INTRODUCTION: Partial anomalous pulmonary venous drainage (PAPVD) is very rare condition due to failure of the embryological pulmonary venous confluence to fuse with the forming left atrium. As opposed to total pulmonary anomalous venous drainage, PAPVD can go undiagnosed until adulthood. We here present a case of young adult with atypical chest pain, who was eventually diagnosed to have PAPVD.
CASE PRESENTATION: 24-year-old white male in active military duty presented to the cardiology clinic for evaluation of atypical chest pain. An exercise stress echocardiogram was negative for ischemia at twelve minutes. TTE showed normal left ventricular size and function but suggested moderate dilatation of the right atrium (RA) and right ventricle (RV). Cardiac magnetic resonance imaging (CMR) was performed to evaluate the etiology of right heart dilatation. CMR revealed moderate dilatation of the RA/RV with mild bowing of the interventricular septum during diastole consistent with right sided volume overload. There was no evidence of atrial septal or sinus venosus defect. CMR also revealed partial anomalous pulmonary venous drainage (PAPVD) with drainage of right upper and lower pulmonary veins into the SVC via the azygous vein resulting in a significant left to right shunt. Qp:Qs was calculated to be 1.6. On further questioning, the patient mentioned that he seemed to have a relative effort intolerance compared to his peers and frequent pulmonary infections during childhood. ECG showed incomplete right bundle branch block. Right heart catheterization was then performed to confirm the hemodynamics of the anomalous venous connection. Superior vena cava saturation at level before the azygos vein entry was 70%, while SVC saturation after azygos vein was 91%. Azygos vein saturation was 96%. This confirmed the CMR findings of a left to right shunt with oxygenated blood from the two right pulmonary veins draining into the SVC via the azygos vein. Calculated Qp/Qs by right heart catheterization was 1.5. A cardiac CT was performed to get a better 3D perspective of the PAPVD prior to surgery. The patient underwent surgical correction with creation of an autologous pericardial baffle within the SVC connecting azygos vein to the left atrium through a surgically created atrial septal defect. The patient had an excellent post-operative recovery and reported significant improvement.
DISCUSSIONS: Traditionally echocardiography and conventional angiography are frequently used for the diagnosis of PAPVD. However, definitive diagnosis of PAPVD may be difficult with echocardiography in adults due to the limited acoustic windows of right side of the heart. At present, angiography is considered the standard imaging modality for the diagnosis of anomalous pulmonary veins, however it is invasive, and visualization of the veins may be difficult because of the dilution of hand-injected angiographic contrast material. Moreover, given the fact incidence of this entity is so low, non-invasive modalities like CT angiogram and Cardiac myocardial resonance imaging (CMR), as in our case, might be better initial diagnostic modality. CMR offers a several unique advantages i.e., large field of view and excellent anatomic delineation without contrast material injection or ionizing radiation. In addition, CMR can depict atrial septal defects which are frequently associated with PAPVD (1).
CONCLUSION: Multi-modality imaging i.e., CMR and CT angiogram along with three dimensional reconstructions can be very useful in diagnosis of PAPVD and associated abnormalities like ASD. CMR should be considered as the initial diagnostic modality of choice for patient with suspected PAPVD.
DISCLOSURE: Rahul Shekhar, No Financial Disclosure Information; No Product/Research Disclosure Information