Lutembacher Syndrome : Case Report and Literature Review

The Lutembacher syndrome (LS) is a rare condition, defined as a combination of mitral stenosis and an ostium secundum atrial septal defect (ASD). Both defects, ASD and mitral stenosis, may be congenital or acquired, and present a number of hemodynamic repercussions according to: disease evolution time, ASD size, and severity of mitral valvopathy. We report a case of this syndrome in a young oligosymptomatic patient, but with well-established cardiovascular disorders.


Introduction
The Lutembacher syndrome (LS) is a rare condition, defined as a combination of mitral stenosis and an ostium secundum atrial septal defect (ASD).Both defects, ASD and mitral stenosis, may be congenital or acquired, and present a number of hemodynamic repercussions according to: disease evolution time, ASD size, and severity of mitral valvopathy.We report a case of this syndrome in a young oligosymptomatic patient, but with well-established cardiovascular disorders.

Case Report
Seventeen-year-old female patient, born and living in Espírito Santo -Brazil, previously healthy and asymptomatic.In September/2016, during physical activity at school, the patient had sudden dyspnea of moderate intensity, associated with intense sharp chest pain, lasting about 10 minutes, requiring interruption of the exercise.
After one (1) week of symptoms, she sought medical attention with a cardiologist.At physical examination, she was in good general condition, acyanotic, with respiratory auscultation without any disorders.Cardiac auscultation evidenced 3+/6+ systolic murmur more audible in the upper left sternal border, with fixed and wide split of the second sound.The precordium was hyperdynamic and it was possible to palpate right ventricular systolic impulses.Blood pressure 110/70 mmHg , heart rate 70 bpm, low amplitude and symmetrical peripheral pulses, no abnormalities in abdominal and lower limb examination.She had brought normal laboratory test results, such as hemogram, renal function, lipidogram and thyroid function.
Chest X-ray showed enlarged cardiac area and electrocardiography showed sinus rhythm with right axis deviation and overload of right chambers (Figure 1).
Transthoracic echocardiography was performed one month after the first consultation for diagnostic elucidation, which showed a 55% left ventricular ejection fraction, severe increase in right chambers (right ventricle with 56 mm basal, 44 mm mean and 78 mm longitudinal dimensions), ostium secundum atrial septal defect (ASD) measuring about 2.0 cm, with a large shunt from the left atrium to the right atrium.
Mitral valve with reduced opening, no calcification or significant thickening of cusps, average gradient of 11 mmHg and valvular area calculated by the planimetry of 1.3 cm², representing moderate to severe mitral valve stenosis of probable congenital etiology (Figure 2).The test also revealed pulmonary hypertension with pulmonary artery systolic pressure estimated at 50 mmHg, associated with pulmonary artery trunk dilatation, measuring approximately 3.7 cm without evidence of pulmonary valve stenosis or significant insufficiency.
The patient remained oligosymptomatic throughout this period, maintaining some sporadic episodes of dyspnea on exertion (functional class II), and non-specific chest pain.
Based on the clinical and imaging findings, Lutembacher Syndrome (LS) was diagnosed and the patient was referred for consultation for pediatric cardiac surgery.Despite efforts to provide adequate treatment and thorough explanations of disease progression and prognosis, the patient and her family chose to remain under clinical treatment and routine outpatient follow-up.However, she goes to outpatient clinics irregularly, not properly continuing clinical treatment.

Literature Review
The Lutembacher Syndrome (LS) is a very rare disease whose incidence in a study published in the American Heart Journal in 1997 was 0.001/1,000,000. 1It was first described in 1865 by Martineau, and revised by Lutembacher in 1916. 2 It consists of a combination of ostium secundum atrial septal defect and mitral stenosis.¹Opinions differ as to the type of mitral lesion that should be included in this syndrome.In some papers, it is simply described as acquired mitral stenosis.Today, however, the recognition of LS includes congenital or acquired disorders, both in mitral stenosis and in atrial septal defect (ASD).²This defect in LS may also be iatrogenic, secondary to transeptal puncture during mitral valvuloplasty.³A study published in 2016 in India, a country with a high prevalence of rheumatic disease, assessed 44 autopsies of patients with Lutembacher syndrome and 54.5% of patients had non-rheumatic mitral valve disease. 4e hemodynamic repercussion resulting from this syndrome depends on the ASD size and the severity of the valve stenosis, which may lead to varying degrees of pulmonary hypertension, right chamber dilatation and tricuspid valve failure.Generally, since right ventricular compliance is lower, blood flow goes through the left atrial septal defect into the right atrium, leading to dilation and progressive dysfunction of the right chambers, as well as reduced blood flow to the left ventricle.Thus, in general, there will be no pulmonary congestion commonly found in isolated mitral stenosis,² and   clinical presentations will most often be due to ASD, with variations in signs and symptoms depending on the ASD size.ASD in LS generally has a diameter greater than 1.5 cm, causing a severe left-right shunt, which can progress with progressive pulmonary hypertension and development of Eisenmenger's syndrome.³Patients commonly report fatigue, exercise intolerance, palpitations, and are even more predisposed to develop atrial arrhythmias, of which atrial fibrillation (AF) is the most frequent one.³Physical examination shows lower amplitude arterial pulses with regular rhythm and high jugular venous pulse (even in the absence of right heart failure, as well as absence of pulmonary hypertension).In addition to the classic findings of mitral stenosis (hyperphonesis of the first heart sound, diastolic rhythm and opening click), it is common to hear the fixed split of the second heart sound (B2), which is typical of interatrial septal defect, as well as a proto or meso-diastolic murmur.³As a workup, thorax radiography may show cardiomegaly and, occasionally, signs of pulmonary congestion.Electrocardiogram (ECG) may reveal right bundle branch block, right ventricular hypertrophy with right chamber overload and atrial fibrillation may be observed in some cases.Echocardiography is the gold standard method for diagnosing LS, with the benefit of not being invasive and widely available, as well as accurate for the evaluation of ASD and mitral valvopathy with its different severities. 5 : Imagem cardiovasc.2018;31(2):107-109

Figure 1 -
Figure 1 -Electrocardiography (A) showing sinus rhythm with right axis deviation and overload of right chambers.In B, chest X-ray with increased cardiothoracic index, bulging of the pulmonary artery trunk and obliteration of the retrosternal fat (finding compatible with enlarged right ventricle).

Figure 2 -
Figure 2 -Transthoracic echocardiogram showing in A and B an ostium secundum atrial septal defect with LA → RA flow.In C, swirling flow of mitral stenosis, and in D, overload of right chambers.RA: right atrium; LV: left ventricle; RV: right ventricle; LV: left ventricle; ASD: atrial septal defect.