Largest giant left atrium in rheumatic heart disease

Abstract

In the current era of echocardiography, early diagnosis and treatment of rheumatic heart disease make giant left atrium a rare condition, with a reported incidence of 0.3%, and following mainly with rheumatic mitral valve disease. We report a 50-year-old female, a known case of rheumatic heart disease who presented with breathlessness and dysphagia, and the cardiothoracic ratio on chest roentgenogram was 0.95. Echocardiography was suggestive of giant left atrium with a size of 19.4 x 18.3 cm, while magnetic resonance imaging revealed a size of 22.3 x 19.2 x 20.1 cm making it the largest left atrium to be reported in the literature.

<Learning objective: Giant left atrium is extremely rare in the current era, and if at all present, it is almost always secondary to rheumatic heart disease. These patients will have long duration of rheumatic heart disease, more chance of atrial fibrillation, compressive symptoms, and thromboembolism. Giant atrium is an indication for anticoagulation even if it is in sinus rhythm.>

Introduction

Left atrial enlargement is seen in a variety of cardiac conditions, including mitral valve disease, left ventricular failure, chronic atrial fibrillation, and left-to-right shunts seen in patent ductus arteriosus and ventricular septal defect, etc. [1]. Giant left atrium is typically found in patients with rheumatic mitral valve disease with severe mitral regurgitation (MR) or mixed stenotic with regurgitation [2]. These patients are usually symptomatic along with compressive symptoms such as dysphagia and hoarseness of voice [3]. Because of the early detection of rheumatic heart disease and treatment, giant atrium is rare in the current era. It is worth reporting this case because of the rarity of the giant left atrium, and this is the largest left atrium reported in the literature.

Case report

A 50-year-old woman was admitted with dyspnea of New York Heart Association class III, palpitation, and difficulty in swallowing for 3 months. She had been diagnosed with rheumatic heart disease 7 years earlier by echocardiography, which showed the mitral valve area of 1.2 cm², moderate MR, and a left atrial diameter of 4.3 cm. After that, she left the treatment and follow-up. The physical examination revealed pulse rate - 80/min, irregular, blood pressure 90/60 mmHg, her neck veins were distended, and grade III parasternal heave. There was soft and variable S1, wide split S2, mid-diastolic murmur, and grade 3/6 pansystolic murmur at apex.

Electrocardiogram showed atrial fibrillation with controlled ventricular rate and right axis deviation (Fig. 1). A chest radiograph (CXR) revealed massive cardiomegaly with cardio-thoracic ratio of 0.95, left ventricle type of apex, dilated left atrium reaching up to the right lateral chest wall with widened carina (Fig. 1). On the lateral view there was enlarged left atrium with posterior displacement of left main bronchus with upside-down 'V' shape of right and left bronchus (walking man sign).

Fig. 1.

(A) Electrocardiogram showing right axis deviation with atrial fibrillation, (B) chest X-ray posteroanterior view showing huge cardiomegaly with cardiothoracic ratio of 0.95 and also left atrium touches the right lateral wall with widened carinal angle, (C) lateral view showing enlarged left atrium with walking man sign.

Transthoracic echocardiography (ECHO) showed a hugely dilated left atrium of 19.4 x 18.3 cm in apical four-chamber and 17.8 cm in parasternal long-axis view. ECHO also showed a mitral valvular area of 1.32 cm², severe central MR with 2 jets, mild tricuspid regurgitation with right ventricular systolic pressure of 40 mmHg, compressed right atrium, right ventricle, and left ventricle (Fig. 2). Mean pressure gradient between left atrium and left ventricle was 8 mmHg. The patient had two MR jets so vena contracta was not validated however individual vena contracta of each jet was 0.5 cm and 0.7 cm with cumulative regurgitation jet fraction of 65%. The left ventricular ejection fraction was 60%.

Fig. 2.

Echocardiogram. (A) Apical four-chamber view showing left atrial size of 19.4 x 18.3 cm. (B) Short-axis view of the level of mitral valve with mitral valve area (MVA) of 1.32 cm². (C) Apical four-chamber view showing severe mitral regurgitation with regurgitant area of 42.9 cm². (D) Continuous wave Doppler at aortic valve showing no aortic stenosis.

LA, left atrium; RA, right atrium; RV, right ventricle.

Since the patient had dysphagia, cardiac magnetic resonance imaging (MRI) was done, which showed giant left atrium measuring 22.3 x 19.2 x 20.1 cm with volume 2896 ml. MRI also confirmed the findings of elevation of left bronchus and compression of the esophagus. Left atrium was anteriorly rotated and occupying the anterior of heart in position (Fig. 3).

Fig. 3.

Magnetic resonance imaging showing giant left atrium and compression of esophagus.

The patient was treated with diuretics, oral anticoagulation, and β-blocker. After stabilization, she was discharged, and she is waiting for a mitral valve replacement with left atrium reduction surgery.

Discussion

Left atrial anterior-posterior diameter of greater than 80 mm on transthoracic echocardiography is considered diagnostic of giant left atrium [4].

Although rheumatic heart disease with MR or mixed lesion represents the main cause of the giant left atrium, other etiologies such as mitral valve prolapse [5], hypertrophic cardiomyopathy [6], and cardiac amyloidosis [7] have also been reported.

Giant atrium was initially thought to occur because of the rheumatic process causing pancarditis [3]. However, pathological studies have found fibrosis with chronic inflammatory findings rather than Aschoff nodules [3] supporting long-standing chronic volume and pressure overload as etiology more than being a part of the rheumatic process.

Giant left atrium can cause intracardiac or extracardiac compression manifestations such as shortness of breath, dysphagia, palpitations, chest pain, swelling of the body, and thromboembolic events [3].

Patients with mitral valve disease with giant left atrium will have a long history of rheumatic heart disease, more risk of atrial fibrillation, more chance of compressive symptoms such as dysphagia, hoarseness of voice, and more chance of thromboembolism which is the major complication of giant left atrium. Therefore, giant left atrium is an indication for the initiation of anticoagulant therapy [3].

Hurst [3] defined a giant left atrium on CXR as “one that touches the right lateral side of the chest wall.” He considers the CXR diagnostic of a giant left atrium, when the left atrium touches the right lateral side of the chest wall. Giant left atrium should always be suspected in a patient with rheumatic mitral disease who develops right lung opacification on chest X-ray [3]. Echocardiogram will give the cause of giant atrium and diameter of the left atrium [1].

Additional imaging modalities such as MRI or computed tomography should be considered to precisely assess the size and its relationship with surrounding structures. The largest left atrial diameter measured in the literature was 20 x 22 cm in a patient with a prosthetic mitral valve [8]. To the best of our knowledge, this is the largest left atrium of size 22.3 x 19.2 x 20.1 cm to be reported in the literature to date.

Management of giant atrium is surgery, and the aim of surgery is to correct the mitral valve abnormalities, to treat compression manifestations, to prevent thromboembolism, and to revert atrial fibrillation to normal sinus rhythm. Mitral valve surgery with or without left atrium volume reduction is indicated in giant left atrium [9]. The main indication for volume reduction is the presence of intracardiac or extracardiac compressive symptoms. But some surgeons believe that successful mitral valve surgery alone will result in the eventual reduction of left atrial size as the volume and mean atrial pressure decline [9].

Declaration of Competing Interest

The authors declare that there is no conflict of interest.