A case of a 58-year-old woman with restrictive cardiomyopathy and unusual interatrial left-to-right shunt is presented. Transthoracic echocardiography suggested the coronary artery fistula draining into right atrium. Transoesophageal echocardiography revealed patent foramen ovale with concomitant left-to-right shunt. Increased pressure within the both enlarged atria caused the inefficiency of the valve of PFO and interatrial leak leading to 'acquired form' of an atrial septal defect.