Platypnea-Orthodeoxia Syndrome after Transcatheter Aortic Valve Implantation.

Andrew K Roy,Thierry Lefèvre,Fadi J Sawaya,Marco Spaziano,Jerome Garot,Antoinette Neylon

doi:10.1155/2016/6954121

Abstract

Progressive dyspnea and hypoxaemia in the subacute phase after transcatheter aortic valve implantation (TAVI) are uncommon and warrant immediate assessment of valve and prosthesis leaflet function to exclude thrombosis, as well as investigation for other causes related to the procedure, such as left ventricular dysfunction, pulmonary embolism, and respiratory sepsis. In this case, we report the observation of a patient presenting two weeks after TAVI with arterial hypoxaemia in an upright position, relieved by lying flat, and coupled with an intracardiac shunt detected on echocardiography in the absence of pulmonary hypertension, raising the suspicion of Platypnea-Orthodeoxia Syndrome (POS). Invasive intracardiac haemodynamic assessment showed a significant right-to-left shunt (Qp/Qs = 0.74), which confirmed the diagnosis, with subsequent closure of the intracardiac defect resulting in immediate relief of symptoms and hypoxaemia. To our knowledge, this is the first reported case of an interatrial defect and shunt causing Platypnea-Orthodeoxia Syndrome after transcatheter aortic valve implantation, resolved by percutaneous device closure.

Highlights

Dyspnea is the commonest presenting symptom for severe calcific aortic stenosis, occurring in approximately 60–70% of patients who are considered at high or prohibitive risk for surgery but eligible for transcatheter aortic valve implantation (TAVI) [1]
Platypnea-Orthodeoxia Syndrome (POS) is an uncommon clinical cause of dyspnea and hypoxaemia associated with interatrial communications and functional alterations required to preferentially shunt venous return towards the septal defect [2]
It is associated with a number of cardiac, pulmonary, or abdominal conditions and, given the potentially reversible nature, should always be considered when hypoxaemia with postural features remains unresponsive to standard oxygen therapy [3]

Summary

Introduction

Dyspnea is the commonest presenting symptom for severe calcific aortic stenosis, occurring in approximately 60–70% of patients who are considered at high or prohibitive risk for surgery but eligible for TAVI [1]. To determine suitability for TAVI under conscious sedation, patients will typically undergo a number of investigations including transthoracic echocardiography, coronary angiography, thoracic multidetector computed tomography, and assessment of the peripheral vasculature for iliofemoral patency During this evaluation, any other reversible cardiac causes of dyspnea, such as severe coexisting proximal coronary artery disease or congestive heart failure, will be detected and treated with the aim of minimizing periprocedural events and ensuring an optimal and durable response to TAVI. The development of acute or subacute dyspnea in the initial period after TAVI is a serious concern, prompting the clinician to immediately consider mechanical aortic prosthesis dysfunction, as a result of thrombosis or infection, along with other more common causes of dyspnea such as congestive heart failure, pulmonary embolism, and respiratory sepsis In this case report of new onset dyspnea one week after TAVI, the observation of postural hypoxaemia, normal aortic prosthesis function, and clear evidence of a new intracardiac shunt on echocardiography prompted us to consider the rare clinical Platypnea-Orthodeoxia Syndrome as a cause for this patient’s symptoms

Case Presentation

Discussion