Intracardiac mass revealing a rare form of cardiomyopathy

Abstract

We present the case of a woman with a 2-month history of exertional dyspnoea and fatigue in which echocardiography revealed a cavity-obliterating right ventricular mass. Further imaging evaluation using cardiac magnetic resonance showed a thrombotic mass as well as diffuse myocardial oedema and endomyocardial fibrosis (EMF) that involved both ventricles. In the absence of any other cause (including peripheral eosinophilia), the diagnosis of idiopathic EMF was established. This case highlights this uncommon disease in non-tropical areas.

Background

Endomyocardial fibrosis (EMF) is the most common restrictive cardiomyopathy worldwide, but it is typically seen in tropical regions. Patients with EMF may develop fibrosis of the apical endocardium of one or both ventricles, usually presenting with apical thrombotic obliteration with marked areas of fibrotic tissue and calcification.^{1 2} While researchers have proposed various possible triggers for EMF, aetiology and pathogenesis remain largely unknown. It has no specific treatment and carries a poor prognosis since most patients present with advanced and irreducible heart failure.

Case presentation

A woman in her 50s, with no significant medical history, presented with a 2-month history of exertional dyspnoea and fatigue. She described progressively worsening fatigue in the month leading up to admission. She smoked and occasionally drank alcohol. There had been no international travel for more than 5 years, and her family history was insignificant. At admission, the patient’s temperature, blood pressure, heart rate and peripheral oxygen saturation were normal. On physical examination, the patient had mild pitting oedema, abdominal distention with hepatosplenomegaly and a systolic murmur over the tricuspid area.

Investigations

Electrocardiography revealed sinus rhythm with narrow QRS complex and a poor R-wave progression from V1 to V3.

Transthoracic echocardiography documented right ventricular apical obliteration by an intracardiac mass (video 1) and left ventricular pseudohypertrophy in the apical region (video 2). There was shrinkage of the right ventricle cavity creating an apical notch. In addition, there were severe biatrial enlargement, severe tricuspid regurgitation (figure 1), moderate mitral regurgitation, restrictive flow pattern across the mitral valve, dilated inferior vena cava and mild pericardial effusion.

Video 1.

bcr-2022-249037supp001.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2022-249037.video01

Video 2.

bcr-2022-249037supp002.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2022-249037.video02

Figure 1.

Transthoracic echocardiography, apical four-chamber view: biatrial enlargement with severe tricuspid regurgitation.

A cardiac magnetic resonance evaluation was performed, which showed the obliteration of both ventricular apices with preserved biventricular systolic functions (left ventricular ejection fraction=75%, right ventricular ejection fraction=55%) (video 3) and biatrial enlargement (left atrial volume index=70 mL/m², right atrial volume index=62 mL/m²). Early gadolinium-enhanced and late gadolinium-enhanced imaging revealed extensive EMF with two thrombotic masses, one in each apex (figure 2). Furthermore, T2-weighted sequences and T1 and T2 mapping detected diffuse myocardial oedema and fibrosis that involved both apices transmurally (figure 3). Thus, the MRI findings are suggestive of the diagnosis of EMF.

Video 3.

bcr-2022-249037supp003.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2022-249037.video03

Figure 2.

Cardiac MRI: (A) early gadolinium-enhanced image; (B) late gadolinium-enhanced image. Extensive endomyocardial fibrosis (yellow arrows) with thrombotic masses (red arrows) in both ventricles.

Figure 3.

Cardiac MRI: T1 mapping image showing diffuse myocardial fibrosis (white arrows) involving the left ventricle apex (T1 ~1400 ms).

Blood test results on presentation revealed the following: haemoglobin 115 g/L (117–160 g/L), white cell count 4.5×10⁹/L (4–10×10⁹/L), eosinophils 6% (0%–7%), creatinine 1.18 mg/dL (0.57–1.11 mg/dL), erythrocyte sedimentation rate 21 mm/hour (2–12 mm/hour), high-sensitive cardiac troponin T 28.5 pg/mL (0–14 pg/mL) and lactate dehydrogenase 524 U/L (125–220 U/L). Moreover, repeated eosinophil count was always normal.

Differential diagnosis

To our surprise, her eosinophil count was not high enough to be characterised as having the hypereosinophilic syndrome and remained so on subsequent evaluations. Parasitic infections, autoimmune disorders and haematological malignancies were excluded by extensive laboratory work-up. A CT was performed to exclude thrombosis in other areas and pulmonary embolism. It also excluded the presence of eosinophil accumulation in the lungs, liver and spleen.

Based on clinical and imaging results, the diagnosis of idiopathic EMF has been established.

Treatment

Medical management consisted of symptomatic treatment of heart failure (diuretic, ACE inhibitor and beta blocker) and anticoagulation was initiated.

Outcome and follow-up

In the following months, the patient’s clinical condition was gradually deteriorating with worsening of pre-existing symptoms: decreasing walking distances and increasing signs of congestion. Adjustment of the treatment was required by increasing the dose of diuretics. Because of the continuously elevated international normalised ratio values, despite low doses of vitamin K antagonist, acenocumarol was replaced with a direct oral anticoagulant (rivaroxaban).

At this point, surgical treatment consisting of resection of fibrotic tissue was considered, but studies suggest a poorer prognosis for those who also need valve repair or replacement (which is the case of our patient because of the severe tricuspid regurgitation). The patient was listed for heart transplantation.

Discussion

This patient with the rare diagnosis of EMF outside tropical regions presented to our department with shortness of breath and oedema in both legs for a period of 2 months. The pathological hallmarks of the disease were identified: obliteration and endocardial surface thrombi in both ventricles. Our work-up did not reveal any other diseases typically associated with eosinophilia and/or EMF including parasitic infection, malignancy or autoimmune disorders.

The irreversible nature of EMF is well known, and the clinical course depends on the severity of the ventricular fibrosis and the degree of mitral and/or tricuspid incompetence.³ An unfavourable prognosis of this patient is expected, influenced by the biventricular involvement of significant valvular disease. Therefore, the heart team considers the heart transplant as the best treatment option for this patient. EMF is a neglected, underdiagnosed disease. Regional occurrence, unclear aetiology and lack of standard diagnostic criteria have contributed to the misperception of this condition. It causes restrictive cardiomyopathy and, eventually, advanced heart failure. The aetiology of EMF is poorly understood, and treatment options are limited.⁴ Despite a high prevalence in tropical regions, it occasionally occurs in patients who have never visited these areas. Even in non-tropical regions, the diagnosis of EMF should always be considered in restrictive cardiomyopathy. Cardiac MRI has a definitive role in confirming and characterising EMF and is better than echocardiography for delineating the extent of cavity obliteration and the presence of intracardiac thrombi.⁵

Learning points.

• Endomyocardial fibrosis (EMF) is a rare condition with a high rate of mortality and morbidity.

• Even though hypereosinophilia is the most common aetiology for EMF, its absence does not exclude the diagnosis.

• The natural history of EMF includes progressive heart failure.

• Treatment options are limited; surgical intervention appears to be the only solution for most advanced cases.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).