History, current illness and physical examination
82-year-old female patient with a history of arterial hypertension, hypercholesterolemia, stage II chronic kidney disease, hepatitis C virus positive, atrial fibrillation of one year's evolution.
On regular treatment with acenocoumarol, doxazosin 4 mg one tablet a day, diltiazem 120 mg one tablet a day, furosemide 40 mg one tablet a day, pitavastatin 2 mg and mirtazapine 30 mg. Previously asymptomatic, the patient was referred to our hospital for progressive dyspnoea of two weeks' duration until she became resting in the last few days, with significant abdominal distension and oedematisation of the lower limbs. She had no chest pain or palpitations. She had symptoms of non-specific dizziness, sometimes spinning, which intensified with episodes of dyspnoea at rest.
On physical examination, the patient was in good general condition, conscious, oriented and cooperative. Well hydrated and perfused, tachypnoeic at rest and unable to tolerate decubitus. Afebrile. Blood pressure of 111/50. Heart rate of 100 bpm. Oxygen saturation at room air of 91%. Cardiac auscultation with irregular sounds and a panfocal systolic murmur II-III/VI. Pulmonary auscultation with global hypoventilation and semiology of right pleural effusion and bibasal crackles. Abdomen globular and distended, not painful on palpation and with semiology of minimal ascites, signs of dubious positive surge. No signs of jugular ingurgitation. Tibio-malleolar oedema up to the knees with fovea +++/++++.

Complementary tests
CBC on admission: glucose 1.533, urea 233, creatinine 5.28, K 7.9 mEq/L, Na 114, Cl 68, Ca 7.5, Mg 2.3, Ca ion 0.83, EAB pH 7.07, pCO2 21 mmHg, pO2 113, HCO3 6.1, EB -24, SpaO2 96%, Hb 8.2, HTO 26.8%, leukocytes 15.520, neutrophils 92.7%, platelets 283,000, PT 68%, aPTT 31.7 secs, fibrinogen 282, INR 1.28, CK 169, CKMB 5.4, TnTUS 93.95, ANION GAP 114-68+ 6.1= 39.9. ʟʟ
Electrocardiogram: atrial fibrillation with mean ventricular response at 100 bpm. QRS 120 ms with morphology of complete right bundle branch block and secondary repolarisation disturbances.
Chest X-ray: cardiomegaly. Bilateral pleural effusion predominantly on the right. Left costophrenic sinus impingement. Interstitial oedema in butterfly wings.
Urgent laboratory findings: creatinine 1.54 mg/dL, urea 71 mg/dL, sodium 141 mmol/L, potassium 4 mmol/L, haemoglobin 10.8 g/dL, INR 6.91.
Baseline arterial blood gas: PH 7.40, PO2 56.7 mmHg, PCo2 50.7 mmHg, HCO3 30.50.
Transthoracic echocardiography: moderate left ventricular wall hypertrophy (13 mm; 12 mm) with preserved left ventricular systolic function (LVEF Simpson 63%). Biauricular dilatation. Mild mitral regurgitation II/IV. Significant coronary sinus dilatation. Significant dilatation of the left coronary artery (at the level of the ostium 12 mm) with fistulous trajectory in a mosaic pattern suggestive of coronary fistula that seems to be directed to the left atrial appendage, but probably drains into the coronary sinus given the significant dilatation of the same. Dilatation of right chambers with depressed contractility (TAPSE: 14 mm). Moderate-severe tricuspid insufficiency (III/IV) with PAPS of 48 mmHg. Qp/Qs 1.49.
Cardiac MRI: left ventricular septal hypertrophy (16 mm) with preserved left ventricular volumes and function. Right ventricle at the high limit of normality (VTDVD 92 ml/m2; VTSVD 49 ml/m2) with mild depression of right ventricular function. Flattening of the interventricular septum. Very dilated atria (left atrium 43 cm2; right atrium 36 cm2). Tubular portion of ascending aorta dilated. Pulmonary trunk and both branches dilated (pulmonary trunk 36 mm, left pulmonary artery 23 mm and right pulmonary artery 33 mm). Dilated inferior vena cava (26 mm) without inspiratory collapse. Dilated left main trunk. Anterior descending artery of normal size. Circumflex artery with large dilatation along its entire length (10-14 mm) and saccular aneurysm in the distal portion of 3.5 cm in diameter with drainage into the coronary sinus. No communication with pulmonary vessels was observed.
Coronography: large aneurysmal dilatation of the left coronary trunk from the origin that continues with the circumflex artery very aneurysmal and with great tortuosity. Large aneurysm dependent on the marginal branch. The circumflex artery flows into the right coronary artery through the very dilated coronary sinus. Rest of coronary arteries without findings.
Multislice CT angiography: dilatation of the circumflex artery with saccular aneurysm in its distal portion and drainage in the coronary sinus.

Clinical evolution
Diuretic treatment and poor tolerance to vasodilator and beta-blocker treatment, so initial management was restricted to intravenous diuretic infusion with oral potassium and oral ACE inhibitors, as well as anticoagulation. The patient had symptoms of dizziness and significant asthenia, which made it necessary to start beta-blockers progressively, starting with minimal doses, and finally achieving good tolerance.
She presented several episodes of atrial fibrillation with ventricular response at 170 bpm symptomatic with clinical dyspnoea and non-specific dizziness, but with good haemodynamic response, which meant that, given the poor initial tolerance of the beta-blockers, digoxin had to be associated, despite the renal failure, with correct control of renal function, which did not worsen. Finally, significant improvement in congestive symptoms was achieved with diuretics, heart rate control with digoxin and beta-blockers, as well as control of blood pressure. After performing the complementary examinations, the therapeutic possibilities for the patient were discussed in a joint cardiology and cardiovascular surgery session, presenting a surgical risk of 15.9% according to the logistic score. After proposing surgery to the patient and her relatives, given the patient's age and current situation, with significant clinical improvement, they decided on an initially conservative management, considering the surgical option at a later stage if the patient worsened again at home. After 12 days in the cardiology ward, the patient was discharged home with diuretic treatment, beta-blocker, digoxin for three days a week, anticoagulation and antihypertensive treatment. The patient was seen in outpatient clinics and was clinically stable with no new episodes of heart failure. Three months after discharge, while at home, she presented an episode of sudden death that triggered the patient's death, the origin of this event being unknown.

Diagnosis
Debut of heart failure.
Symptomatic left coronary fistula in an elderly patient of probable congenital origin.
