical LV tumor involving the anterior papillary muscle. The valvar and subvalvar myocardia were normal. There was no mitral valve regurgitation on color Doppler interrogation (GE Vivid 7 Pro, General Electric Healthcare, Piscataway, New Jersey). Subsequently magnetic resonance imaging (MRI) was performed, which revealed a sessile LV tumor obliterating the apex (Fig 1). The mitral valve was normal, and there was no intracavitary or LV outflow tract obstruction. Left ventricular function was normal. Trans–left atrial excision of the tumor was performed through a median sternotomy with cardiopulmonary bypass. Intraoperatively there was a dimpling at the apex with akinesia of the apical region. A 3-cm ulcerative mass was seen at the apex. Trans-atrial excision was attempted. For better exposure the anterior mitral leaflet was detached from its annulus. A hard mass with necrotic areas inside was excised. There was involvement of the base of the anterolateral papillary muscle, which was sacrificed. Hence the mitral valve was replaced with a mechanical valve. Postoperative recovery was uneventful. Histopathologic analysis revealed features suggestive of EMF. At 3-month follow-up the patient was doing well.
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Fig 1. (A) Delayed enhancement of a ventricular tumor (arrows) suggests fibrosis. (B) HASTE (half-Fourier acquisition single-shot turbo spin-echo) images show a tumorlike lesion obliterating the ventricular apex.
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Comment
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Endomyocardial fibrosis is a progressive restrictive cardiomyopathic condition frequently observed in tropical and subtropical regions. It affects either or both ventricles and is characterized by infiltration and fibrous atrophy of the endocardium and subendocardial myocardium of the inflow tract, the apical wall, and subvalvular tissues such as the papillary muscles, resulting in ventricular diastolic dysfunction and valve regurgitation [1]. The initial pathological event in EMF is hypothesized to be some form of subendocardial inflammation that progresses to involve the endocardium. This in turn leads to formation of mural thrombi that organize to form a fibrous peel [2]. Immunologic abnormalities such as abnormal eosinophils have been proposed as the inciting factor for the initial inflammation [3]. Increased serotonin found in tropical bananas can also lead to endocardial fibrosis analogous to that seen in carcinoid tumor of the heart [4]. Serotonin acts additively with eotaxin (a critical factor for the selective recruitment of eosinophils after allergen challenge) to act as an eosinophil chemoattractant, thereby initiating subendocardial inflammation [5]. Further, increased cerium levels have been noted in hearts with EMF and in tubers found in areas where EMF is endemic [6, 7]. Thus numerous etiologic factors have been postulated, although none has been confirmed.
The clinical features of EMF are nonspecific. Most patients with EMF present heart failure symptoms, often preceded by fever, physical weakness, and fatigue [1]. Careful evaluation is required because there are no characteristic symptoms of EMF and in some patients the condition remains completely asymptomatic. The diagnosis of EMF is usually made at 2-dimensional echocardiography or ventricular angiography and is often confirmed at endocardial biopsy. Endomocardial fibrosis, because of its rarity, can sometimes be misdiagnosed as rheumatic heart disease, constrictive pericarditis, apical hypertrophic cardiomyopathy, dilated or restrictive cardiomyopathy, or Ebstein anomaly of the tricuspid valve [8]. Obliteration of the apex is the hallmark of EMF and occurs in most cases with LV involvement and in almost all cases of right ventricular EMF, and serves to differentiate it from other conditions [8].
The gross morphologic features of EMF have been extensively described by Davies and Ball [2]. Most commonly, pearly white plaques with firm rolled edges and a rugose surface are seen over the endocardium. Less frequently but not uncommonly, an organized mural thrombus is seen over the fibrous plaque, giving rise to a tumorlike appearance. This can be mistaken for cardiac tumor on standard echocardiographic images. However, this tumorlike lesion can be readily recognized as EMF by its homogeneous enhancement on contrast-enhanced magnetic resonance images and by high signal intensity on T2-weighted images [9]. Delayed hyperenhancement of subendocardial myocardium is another differentiating feature of EMF [10]. This was noted retrospectively in our patient (Fig 1A). Contrast blush can also be demonstrated because of ingrowth of neocapillaries in the organized thrombus [9]. Thus the use of advanced imaging methods as a supplement to the clinical and echocardiographic or angiographic findings can lead to a precise diagnosis of EMF without resorting to invasive and relatively insensitive endomyocardial biopsy studies.
The only treatment option for EMF in patients with advanced heart failure is complete endomyocardial resection with or without replacement of the atrioventricular valve. Trans-atrial resection can be performed in almost all cases. Ventriculotomy, especially for apical resection, is rarely required and may lead to arrythmias, ventricular dysfunction, and possibly late aneurysm formation [11]. An alternative procedure is combined trans-atrial trans-aortic endocardectomy [11]. The need for atrioventricular valve replacement depends on the involvement of the valve apparatus, and, in general, most patients will require valve replacement. The long-term results of surgery to treat EMF have been reported by Moraes and colleagues [12]. Actuarial survival, with or without valve replacement, is 55% at 17 years. Recurrence at the same site or elsewhere in the heart has been reported as 6% and 9%, respectively. Repeat operation either to replace a valve prosthesis or a previously preserved valve is required in as many as 7% of patients.
Endomyocardial fibrosis should be considered in the differential diagnosis of tumorlike lesions involving the ventricular apex. Although echocardiography can aid in the diagnosis of such lesions, contrast-enhanced magnetic resonance imaging can provide valuable information about the pathologic features, leading to the reasonable probability of a diagnosis of EMF.
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References
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- Niino T, Shiono M, Yamamoto T, et al. A case of left ventricular endomyocardial fibrosis Ann Thorac Cardiovasc Surg 2002;8:173-176.[Medline]
- Davies JNP, Ball JD. Pathology of endomyocardial fibrosis in Uganda Br Heart J 1955;17:337-358.[Free Full Text]
- Sezi CL. Endomyocardial fibrosis and eosinophilia Lancet 1993;342:1233-1234.[Medline]
- Shaper AG. Plantain diets, serotonin, and endomyocardial fibrosis Am Heart J 1967;73:432-434.[Medline]
- Boehme SA, Lio FM, Sikora L, et al. Serotonin is a chemotactic factor for eosinophils and functions additively with eotaxin J Immunol 2004;173:3599-3603.[Abstract/Free Full Text]
- Eapen JT, Kartha CC, Valiathan MS. Cerium levels are elevated in the serum of patients with endomyocardial fibrosis Biol Trace Elem Res 1997;59:41-44.[Medline]
- Eapen JT. Elevated levels of cerium in tubers from regions endemic for endomyocardial fibrosis Bull Environ Contam Toxicol 1998;60:168-170.[Medline]
- Hassan WM, Fawzy ME, Al Helaly S, Hegazy H, Malik S. Pitfalls in diagnosis and clinical, echocardiographic, and hemodynamic findings in endomyocardial fibrosis: a 25-year experience Chest 2005;128:3985-3992.[Medline]
- Goo H, Han N, Lim T-H. Endomyocardial fibrosis mimicking right ventricular tumor AJR 2001;177:205-206.[Free Full Text]
- Cury RC, Abbara S, Sandoval LJ, Houser S, Brady TJ, Palacios IF. Visualization of endomyocardial fibrosis by delayed-enhancement magnetic resonance imaging Circulation 2005;111:e115-e117.[Free Full Text]
- Joshi R, Abraham S, Kumar S. New approach for complete endocardiectomy in left ventricular endomyocardial fibrosis J Thorac Cardiovasc Surg 2003;125:40-42.[Free Full Text]
- Moraes F, Lapa C, Hazin S, Tenorio E, Gomes C, Moraes CR. Surgery for endomyocardial fibrosis revisited Eur J Cardiothorac Surg 1999;15:309-313.[Abstract/Free Full Text]
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Abstract
Introduction
