Abstract 15284: Blessing in Disguise: Absent Pulmonary Valve in an Adult Without Ventricular Septal Defect

Abstract

Introduction: Congenital absence of the pulmonary valve (APV) is a rare cardiac malformation. Adults with this condition generally need corrective surgery before the age of 20. We report a unique case of an isolated APV in a Jamaican female who remained asymptomatic until presentation at the age of 39. Case: Patient presented to a local cardiologist with recent onset of NYHA II symptoms and atrial fibrillation. Her cardiovascular exam revealed a right ventricular (RV) heave , III/VI holosystolic murmur along right lower sternal border, III/VI early diastolic murmur in pulmonic area, no clinical signs of right heart failure (RHF). Diagnostics: An echocardiogram showed dilated RV outflow tract, APV, dilated main pulmonary artery (MPA) and severe pulmonary regurgitation (PR) (Figure 1A). RV size and function were quantified with cardiac MRI demonstrating RV end diastolic volume: 340 ml/m2 (Z score 11.9) and RVEF: 46% ( Z score -2.8) (Figure 1B). Flow data of the MPA showed a flow of 4.9L/min, severe PR with a regurgitant fraction of 48% and Qp/Qs of 1.1:1 (Figure 1C). Right heart catheterization demonstrated equalization of diastolic pressure in both RV and PA (52/10 mm Hg) diagnostic of free PR. (Figure 1D). Mean PA pressure was 24 mm Hg and pulmonary vascular resistance was 3 wu. On cardiopulmonary stress testing, the patient completed 10.6 METS, achieving a peak VO2 of 18.5 ml/kg/min at RER 1.1. Discussion: APV is commonly categorized as with or without ventricular septal defect (VSD). APV with VSD is commonly associated with tetralogy of Fallot (TOF). The distinguishing features from TOF are: unobstructed RV infundibulum and aneurysmally dilated PA. APV in its severe form presents in infancy with severe respiratory distress from bronchial obstruction caused by massively dilated PAs. Isolated APV (non VSD type) is a rare variant. Our report is the first in literature to illustrate isolated APV in an asymptomatic adult approaching the fourth decade of her life.