325 Left main coronary artery compression due to dilatation of the main pulmonary artery in patients with pulmonary hypertension: treatment and long-term follow-up Compresión del tronco de la arteria coronaria izquierda por la dilatación de la arteria pulmonar principal en pacientes con hipertensión pulmonar: tratamiento y seguimiento a largo plazo Juan M. Farina*, Guillermina Sorasio, Víctor Darú, and Adrián J. Lescano Department of Cardiology, Red de Clínicas de Santa Clara. Buenos Aires, Argentina SCIENTIFIC LETTER Correspondence: *Juan M. Farina E-mail: juan.farina@gmail.com Available online: 04-12-2020 Arch Cardiol Mex (Eng). 2020;90(3):325-328 www.archivoscardiologia.com Date of reception: 13-08-2019 Date of acceptance: 20-01-2020 DOI: 10.24875/ACME.M20000139 A 56-year-old female patient who had been diag- nosed with idiopathic pulmonary hypertension 3 years before the consultation presented to the emergency department referring a 2-week history of dyspnea and angina in functional Class III. Signs of right heart failure were confirmed (lower limb edema, mild bilateral pleural effusion, and positive hepatojugular reflux) at admis- sion, as well as an increased intensity of second cardi- ac sound, and a pulmonary focus ejection murmur. Baseline diagnostic workup included an electrocardio- gram that showed right ventricular hypertrophy and complete right bundle branch block. Doppler echocar- diogram revealed right chambers dilation with a mild depression in right ventricular systolic function and a moderate tricuspid regurgitation with a peak velocity of 4.52 m/s, the estimated pulmonary artery systolic pres- sure was 90 mmHg (based on an 82 mmHg gradient between right ventricle and atrium added to a right atrium pressure of 8 mmHg determined by inferior vena cava diameter and collapse). In addition, this method allowed the suspicion of the main coronary artery ex- trinsic compression as the cause of angina due to a severe dilation of the main pulmonary artery (55 mm), and of its main branches, was found 1 . Because of this suspicion, a chest computed tomography (CT) angiography was performed; it confirmed the severe dilation of the pulmonary artery (54 mm in this case by this method) and showed an abnormal trajectory of the left main coronary artery, with critical reduction of its lumen, decreased distance between it and the pulmo- nary artery, and a very narrow angle with the left sinus of Valsalva (Fig. 1A) 2 . After assuming extrinsic com- pression by the pulmonary artery, a coronary angiogra- phy was performed for initially diagnostic and potentially therapeutic purposes. It revealed a proximal severe obstruction of the left main coronary artery, with TIMI (thrombolysis in myocardial infarction) 2 flow, and an almost parallel path to the left sinus of Valsalva due to the dislocation generated by the compression (Fig. 1B). For a better definition of the lesion intravascular, ultra- sound was used; it showed an absence of atheroma- tous plaques and confirmed the severe reduction of proximal left main coronary artery diameter and the extrinsic nature of the obstruction (Fig. 1C) 3 . A 4.5 × 20 mm drug-eluting stent was placed in the left main coronary artery, without complications. The pa- tient evolved favorably, and annual follow-up with chest CT angiography was carried out, with no evidence of complications 3 years after the stent placement. 2604-7063 / © 2020 Instituto Nacional de Cardiología Ignacio Chávez. Published by Permanyer. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). No part of this publication may be reproduced or photocopying without the prior written permission of the publisher. © Permanyer 2020