Echocardiographic diagnosis of coronary artery fistula in both dizygotic twin brothers: environmental mechanism?Caputo, Salvatore; Sorice, Nunziatina; Sansone, Renato; Simeone, Domenico; Caruso, Vincenzo; Russo, Rocco; Cicchella, Nicola; Izzo, Annamaria; Saviano, Carmen; Casani, Antonella; Ciampi, Quirino; Villari, BrunoJournal of Cardiovascular Medicine: May 2017 - Volume 18 - Issue 5 - p 378–380 doi: 10.2459/JCM.0b013e328336b5b7 Case reports Abstract Author Information A congenital coronary artery fistula (CAF) is a rare form of heart disease in which a coronary artery and a cardiac chamber or another vascular structure communicate. CAF could worsen ventricular perfusion and function, favoring ventricular ischemia and arrhythmias. To our knowledge, this is the first report of CAF, draining in the pulmonary artery, in two asymptomatic dizygotic twin brothers, diagnosed by echocardiography. Dizygotic twins are siblings with different genes exposed to the same environmental experience during the pregnancy. The occurrence of CAF (with similar instrumental findings) in both twin brothers could depend on a poorly identified environmental factor during pregnancy. aDivision of Cardiology, Fatebenefratelli Hospital bPediatric Practitioner, Benevento, Italy Correspondence to Salvatore Caputo, MD, Giovan Battista Piranesi 1/E, 82100, Benevento, Italy Tel: +39 082 477 1468; fax: +39 08 244 7935; e-mail: firstname.lastname@example.org Received 5 October, 2009 Revised 1 November, 2009 Accepted 15 December, 2009 © 2017 Italian Federation of Cardiology. All rights reserved.