Right-to-left interatrial shunt after pneumonectomy

Patent Foramen Ovale and Hypoxemia

Patent foramen ovale (PFO), an embryonic remnant of the fetal circulation, is present in 20-25% of adults. Although recent observational studies and clinical trials have established the link between PFO-mediated right-to-left shunting with cryptogenic stroke and migraine with aura, the role of a PFO in exacerbating hypoxemic medical conditions (ie, sleep apnea, chronic obstructive pulmonary disease, pulmonary hypertension, platypnea-orthodeoxia, pulmonary arteriovenous malformation, high-altitude pulmonary edema, and exercise desaturation) remains less understood. PFO-mediated hypoxemia occurs when deoxygenated venous blood from the right atrium enters and mixes with oxygenated arterial blood in the left atrium. Patients with an intracardiac right-to-left shunt may have profound hypoxemia out of proportion to underlying primary lung disease, even in the presence of normal right-sided pressures. The presence of right-to-left cardiac shunting can exacerbate the degree of hypoxemia in patients with underlying pulmonary disorders. In a subset of these patients, percutaneous PFO closure may result in marked improvement in dyspnea and hypoxemia. This review discusses the association between PFO-mediated right-to-left shunting with medical conditions associated with hypoxemia and explores the role of percutaneous PFO closure in alleviating the hypoxemia.

Percutaneous Intervention to Treat Platypnea-Orthodeoxia Syndrome: The Toronto Experience

OBJECTIVES

This study reviewed a series of patients treated with transcatheter closure of septal defect to treat platypnea-orthodeoxia syndrome, with specific attention to septal characteristics and device choice.

BACKGROUND

Platypnea-orthodeoxia syndrome is an uncommon condition characterized by positional dyspnea and hypoxemia due to intracardiac right-to-left shunting through a patent foramen ovale (PFO), an atrial septal defect, or pulmonary arteriovenous malformations. Percutaneous closure of such defects is the treatment of choice.

METHODS

In this single-center series, 52 patients were treated with percutaneous closure of an interatrial communication after presentation between January 1997 and July 2015. Septal morphology, clinical, procedural, and outcomes data were analyzed.

RESULTS

All patients had a PFO; however, nearly one-quarter required a non-PFO device (11 Amplatzer Septal Occluder and 1 post-infarct muscular VSD), as opposed to a dedicated PFO device to achieve shunt occlusion. These patients were characterized by an aneurysmal septum, shorter primum septum overlap with the secundum septum, and greater septal angulation from the midline. After closure, all demonstrated acute improvements in oxygen saturation (pre-procedure: 81 ± 8%; post-procedure: 95.1 ± 0.5% on room air). Each patient was treated with a single device and no one required re-intervention.

CONCLUSIONS

Patients presenting with platypnea-orthodeoxia syndrome can be treated successfully with a percutaneous intervention often requiring a variety of devices. Those requiring a non-PFO-type device had a greater prevalence of an aneurysmal septum, shorter primum septal overlap with the secundum septum, and greater septal angulation with the midline.

Patent Foramen Ovale Closure for Hypoxemia

A patent foramen ovale (PFO) is a common anatomic finding in 20% of the normal population. Significant hypoxemia can occur in circumstances in which hemodynamic or anatomic changes predispose to increased right-to-left intra-atrial shunting. The subsequent hypoxemia produces substantial dyspnea that may affect the patient's quality of life, independent of underlying pulmonary disease. Profound hypoxemia caused by right-to-left shunt across the interatrial septum usually responds to percutaneous PFO closure. An important impediment to successful treatment is the lack of awareness of the potential role of a PFO in this condition.

Platypnea-Orthodeoxia in Patients on Hemodialysis: A New Approach to Its Pathophysiology and Implications for Treatment

Platypnea-orthodeoxia is a poorly understood clinical syndrome resulting in dyspnea and hypoxemia in the upright position, which diminishes with recumbency. Recognition of the disease is limited by its low prevalence and decreased awareness among clinicians. However, understanding the disease, its pathophysiology, its clinical presentation, and the possible therapeutic options is vital in the management of these patients. Here, we present 2 cases of platypnea- orthodeoxia where oxygen saturations worsened with hemodialysis. After highlighting the common features in the clinical pattern of each patient, we present a pressure-mediated pathophysiologic mechanism (in contrast to a previously reported morphologically based hypothesis) to explain the characteristic effects of hemodialysis on hypoxia in platypnea-orthodeoxia. We present a novel diagnostic approach using balloon occlusion testing when the diagnosis is unclear and illustrate how treatments can be tailored to the comorbidities of a specific patient.

Unusual cause of hypoxemia after automatic implantable cardioverter-defibrillatorleads extraction

The indication of pacemaker/AICD removal are numerous. Serious complication can occur during their removal, severe tricuspid regurgitation is one of the complication. The occurrence of PFO is not uncommon among adult population. Shunting across PFO in most circumstance is negligible, but in some necessitates closure due to hypoxemia. We report a case of 62 year old man, while undergoing AICD removal, had an emergency sternotomy for cardiac tamponade. Postoperatively, he experienced profound hypoxemia refractory to oxygen therapy. Transthoracic Echocardiogram was performed to rule out intracardiac shunts at an early stage, but it was difficult to obtain an good imaging windows poststernotomy. A small pulmonary emboli was noted on CTPA, but was not sufficient to account for the level of hypoxemia and did not resolve with anticoagulation. Transesophageal echocardiogram showed flail septal tricuspid valve with severe TR and bidirectional shunt through large PFO. Patient was posted for surgery, tricuspid valve was replaced and PFO surgically closed. Subsequently, patient recovered well ad was discharged to home. Cause of hypoxemia might be due to respiratory or cardiac dysfunction. But for hypoxemia refractory to oxygen therapy, transoesophageal echocardiogram should be always considered and performed early as an diagnostic tool in post cardiac surgical patients.

Persistent hypoxemia and platypnea-orthodeoxia after left single-lung transplantation: a case report

INTRODUCTION

Platypnea-orthodeoxia is a relatively uncommon but striking clinical syndrome characterized by dyspnea and deoxygenation accompanying a change to sitting or standing from a recumbent position. Hypoxemia early after lung transplant can have multiple etiologies. We report a rare case of persistent hypoxemia and platypnea-orthodeoxia after left single-lung transplantation, as a result of right-to-left interatrial shunt through a patent foramen ovale, with subsequent resolution of hypoxemia after percutaneous closure of the patent foramen ovale.

CASE PRESENTATION

Our 66-year-old Caucasian male patient exhibited a persistent patent foramen ovale. Persistent patent foramen ovale produces an intermittent intra-atrial right-to-left shunt and occurs in approximately 25 % of the general population. Although the majority of people with patent foramen ovale are asymptomatic, it is believed to act as a pathway for chemicals or thrombi that can result in a variety of clinical manifestations, including stroke, migraine headache, decompression sickness, high-altitude pulmonary edema, and platypnea-orthodeoxia syndrome. Percutaneous closure of the patent foramen ovale has been shown to be effective in the case of right-to-left shunting with normal pulmonary arterial pressure, but the indication remains controversial in other situations where pulmonary pressures are not normal. The most common causes of hypoxemia immediately after lung transplant include: graft dysfunction, reperfusion injury, acute thromboembolic disease, and acute rejection. We report a case of reopening of a patent foramen ovale after left single-lung transplantation with normal pulmonary pressure.

CONCLUSIONS

Our case demonstrates that an open patent foramen ovale leading to massive right-to-left shunting is a possible complication after lung transplant, with significant morbidity, and that it can be treated successfully using a percutaneously placed occlusion device. Through this case report, we aim to improve pre-transplant procedures by demonstrating that a bubble contrast transesophageal echocardiogram can be performed pre-operatively to detect a patent foramen ovale.

Atrial septal defect with normal pulmonary arterial pressure in adult cyanotic patient

A 22-year-old male presented with recurrent stroke, central cyanosis, and dyspnea. Transesophageal echocardiography and cardiac catheterization revealed bidirectional shunt flow through atrial septal defect (ASD) without pulmonary arterial hypertension. The orifice of inferior vena cava facing towards ASD opening led partially right to left shunt resulting in cyanosis with normal pulmonary arterial pressure.

Cardiac platypnea-orthodeoxia syndrome: an often unrecognized malady

Platypnea-orthodeoxia syndrome (POS) is a rare but clinically important form of dyspnea. The syndrome is characterized by dyspnea and arterial oxygen desaturation that occurs in the upright position and improves with recumbency. In cardiac POS, an atrial septal defect or patent foramen ovale allows communication between the right- and left-sided circulations. A second defect, such as a dilated aorta, prominent eustachian valve, or pneumonectomy, then contributes to right-to-left shunting through the interatrial connection. Diagnosis is made through pulse oximetry to confirm orthodeoxia and through transesophageal echocardiography with bubble study to visualize the shunt. Although data are limited for this rare syndrome, percutaneous closure has thus far proven safe and effective.

The brain's heart - therapeutic opportunities for patent foramen ovale (PFO) and neurovascular disease

Patent foramen ovale (PFO), a common congenital cardiac abnormality, is a connection between the right and left atria in the heart. As a "back door to the brain", PFO can serve as a conduit for paradoxical embolism, allowing venous thrombi to enter the arterial circulation, avoiding filtration by the lungs, and causing ischemic stroke. PFO-related strokes affect more than 150,000 people per year in the US, and PFO is present in up to 60% of migraine patients with aura, and in one out of four normal individuals. So, in such a highly prevalent condition, what are the best treatment and prevention strategies? Emerging studies show PFO-related neurovascular disease to be a multi-organ condition with varying individual risk factors that may require individualized therapeutic approaches - opening the field for new pharmacologic and therapeutic targets. The anatomy of PFO suggests that, in addition to thrombi, it can also allow harmful circulatory factors to travel directly from the venous to the arterial circulation, a concept important in finding novel therapeutic targets for PFO-related neurovascular injury. Here, we: 1) review emerging data on PFO-related injuries and clinical trials; 2) discuss potential mechanisms of PFO-related neurovascular disease in the context of multi-organ interaction and heart-brain signaling; and 3) discuss novel therapeutic targets and research frontiers. Clinical studies and molecular mapping of the circulatory landscape of this multi-organ disease will both be necessary in order to better individualize clinical treatment for a condition affecting more than a quarter of the world's population.

Correction of a postpneumonectomy intracardiac shunt using a tissue expander

Right-to-left interatrial shunt (RLIAS) resulting in platypnea orthodeoxia after a right pneumonectomy is an infrequent postoperative complication. Percutaneous device closure or surgical closures using cardiopulmonary bypass have been the standard interventions for RLIAS correction. We describe a technique using a tissue expander to correct a RLIAS.

A case of platypnea orthodeoxia syndrome: a persistent history taking was the key to the diagnosis

A 79-year-old woman who had been suffering from dyspnea on effort for more than 50 years was admitted for further examination and treatment. On the screening respiratory examinations, the A-aDO<inf>2</inf> was elevated but none of diffusion disturbance, ventilation-perfusion ratio inequality nor right-to-left shunt was detected. Finally, the fact that the dizziness occurred only in sitting or standing position was revealed by persistent history taking. Transesophageal echocardiography in recumbent and sitting positions revealed the platypnea orthodeoxia syndrome associated with atrial septal defect. This case highlights the necessity of awareness of this syndrome and the occult atrial septal defect.

Platypnea-Orthodeoxia Syndrome in Two Previously Healthy Adults: A Case-based Review

We describe here the clinical manifestations of platypnea-orthodeoxia in two patients with interatrial shunting. In both cases, the patients were asymptomatic prior to developing additional cardiopulmonary issues that apparently enhanced right-to-left intracardiac shunting. The patients were both treated with percutaneously deployed occlusion devices, with excellent results. Symptoms and positional oxygen desaturation resolved after device placement in both cases. In addition, these patients remain symptom-free 30 months after device implantation.

Platypnea-Orthodeoxia Syndrome After Pneumonectomy Relieved by Mediastinal Repositioning

Platypnea-orthodeoxia is a rare syndrome characterized by hypoxemia in the upright position after pneumonectomy and relieved by recumbency. This syndrome is often a post-pneumonectomy complication due to intracardiac shunt, usually at the atrial level. We report a case after right pneumonectomy without interatrial shunt. The patient was successfully treated with a silicone prosthesis implant in the post-pneumonectomy space. We believe that correction of this clinical situation has not been previously described.

Patent foramen ovale: a new disease?

Patent foramen ovale is a frequent remnant of the fetal circulation. Affecting approximately 25% of the adult population. Its recognition, evaluation and treatment has attracted increasing interest as the importance and frequency of its implication in several pathologic processes, including ischemic stroke secondary to paradoxic embolism, the platypnea-orthodeoxia syndrome, decompression sickness (DCS) (an occupational hazard for underwater divers and high altitude aviators and astronauts) and migraine headache, has become better understood. Echocardiographic techniques have emerged as the principle means for diagnosis and assessment of PFO, in particular contrast echocardiography and transcranial Doppler. Its treatment remains controversial with a general tendency to propose a percutaneous closure among the symptomatic patients.

Tricuspid Regurgitation Causing a Right to Left Interatrial Shunt with Normal Pulmonary Pressures

We describe a patient who presented with asymptomatic hypoxia refractory to supplemental oxygen. Transthoracic echocardiography and angiography demonstrated a tricuspid valve with a large regurgitant jet oriented directly at a patent foramen ovale, producing a right to left shunt with systemic hypoxia. The patient was found to have normal right-sided cardiac pressures as well as normal pulmonary arterial pressures, demonstrating the shunt was secondary to the tricuspid regurgitant jet and not a result of a pressure gradient between atria. Surgical correction of the tricuspid valve and closure of the patent foramen ovale resulted in resolution of the patient's hypoxemia.

Transcatheter Device Closure of Interatrial Septal Defects in Patients with Hypoxia

BACKGROUND

There has been growing interest in transcatheter closure of interatrial septal defects (IASDs) for a variety of indications, but reports are limited in patients with hypoxia from right-to-left shunting.

METHODS

Between August 2000 and October 2004, 181 patients were referred to our institution for elective closure of a patent foramen ovale (PFO) or atrial septal defect (ASD). Among these patients, 10 (5.5%) underwent closure for hypoxia due to persistent or intermittent right-to-left shunting. Clinical evaluation, including echocardiography with color Doppler and agitated saline, was performed in all patients to determine the degree of right-to-left shunting. Defects were closed with Amplatzer (n = 4) or Cardioseal (n = 6) devices, under transesophageal (TEE) or intracardiac echocardiography (ICE) guidance.

RESULTS

Mean age was 62.7 years (range: 31-88 years) with 70% female. Characteristics for closure included four patients with persistent hypoxia and six with intermittent hypoxia, including two with platypnea-orthodeoxia syndrome. All patients had echocardiography showing moderate (n = 6) or severe (n = 4) shunting. Patients had significant comorbidities, including chronic lung disease requiring supplemental oxygen (n = 5) and congestive heart failure (n = 2). TEE guidance was used in three patients, and ICE was performed in the remainder. Mean closure device diameter was 27 mm. Mean preprocedural arterial oxygen saturation of 86.7% improved to 95.9% immediately after closure, with color Doppler and agitated saline revealing the absence of (n = 5) or mild (n = 5) shunting. In-hospital major complications were limited to one patient with a transient ischemic attack after an initially unsuccessful closure attempt.

CONCLUSIONS

Percutaneous closure of IASDs in a heterogeneous group of patients with hypoxia can be safely and effectively performed. The procedure results in immediate arterial saturation improvement and reduced right-to-left shunting.

Transcatheter Closure of Patent Foramen Ovale in Patients with Platypnea-Orthodeoxia: Results of a Multicentric French Registry

BACKGROUND

Dyspnea and the decrease in arterial saturation in the upright position in elderly subjects is described as platypnea-orthodeoxia syndrome (POS). POS is secondary to the occurrence of an atrial right-to-left shunt through a patent foramen ovale (PFO).

METHODS

This French multicentric study reports on 78 patients (mean age 67 +/- 11.3 years) with POS who had transcatheter closure of the PFO; frequently associated diseases were pneumonectomy (n = 36) and an ascending aortic aneurysm (n = 11). In all patients, the diagnosis was confirmed by transthoracic or/and transesophageal echocardiography. Five different closure devices were used: Amplatz (n = 45), Cardioseal (n = 13), Sideris (n = 11), Das Angel Wings (n = 8) and Starflex (n = 1). Closure was successful in 76 patients (97%).

RESULTS

Oxygen saturation increased immediately after occlusion from 84.6 +/- 10.7% to 95.1 +/- 6.4% (p < 0.001) and dyspnea improved from grade 2.7 +/- 0.7 to grade 1 +/- 1 (p < 0.001). A small residual shunt was immediately observed in 5 patients (3 with the Cardioseal device, 1 with the Sideris and 1 with the Amplatz) leading to the implantation of a second device in one case (Cardioseal). Two early deaths occurred unrelated to the procedure (one due to sepsis probably related to pneumonectomy, another due to respiratory insufficiency). Other complications were: a small shunt between the aorta and the left atrium, two atrial fibrillations and a left-sided thrombus which disappeared with anticoagulant therapy. At a mean follow-up of 15 +/- 12 months, there were 7 late deaths related to the underlying disease.

CONCLUSION

Percutaneous occlusion of the foramen ovale is safe and gives excellent results thanks to continuing improvement in available devices. This technique enables some patients in an unstable condition to avoid a surgical closure.

Interatrial Right-to-Left Shunt after Lung Surgery: Diagnostic Value of Perfusion Lung Scanning

A 61-year-old woman presented with platypnea and orthodeoxia after right pneumonectomy for lung cancer. A perfusion lung scan taken after tracer injection in the sitting position showed an extrapulmonary uptake of radioactivity consistent with a right-to-left shunt. Such extrapulmonary uptake was no longer evident when tracer was injected in supine posture. The authors emphasize the value of perfusion lung scanning in the assessment of patients with unexplained dyspnea after thoracic surgery.

Platypnea-orthodeoxia: Report of Two Cases and Review of the Literature

We describe two unusual cases of platypnea. The first patient had chronic obstructive pulmonary disease, but platypnea did not respond to chronic obstructive pulmonary disease therapy. He was found to have multiple pulmonary emboli, and symptoms rapidly improved on anticoagulation therapy. The second patient had Parkinson disease and developed severe platypnea, an association that has not been previously described. She had significant postural hypotension and responded to therapy with fludrocortisone.

Clinical impact of patent foramen ovale diagnosis with transcranial Doppler

The role of patent foramen ovale (PFO) in cryptogenic stroke is still debated, but from recent follow-up studies it seems that the amount of right-to-left shunt (RLS) and the association with atrial septal aneurysm (ASA) are major determinants of stroke recurrence. PFO and RLS through the atrial chambers have been recently studied in a number of conditions not or marginally related to cerebrovascular disease. Historically the first studies addressed the presence of RLS in scuba divers as a possible abnormality related to decompression sickness (DS) of unknown aetiology. Despite initial debate there is now robust evidence to claim that patency of foramen ovale increases the risk of developing DS by two and half to four times. Patients with PFO-related DS tend to have early occurrence of symptoms after surfacing and a clinical presentation that indicates brain or upper cervical spinal cord involvement. Recent reports suggest that divers with hemodynamically significant RLS may have an increased risk of developing clinically asymptomatic multiple brain lesions. PFO has been found in patients suffering from migraine with aura with approximately the same frequency as that encountered in cryptogenic stroke patients. This finding has prompted speculations on the possible role of RLS in increasing the stroke risk in migraineurs and in the pathophysiology of the aura. Recent reports showing that migraine with aura is dramatically improved after transcatheter closure of PFO suggest that migraine with aura may indeed be triggered by humoral factors that reach the brain by escaping the pulmonary filter. A RLS is involved in a rare condition known as platypnea-orthodeoxia and perhaps underlies an increased risk of cerebral complications after major orthopedic surgery. Valsalva-like activities often precede the occurrence of attacks of transient global amnesia (TGA) and abnormalities consistent with hypoperfusion of deep limbic structures have been reported during a typical TGA episode. This had raised the hypothesis that TGA may be triggered by paradoxical embolism of platelets aggregates in the posterior circulation, but the search for an increased frequency of PFO in TGA patients has yielded conflicting results. Conditions that determine an increase in pulmonary pressure may facilitate the opening of the virtual interatrial valve and thus promoting shunting of blood to the left heart chambers which in turn might contribute to further desaturation of arterial blood. It is therefore not surprising that RLS has been found in 70% of patients with chronic obstructive pulmonary disease and increased pulmonary pressure and in the same proportion of patients with obstructive sleep apnoea, a condition that ultimately may result in pulmonary hypertension. In conclusion, from the evidence gathered so far the picture is emerging of an important role of PFO in a number of non-stroke conditions, either as causative factor or as associated condition predisposing to complications. The availability of simple diagnostic techniques such as transcranial Doppler (TCD) to assess RLS will undoubtedly contribute a great deal of knowledge on the relevance in medicine of this hitherto neglected condition.

Platypnea-orthodeoxia: management by transcatheter buttoned device implantation

Dyspnea and arterial desaturation on upright position in elderly subjects is described as platypnea-orthodeoxia syndrome (POS) and in some patients it is due to right-to-left shunt across the atrial septal defect (ASD)/patent foramen ovale (PFO). Surgical closure of ASD/PFO has been the only available treatment option. Buttoned device has been used for occlusion of ostium secundum ASD, PFO associated with presumed paradoxical embolism and cerebrovascular accidents and ASD/PFO in association with other congenital heart defects causing right-to-left shunt. The objective of this article is to describe the use of buttoned device in effectively occluding ASD/PFO to relieve hypoxemia of POS. During a 4-year period ending January 2000, 10 patients, ages 71 +/- 9 (range 60-83) years with POS underwent buttoned device closure of their ASD/PFO. Echocardiographic and balloon-stretched atrial defect sizes were 8 +/- 3 mm and 12 +/- 3 mm, respectively. The ASD/PFO were occluded with devices ranging in size from 25 to 40 mm delivered via 9 French, long, blue Cook sheaths; eight had an additional 25- or 35-mm occluder placed on the right atrial side. The oxygen saturation increased (P < 0.001) from 76 +/- 7% (range 69-86%) to 95 +/- 2% (range 92-98%). No complications were encountered. Relief of symptoms was seen in all patients. Follow-up of 1-36 months (median 12 months) revealed persistent improvement of symptoms. Buttoned device occlusion of ASD/PFO to relieve hypoxemia of POS is feasible, safe, and effective and is an excellent alternative to surgery. Cathet Cardiovasc Intervent 2001;54:77-82.

Patent foramen ovale: a review of associated conditions and the impact of physiological size

Patent foramen ovale (PFO) is implicated in platypnea-orthodeoxia, stroke and decompression sickness (DCS) in divers and astronauts. However, PFO size in relation to clinical illness is largely unknown since few studies evaluate PFO, either functionally or anatomically. The autopsy incidence of PFO is approximately 27% and 6% for a large defect (0.6 cm to 1.0 cm). A PFO is often associated with atrial septal aneurysm and Chiari network, although these anatomic variations are uncommon. Methodologies for diagnosis and anatomic and functional sizing of a PFO include transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) and transcranial Doppler (TCD), with saline contrast. Saline injection via the right femoral vein appears to have a higher diagnostic yield for PFO than via the right antecubital vein. Saline contrast with TTE using native tissue harmonics or transmitral pulsed wave Doppler have quantitated PFO functional size, while TEE is presently the reference standard. The platypnea-orthodeoxia syndrome is associated with a large resting PFO shunt. Transthoracic echocardiography, TEE and TCD have been used in an attempt to quantitate PFO in patients with cryptogenic stroke. The larger PFOs (approximately > or =4 mm size) or those with significant resting shunts appear to be clinically significant. Approximately two-thirds of divers with unexplained DCS have a PFO that may be responsible and may be related to PFO size. Limited data are available on the incidence of PFO in high altitude aviators with DCS, but there appears to be a relationship. A large decompression stress is associated with extra vehicular activity (EVA) from spacecraft. After four cases of serious DCS in EVA simulations, a resting PFO was detected by contrast TTE in three cases. Patent foramen ovales vary in both anatomical and functional size, and the clinical impact of a particular PFO in various situations (platypnea-orthodeoxia, thromboembolism, DCS in underwater divers, DCS in high-altitude aviators and astronauts) may be different.