Abnormal inferior vena cava (IVC) drainage into the left atrium (LA) is an infrequent complication after surgical closure of an atrial septal defect (ASD). We present the case of a 45-year-old woman, with surgical closure of an ASD 8 years before, who consulted for exertional dyspnea and cyanosis. Transthoracic and transesophageal echocardiography showed no residual shunt after contrast administration in both arms, and thoracic CT scan and pulmonary ventilation / perfusion gammagraphy were normal. In the presence of signs strongly suggesting a right-to-left shunt, we decided to complete the study with a CMR,which revealed an anomalous systemic drainage with IVC draining into the LA with right-to-left shunt. Surgical repair of the abnormal IVC drainage was successfully performed. During the intervention cardiac surgeons found a repaired ASD located in the lower portion of the interatrial septum, a large Eustachian valve, which are anatomical features which can sometimes lead to an erroneous suture causing the drainage of the IVC towards the LA. In conclusion, it is essential to carry out an extensive search for possible residual anatomical shunts in patients who undergo surgery and develop hypoxia. The reported case underlines the importance of being aware of this possible complication of the closure of an ASD and highlights that the absence of passage of agitated saline contrast to left chambers with conventional injection by the arms does not rule out any residual shunt, recommending its administration by the lower limbs, as well as the CMR for the definitive diagnosis. Abstract 1108 Figure. CMR imaging 3D reconstruction

A 43-year-old male was brought to the emergency department due to a recovered sudden cardiac arrest that occurred while performing physical exercise of moderate intensity. The patient was admitted in a coronary care unit and performed complementary tests to rule out immediate causes of cardiac arrest electrocardiogram showed sinus rhythm, no repolarization abnormalities and normal QTc interval. Echocardiogram revealed no evidence of cardiac tamponade, massive pulmonary embolism (PE), ventricular dysfunction or valvular heart disease. Absence of pneumothorax in chest X-ray. Arterial blood gas test revealed a high lactate concentration with other parameters in normal range. Cerebral tomography showed absence of an acute hemorrhagic event. To continue with the study an emergent coronarography was performed showing epicardial arteries with no significant obstructive coronary artery disease associated with an anomalous origin of left main coronary artery in the right sinus of Valsalva with possible interarterial course. Coronary tomography confirmed the origin of the right coronary artery and the left main coronary artery in the right sinus of Valsalva with an interarterial course, proceeding to the reconstruction of the images with the volume rendering (VR) technique (Figure 1). Congenital anomalies of the coronary arteries are a rare but life-threatening condition. Most coronary abnormalities are asymptomatic and follow a benign course, however, in some cases they present with ischemic symptoms, heart failure, myocardial infarction, syncope or sudden death. The anomalous origin of the left main coronary artery in the right sinus of Valsalva can cause myocardial ischemia and should be ruled out in young patients who present sudden cardiac arrest induced by physical exercise. Abstract P269 Figure 1

Left atrial appendage aneurysm is an infrequent cardiac malformation, with less than 150 cases reported in the literature. It is a congenital anomaly in the majority of cases, related to a dysplasia of pectinate muscles and atrial muscle bands, which tends to grow with age. At the present time, and despite of being not considered in current guidelines, surgical resection is the standard of treatment in the current literature, even in asymptomatic cases, based on cardiovascular morbidity and mortality by predisposing to atrial tachyarrhythmia, thromboembolism, and other rare conditions as coronary or left ventricular compression and rupture of the aneurysm. We report the case of a 53-year-old male patient presenting an episode of supraventricular paroxysmal tachycardia with the casual finding of a mysterious cavity in the transthoracic echocardiography. We found out the presence of a 50 mm cavity adjacent to the left atrium and left ventricle, with a bidirectional blood flow between the left atrium and the cavity when applying Doppler color and with contrast echocardiography. Given this finding, several differential diagnosis had to be considered, including vascular and structural disorders. In order to clarify the diagnosis, a cardiac magnetic resonance was performed. It revealed the presence of a huge aneurysm of the left atrial appendage (50 x 53 mm) causing a mild compression of the left ventricle, with no thrombus and no other significant findings. Due to its size, the compression of the left ventricle and the history of atrial arrhythmia we decided to manage it with an invasive approach by performing a middle thoracotomy, in order to prevent potentially serious complications. Abstract 1112 Figure. CMR 3D reconstruction; echocardiography