HISTORY, CURRENT ILLNESS AND PHYSICAL EXAMINATION

History
43-year-old woman, with the following history: No known drug allergies. No known toxic habits or cardiovascular risk factors. Iron deficiency anaemia on intermittent treatment with oral iron. Anxiety-depressive syndrome, on anxiolytic treatment on demand. No family history of heart disease or early cardiovascular disease. Usual medication: folic acid 5 mg/24 h, lorazepam 1 mg (on demand).

Current illness
Consultation due to an episode of oppressive central thoracic pain, with accompanying vegetative symptoms, which started abruptly while standing up while working in a kitchen at high temperature and associated with a great feeling of stress. On arrival at the hospital, with progressive clinical improvement, no electrocardiographic alterations suggestive of ischaemia or mobilisation of myocardial damage enzymes were recorded. He denied previous history of angina, palpitations, syncope or presyncope. He reported progressive dyspnoea on moderate exertion of about 6 months' duration, without orthopnoea, oedema or reduced diuresis. Finally, it was decided to admit him to the cardiology department for further tests.

Physical examination
Asymptomatic, normal colour, well perfused, without jugular ingurgitation or hepatojugular reflux.

Blood pressure (BP) 110/60 mmHg, heart rate (HR) 80 bpm. Eupneic at basal saturation 99%. On auscultation, rhythmic heart tones, with systolic murmur II/VI panfocal but predominantly pulmonary, radiating to the carotids and more noticeably to the interscapular region. Abdomen: normal examination, with no pathological findings. Radial and pedial pulses symmetrically preserved. Absence of oedema.

COMPLEMENTARY TESTS
Electrocardiogram (ECG): RS at 57 bpm, normal axis, without atrioventricular (AV) or intraventricular conduction disorders, without repolarisation disorders.

Chest X-ray: cardiothoracic index (CTI) at the upper limit of normality, with an increase in the pulmonary vascular pattern.

Laboratory tests:
Initial blood tests (ED): hypochromic microcytic anaemia with haemoglobin 9.3 g/dl (similar to previous ones), MCV 84 fl, MCH 25.9 pg, rest of haemogram normal. Renal function, hepatobiliary profile and ions normal. Creatine phosphokinase normal. TnT 9-16 ng/l.

Analytical studies during admission (summary):
Blood count: haemoglobin stable at around 10 g/dl, the rest without alterations.
Deficiency profile: serum iron 67.20 g/dl, IST 19%, ferritin 13.70 g/l, transferrin 282.40 mg/dl, vitB12 normal, folic acid 2.4 g/l.
Biochemistry: renal function ions and liver function markers normal. Metabolic and other profile: TSH normal. HbA1C 5.8%.
Lipid profile normal. Normal acute phase reactants. Negative autoimmunity markers (RF, ANA, ANCA, C3, C4). ProBNP 167 pg/ml.

Transthoracic echocardiogram: left ventricle (LV) slightly dilated by volumes (DTDVI 52 mm, BP vol 165 ml), not hypertrophied. Dilated left atrium indexed to body surface area (44 ml/m2). Normal right chambers. Aorta of normal calibre and flow in its accessible sections. Absence of significant valvulopathies. No evidence of pulmonary hypertension. An anomalous filling jet is visualised in the left atrium, eccentric, which crosses the interatrial septum and reaches the mitral valve, continuous, with a Vmax of 3.4 m/s. Normal LV systolic and diastolic function, without contractility alterations. Normofunctioning right ventricle. No pericardial effusion or other findings. Contrast-enhanced CT angiography of coronary arteries and aorta: coronary arteries normal, without lesions. Fistula from the descending thoracic aorta to the left atrium, with saccular dilatation of the right posterior wall. Cardiac magnetic resonance (CMR): LV of normal diameter and morphology, with indexed end-diastolic volume of 78 ml/m2 (slightly dilated). Preserved LVEF, without segmental alterations of contractility. In cine sequences there was an evident aorto-atrial fistula (very fine jet at the level of the roof of the left atrium), the rest of the study with no significant findings.

CLINICAL EVOLUTION
Given the clinical data and initial complementary tests, the probability of ischaemic heart disease was considered low. However, given the exploratory findings, congenital heart disease was suspected, and the echocardiographic study showed an anomalous filling jet in the left atrium. Angio-CT of the coronary arteries was requested, ruling out arteriosclerotic disease, but a fistulous tract of saccular morphology was found between the descending thoracic aorta and the left atrium, with a suspected genetic origin in the absence of surgical history, trauma, or semiology compatible with current or previous endocarditis. During her admission she remained asymptomatic and the single episode of chest pain was attributed to an anxiety crisis, as the location of the fistulous tract did not justify in this case a possible coronary steal phenomenon. The study was completed on an outpatient basis with CMR, confirming the findings already described by echocardiogram and coronary CT, with data of incipient remodelling of the left chambers (dilatation and hyperflow). For this reason, a consensus was reached at a medical-surgical meeting on endovascular repair by means of percutaneous implantation of a thoracic aortic stent, which was carried out without complications, with good sealing of the leak in the control angiography.

DIAGNOSIS
Chest pain of multifactorial cause: anxiety crisis, hyperdynamic state. Angiographically normal coronary arteries by CT angiography.
Left aorto-atrial fistula with evidence of incipient remodelling of the left cavities (dilatation and hyperflow).
