Parachute mitral valve and mid-aortic syndrome – unusual associations of Alagille syndrome

Abstract

Background: Alagille syndrome (ALGS) is a multisystem disorder involving at least three systems among the liver, heart, skeleton, face, and eyes. Common cardiac associations include pulmonary artery stenosis/atresia, atrial septal defect (ASD), ventricular septal defect (VSD) and tetralogy of fallot (ToF). Coarctation of aorta (CoA), renal and intracranial arteries are commonly involved vessels in Alagille syndrome. We present two cases with rare cardiovascular manifestations of Alagille syndrome. Case description: Case 1: A 25-year-old female with a history of Alagille syndrome presented to the cardiologist office for progressive exertional dyspnoea, orthopnoea, and palpitations. She was tachycardiac on examination and had an apical diastolic rumble. A transthoracic echocardiogram (TTE) showed a left ventricular ejection fraction (LVEF) of 60% and parachute mitral valve (PMV) with severe mitral stenosis. A transoesophageal echocardiogram (TOE) showed insertion of chordae into the anterolateral papillary muscle, severe mitral stenosis with a valve area of 0.7 cm. She was referred to a congenital heart disease specialist and underwent robotic mitral valve replacement with improvement in her symptoms. Case 2: A 27-year-old female with known Alagille syndrome and resistant hypertension presented to the cardiologist office due to progressive exertional dyspnoea for a year. She was hypertensive and had a new 2/6 systolic ejection murmur along the left upper sternal border. TTE revealed an LVEF of 60% and pulmonary artery pressure of 19 mmHg. A CoA was suspected distal to the left subclavian artery due to a peak gradient of 38 mmHg. Cardiac magnetic resonance (CMR) imaging ruled out CoA, and diffuse narrowing of the descending thoracic aorta measuring 13–14 mm in diameter was noted. The patient was referred to a congenital heart disease specialist for further management. Conclusion: PMV presenting as mitral stenosis and mid-aortic syndrome are not commonly described anomalies in association with Alagille syndrome. TTE, TOE and CMR played a key role in diagnosis and management of these patients.