INTRODUCTION: Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital defect that may not clinically manifest until adulthood. The increased pulmonary venous flow associated with PAPVC can eventually lead to dyspnea on exertion, atrial arrhythmias, pulmonary hypertension (PH), and right-sided heart failure (RHF). Most cases of PAPVC are associated with a concomitant atrial septal defect (ASD) and rarely present in isolation with an intact atrial septum. We report an unusual case of a patient presenting with PH and RHF who was found to have isolated PAPVC involving multiple right pulmonary veins with an intact atrial septum.
CASE PRESENTATION: A 33 year-old male with no past medical history presented to the emergency room with recurrent palpitations and was found to be in atrial flutter with rapid ventricular rate. He also endorsed worsening dyspnea, declining exercise tolerance, and progressive lower extremity swelling. On initial presentation, notable findings included a HR of 150-230; BP of 89/52; RR 20; arterial oxygen saturation 94% on room air; a right ventricle heave; increased jugular venous distension; and lower extremity edema. Rate control was achieved with the initiation of beta-blockers and digoxin; he was started on systemic anticoagulation and received aggressive diuresis. Electrocardiogram showed atrial flutter with right ventricular hypertrophy and right axis deviation. Transthoracic echocardiogram revealed a severely dilated right atrium (RA) and right ventricle (RV), severely reduced RV systolic function, and an estimated pulmonary artery (PA) systolic pressure of 60 mm Hg. Additionally, transesophageal echocardiography did not reveal intracardiac shunts or septal defects. Simultaneous right (RHC) and left heart catheterization (LHC) were performed under fluoroscopic guidance. Notable findings on RHC included the following pressures in mmHg: PA 65/36; pulmonary capillary wedge (PCWP) 21; RA 23; RV 65/22. The most notable finding on LHC was a left ventricular end-diastolic pressure (LVEDP) of 11 mmHg. To further investigate the discrepancy between the PCWP and LVEDP, a CT pulmonary angiogram was obtained. This revealed a left to right shunt—the right superior pulmonary vein entered the superior vena cava (SVC) and two pulmonary veins draining the right middle lobe entered the SVC and RA. Repeat RHC with oxygen sampling revealed an oxygen step-up of 53.4% to 64.3% from the proximal SVC to the RA-SVC junction, and a pulmonary to systemic blood flow ratio (Qp:Qs) ratio of 1.27. These findings were consistent with PAPVC involving three right pulmonary veins, contributing to PH and RHF. The patient was referred to cardiothoracic surgery for surgical correction of the PAPVC.
DISCUSSION: The unique features of this case—including the finding of isolated PAPVC with an intact atrial septum—were discovered during this patient’s investigation for PH and RHF. The discrepancy between the PCWP and LVEDP led to the consideration of unusual vascular malformations. CT pulmonary angiography then led to the revelation of anomalous pulmonary venous drainage, which was further confirmed by repeat RHC with oxygen saturation sampling. PAPVC is an extremely rare congenital vascular anomaly. An associated ASD of the sinus venosus type is found 80-90% of cases of PAPVC; rarely is the atrial septum found to be intact. An exceedingly low number of cases involve three or more anomalous pulmonary veins. The defect becomes clinically significant when >50% of the pulmonary venous flow anomalously returns to the right side. The treatment of symptomatic PAPVC is almost always surgical, often via techniques that redirect the anomalous veins to the left atrium.
CONCLUSIONS: This case represents a rare finding of isolated PAPVC with intact atrial septum leading to PH and RHF in an adult. The diagnosis of this condition can represent a clinical conundrum, highlighting the importance of a multidisciplinary approach in order to establish a correct diagnosis.
Reference #1 Geva T. Anomalies of the pulmonary veins. Moss and Adams’ heart disease in infants, children, and adolescents. Philadelphia, PA: LWW 2001.736-772
Reference #2 Ammash NM et al. PAPVC: diagnosis by TEE. J Am Coll Cardiol 1997;29:1351-1358
DISCLOSURE: The following authors have nothing to disclose: Richie Rana, David Padua, Rick Tennant, Greg Bierer, Jeanne Wallace, Nader Kamangar
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