Interatrial right-to-left shunting developing after pulmonary resection in the absence of elevated right-sided heart pressures. Review of the literature

Case report: Unusual cause of refractory hypoxemia after pacemaker lead extraction

A 59-year-old woman with a history of a pacemaker implanted for III-degree atrioventricular block was admitted due to pocket infection. The atrial and ventricular leads were removed via the right femoral vein using a needle's eye snare. Hypoxemia was observed immediately after the removal of the lead. It was refractory to oxygen therapy. The pulse oxygen saturation (SpO2) showed 89% in the supine position and 77% in the upright position. However, the CTPA and pulmonary perfusion SPECT/CT imaging did not reveal any signs of pulmonary embolism. Pulmonary function tests and chest CT showed normal results. Transthoracic contrast echocardiography revealed a patent foramen ovale (PFO) and a right-to-left intracardiac shunt, no significant tricuspid regurgitation, without any signs of elevated right heart pressure or pulmonary hypertension. Hypoxemia was considered to be associated with the right-to-left shunt through PFO. The condition was relieved by percutaneous closure of the PFO. Refractory hypoxemia resulting from an intracardiac right-to-left shunt following pacemaker lead extraction is a rare but serious complication. Transthoracic contrast echocardiography helps in diagnosis. If the right-to-left intracardiac shunt through PFO persists irreversibly and the associated hypoxemic symptoms are significant, closure of the PFO is necessary. Transesophageal echocardiography also revealed the presence of a left-to-right shunt through PFO during cardiac systole. The closure of the PFO is also necessary to avoid long-term complications, such as chronic pulmonary hypertension and right heart failure.

Orientation of the atrial septum to the inferior vena cava may contribute to the persistent patency of the foramen ovale

Purpose: There is growing evidence that paradoxical embolism through patent foramen ovale (PFO) is a cause for cryptogenic stroke. However, it is still unclear why the foramen ovale fails to close after birth. We studied whether the 3D relations between the atrial septum and the inferior vena cava (IVC) are associated with PFO. Methods: We recruited 30 patients (18-49 years) with a first-ever cryptogenic stroke and 30 age- and sex-matched stroke-free controls. Using cardiac magnetic resonance (CMR), an approach to evaluate the 3D relations between the atrial septum and the IVC was developed. The presence of interatrial right-to-left shunt was evaluated with transesophageal echocardiography (TEE) in patients and transcranial Doppler in controls. Results: Of 30 patients, 29 underwent successful TEE, of which 12 (41%) had a shunt. Patients with a shunt had a greater mean 3D angle (γ) between the atrial septal plane and the vector from the orifice of the IVC to the middle of the atrial septum compared with patients without a shunt (45±9° vs. 36±8°, p=0.017). Of 30 controls, 12 (40%) had a shunt and a greater mean γ compared with controls without a shunt (47±8° vs. 37±10°, p=0.007). In a pooled analysis, 24 (41%) of 59 subjects with a shunt had a mean γ of 46±9° compared with subjects without a shunt of 37±9° (p<0.001). Conclusions: More perpendicular orientation of the atrial septal plane to the orifice of the IVC is associated with PFO, possibly by directing the IVC flow to PFO.

Platypnoea-orthodeoxia syndrome due to a right-to-left interatrial shunt following pneumonectomy

A 62-year-old man presents with breathlessness 6 months following right pneumonectomy for lung adenocarcinoma. Previous investigations had not yielded a diagnosis and his symptoms were progressing. The patient described worsened symptoms when stood up (platypnoea), with profound hypoxia until laid supine (orthodeoxia). Platypnoea-orthodeoxia syndrome due to a right-to-left interatrial shunt was diagnosed on contrast-enhanced transoesophageal echocardiography with the patient undergoing successful percutaneous patent foramen ovale closure. Patent foramen ovale is often asymptomatic with a population prevalence of around 20%-30%. Anatomical shifts postpneumonectomy can open, or worsen a previously closed interatrial communication leading to right-to-left shunting of blood. Platypnoea-orthodeoxia is under-recognised, impairing quality of life and patient outcome. Investigations can be falsely reassuring, or poorly sensitive for the causative pathology. Percutaneous closure is safe with high success rates and this case highlights the need for a high index of suspicion for shunts, particularly in postpneumonectomy patients.

Posture Dependent Hypoxia Following Lobectomy: The Achilles Tendon of the Lung Surgeon?

BACKGROUND

Platypnoea-Orthodeoxia Syndrome is an uncommon phenomenon characterized by dyspnea/arterial desaturation in the standing position, resolving in recumbency. Some patients present with Platypnoea-Orthodeoxia Syndrome in the early-or-late post-operative period after major lung resection (lobectomy/pneumonectomy). The main cause of Platypnoea-Orthodeoxia Syndrome is an intracardiac anomaly (Patent Foramen Ovalis/Atrial Septal Defect) leading to right-to-left shunt.

OBJECTIVES

To identify the causes of post-lobectomy Platypnoea-Orthodeoxia Syndrome, and the possible pathophysiologic mechanism.

METHODS

A Pubmed database-EMBASE systematic review was performed in order to find all reports, reporting the occurrence of dyspnea/hypoxemia after lobectomy.

RESULTS

8 studies were found concerning ten patients during the period from 1983-2019.There was 6 male/4 female. The mean age was 62 years. All patients underwent resection of the right lung. The time-interval between the operation and the Platypnoea-Orthodeoxia Syndrome was from 2 days to 3 years. A Patent Foramen Ovalis was present in 90% and in 10% an Atrial Septal Defect was diagnosed. The mean Right Atrial Pressure was 7.5 mmHg, the mean Left Atrial Pressure was 6.6 mmHg and the mean Pulmonary artery pressure was 18.5 mmHg. The mean size of the interatrial communication was 1.62 cm. The inter-atrial communication was closed by open-chest surgical procedure in 3 cases (30%) and in 7 patients (70%) a percutaneous transcatheter device was implanted.

CONCLUSIONS

Platypnoea-Orthodeoxia Syndrome after lobectomy is a rare cause of post-operative dyspnea/hypoxia. It is the result of right-to-left shunt via an interatrial communication. Mediastinal relocation, stretching of the atrial septum and aortic root dilatation are among the functional elements necessary for the Platypnoea-Orthodeoxia Syndrome manifestation.

A rare post-lobectomy complication of right-to-left shunt via foramen ovale

BACKGROUND

Various complications can cause hypoxemia after pulmonary resection for lung cancer, but intracardiac shunt that becomes symptomatic and causes severe hypoxemia postoperatively is very rare. We report a case that presented platypnea-orthodeoxia syndrome (POS) due to right-to-left shunt via patent foramen ovale (PFO).

CASE

A 71-year-old man with a lung cancer in the left upper lobe was referred to our hospital. Left upper lobectomy was performed. Dyspnea developed postoperatively, which was worsened by sitting or standing and relieved in a recumbent position. Contrast transesophageal echocardiogram (TEE) and right intracardiac catheterization revealed a right-to-left shunt via PFO. Open-heart closure of PFO was performed and the patient was free from POS.

CONCLUSIONS

Postoperative intracardiac shunt via PFO can cause severe hypoxemia after lung resection. POS suggests the possibility of intracardiac shunt and careful observation is needed.

Dyspnea following thoracostomy closure after right pneumonectomy: An uncommon echocardiographic diagnosis and therapeutic approach

Dyspnea and hypoxemia are common postoperative problems after pneumonectomy. One of the rarer causes of respiratory distress after right pneumonectomy is the development of a significant right-to-left shunt across a patent foramen ovale (PFO), which can evolve at a variable interval of time after the operation. We report here our experience with a patient who underwent right pneumonectomy, followed by several complications, and who presented severe dyspnea 7 months later, after the closure of a right thoracostomy. This report outlines the management of this challenging clinical condition; transesophageal echocardiography (TOE) provided a clear diagnosis and guided an effective percutaneous treatment.

Postpneumonectomy Compression of the Mitral Annulus: Rare Vascular Complication in Sportive Patient

Numerous postpneumonectomy complications exist. We present a rare clinical case of postpneumonectomy exertional dyspnea revealing compression of the mitral annulus by the descending aorta. The patient was 42-year-old former smoker with pulmonary emphysema. He has been operated on, in 2012 (i.e., right pneumonectomy). Before the surgery, the patient was a recreational runner. However, after some months, it was difficult for the patient to resume running. Cardiopulmonary exercise testing indicated moderate exercise intolerance with important oxygen desaturation. More interestingly, a decrease of low oxygen pulse was noticed from the first ventilatory threshold with no electrical modification on the electrocardiogram. This decrease was indicative of a decline in stroke volume. The thoracic scan revealed a right pneumonectomy pocket with a liquid abnormal content. Moreover, the mediastinum had shifted toward the pneumonectomy space and the left lung was distended and emphysematous. Echocardiography revealed a major change in the mediastinal anatomy. The mitral annulus was observed to be compressed by the rear wall of the descending aorta. The diagnosis of postpneumonectomy syndrome or platypnea-orthodeoxia syndrome was ruled out in this patient. Mitral annular compression by the descending aorta is rare complication, which must be researched in patients with postpneumonectomy exertional dyspnea.

Platypnea-orthodeoxia syndrome in patients presenting enlarged aortic root: case report and literature review

We describe herein a case of a patient who, when in orthostatic positions, had severe hypoxemia and ventilatory dysfunction. Although the severity of symptoms required hospitalization in an intensive care setting, the initial tests only identified the presence of enlarged aortic root, which did not explain the condition. The association of these events with an unusual etiology, namely intracardiac shunt, characterized the diagnosis of platypnea-orthodeoxia syndrome. The literature review shows that, with advancing research methods, there was a progressive increase in the identification of this condition, and this association should be part of the differential diagnosis of dyspnea in patients with enlarged aortic root.

Platypnoea-orthodeoxia syndrome, an underdiagnosed cause of hypoxaemia: four cases and the possible underlying mechanisms

Cardiac platypnoea-orthodeoxia syndrome (POS) is a position-dependent condition of dyspnoea and hypoxaemia due to right-to-left shunting. It often remains unrecognised in clinical practice, possibly because of its complex underlying pathophysiology. We present four consecutive patients with POS and patent foramen ovale (PFO) who underwent a successful percutaneous PFO closure, describe the mechanism of their POS and provide a review of the literature.

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.

Right-to-left atrial shunting associated with aortic root aneurysm: a case report of a rare cause of platypnea-orthodeoxia syndrome

Platypnea-orthodeoxia is a rare syndrome characterised by dyspnoea and hypoxaemia worsened on upright posture. We report the case of a 76 year-old man treated for lung adenocarcinoma who had developed severe hypoxaemia due to right-to-left shunt through a patent foramen ovale (PFO). Diagnosis was suspected by systemic uptake of isotope during lung scintigraphy performed to exclude pulmonary embolism. Arterial blood gas analysis in supine and upright positions demonstrated orthodeoxia. Contrast-enhanced transoesophageal echocardiography revealed a slightly redundant atrial septum and large right-to-left shunt through a PFO despite normal pulmonary pressure. Chest computed tomography and echocardiography showed a 59-mm aneurysm of the thoracic aorta. The opening of the PFO seemed to be the result of mechanical deformation of the atrial septum by aortic root dilatation. Transcatheter closure of the atrial defect has provided excellent results, including a rapid increase in systemic saturation and improvement of symptoms without any complications.

Patent foramen ovale: Its significance in anesthesia and intensive care: An illustrated case

Patent foramen ovale (PFO) is defined as a valve-like opening at the level of foramen ovale or between septum primum and secundum without evidence of the anatomical defect. Paradoxical embolism (PDE) is an embolus passing through a defect PFO leading to end-organ dysfunction. PDE in septic shock is not yet reported in the literature. A 49-year male presented to the emergency department with shortness of breath since one day and pain in the left side of the chest. Chest x0 -ray revealed middle-left lobe pneumonia with pleural effusion; he was started on Co-amoxiclav, and admitted to the ward. After 6 h, his chest pain suddenly significantly increased difficulty in breathing and his oxygen saturation dropped. X-ray of the chest showed left pneumothorax, chest drain was inserted and he was intubated. He became hemodynamically unstable with maximum ventilatory support and noradrenalin. On day 4, he was found to have new pansystolic murmur in the tricuspid area. An echocardiogram revealed global hypokinesia, two mobile thrombi in the right atrial cavity, and PFO. It was noticed that his right toe had blackish discoloration. An angiogram showed occlusion of the right superficial femoral artery and immediately an embolectomy. On day 11, he was transferred to the ward. PDE needs a high index of suspicion in septic shock patients with ARDS. PDE requires PEEP adjustment, early anticoagulation, and thromboprophylaxis.

Platypnea-orthodeoxia due to osteoporosis and severe kyphosis: a rare cause for dyspnea and hypoxemia

Platypnea orthodeoxia is a rare disorder characterized by dyspnea and arterial desaturation, exacerbated by the upright position and relieved when the subject is recumbent. We report the case of a 79-year old woman admitted to hospital with dyspnea who was thought to have restrictive ventilatory impairment due to osteoporosis and severe kyphosis. Interestingly, the dyspnea was aggravated in the upright position, whereas the symptoms improved in the supine position. Arterial blood gas analysis confirmed orthodeoxia. The lung function test showed only a mild obstructive and restrictive ventilation disorder. Echocardiography revealed a patent foramen ovale and an aneurysm of the atrial septum protruding into the left atrium, despite normal right atrial pressure. Transesophageal echocardiography showed a prominent Eustachian valve guiding a blood flow from the inferior vena cava directly onto the atrial septum, thereby pushing open the patent foramen ovale. Contrast-enhanced echocardiography confirmed a spontaneous right-to-left shunt through the patent foramen ovale. It was assumed that the platypnea-orthodeoxia was caused by a prominent Eustachian valve redirected to the patent foramen ovale as a result of severe osteoporosis with subsequent thoracic kyphosis and a change in the position of the entire heart. The patient underwent permanent transcatheter closure of the patent foramen ovale after hemodynamic assessment had confirmed a significant right-to-left shunt through it. After the procedure the arterial oxygen pressure increased significantly in the upright position and dyspnea improved.

[Hypoxemia 4 month after right-sided pneumonectomy]

A 64-year-old male reported worsening dyspnea four months after right-sided pneumonectomy, due to lung cancer. Platypneu-or-thodeoxie syndrome was suspected due to a decrease in oxygen-saturation while the patient was in upright position. The shift of the right hemidiaphragm and liver caused compression of the right atrium and a shunt over a persistent foramen ovale. The right-to-left shunt was proven during right heart catheter. Interventional closure of the shunt resulted in immediate improvement of arterial oxygenation and a decrease in dyspnea.

What the cardiologist should know about the management of platypnea-orthodeoxia syndrome

Platypnea-orthodeoxia syndrome is a rare and poorly understood condition related to the development of a right-to-left intracardiac shunt at the atrial level through a benign and silent patent foramen ovale. It is usually recognized after major lung resection, recurrent pulmonary embolism or chronic lung disease. Orthostatic dyspnea and cyanosis is the prominent clinical presentation. Symptoms increase in the upright position and are relieved by recumbency. Our report describes the clinical course of a patient with severe hypoxemia after left pneumonectomy attributable to a right-to-left shunting through an atrial septal defect.

Transient adverse events positively associated with patent foramen ovale after ultrasound-guided foam sclerotherapy

Objectives

To prospectively study the association between patent foramen ovale (PFO) detected by contrast transcranial Doppler (cTCD) and adverse events (AEs) reported by patients after ultrasound-guided foam sclerotherapy (UGFS) for the treatment of varicose veins.

Methods

All patients reporting AEs after UGFS were studied using cTCD directed at the middle cerebral artery to determine the Spencer grading score by counting high-intensity transient signals. Agitated saline was used as the contrast medium. The Spencer grading score determined the presence or absence of PFO. All patients undergoing UGFS received follow-up phone calls within 24 hours and again two weeks after the procedure.

Results

Of the 3259 patients who underwent UGFS, AEs were reported by seven (0.21%) patients at their first session. These included visual disturbance, migraine and chest discomfort. Five (71.4%) of these seven patients tested positive for PFO by cTCD. The two-week follow-up confirmed no permanent symptoms. Published studies show high sensitivity and specificity for cTCD when compared with contrast transesophageal echocardiography (cTEE).

Conclusions

The overall rate of AEs reported is consistent with published results. The presence of a PFO was detected in most patients reporting AEs after undergoing UGFS. While PFO screening with high sensitivity and specificity can be performed efficiently in the clinic setting, based on the literature, further investigation is warranted.

A broken heart: right-to-left shunt in the setting of normal cardiac pressures

A patent foramen ovale (PFO) is a common structural cardiac variant occurring in approximately 30% of the general population. Patients are usually asymptomatic because the defect is flap-like and does not permit significant left-to-right shunting. However, pathological conditions that result in cardiac rotation or higher than normal right atrial pressures can reverse the normal left atrial to right atrial pressure gradient and cause a right-to-left shunt through a PFO. If the right-to-left shunt is persistent, systemic hypoxemia or paradoxical emboli may result. The present report describes a case of refractory hypoxemia in a critically ill patient with a PFO who had a right-to-left shunt with normal right-sided cardiac pressures.

Dual mechanism platypnea-orthodeoxia syndrome from severe right coronary artery stenosis and a patent foramen ovale

Platypnea-orthodeoxia is a rare clinical syndrome characterized by hypoxemia induced during upright posture. Multiple mechanisms have been proposed to explain this clinical entity, usually involving posture-provoked intracardiac or transpulmonary shunting. In many cases, however, a single etiology may not be evident, and multiple factors are likely contributory. We herein describe an unusual and novel case of platypnea-orthodeoxia caused by the physiologic interaction between a severe proximal right coronary artery stenosis and a large patent foramen ovale. Percutaneous stenting of the right coronary artery and transcatheter closure of the patent foramen ovale during the same setting resulted in complete resolution of the patient's symptoms.

The Incidental Finding of a Patent Foramen Ovale During Cardiac Surgery: Should It Always Be Repaired? A Core Review

With the increased use of intraoperative transesophageal echocardiography, patent foramen ovale (PFO) has become a common finding during heart surgery. This finding presents a difficult dilemma for cardiac surgeons, since the impact of intraoperatively diagnosed PFOs on postoperative outcome is unknown. Changes in the surgical plan required for closure of a PFO subject the patient to the possibility of additional risk. On the other hand, a decision to not close a PFO exposes the patient to unclear immediate and long-term consequences. Deciding whether or not to close a PFO currently depends on the clinicians' personal preferences, the probability of intraoperative and postoperative hypoxemia, and any anticipated deviation from the initial surgical plan. Most clinicians agree that an intraoperatively diagnosed PFO must be closed when surgery leads to a high risk of hypoxemia (e.g., left ventricular assist devices placement, heart transplantation); should be closed in most cases when minimal deviation from the initial surgical plan is needed for PFO closure (e.g., mitral valve or tricuspid valve surgeries); and probably, should be closed during heart surgeries performed without atriotomy and bicaval cannulation when the risk of perioperative or remote PFO-related complications is increased. The recent development of percutaneous methods of PFO closure provides a valuable backup for those cases when PFO is not closed and postoperative hypoxemia or other complications may be attributable to the uncorrected PFO.

Coronary artery bypass graft and/or valvular operations following prior pneumonectomy: report of four new patients and review of the literature

BACKGROUND

The reported experience is sparse for patients with prior pneumonectomy who are undergoing surgery for ischemic or valvular heart disease. Such surgery poses special technical challenges. To expand the experience with this challenging clinical intervention, we reviewed the reported patients with prior pneumonectomy who were undergoing cardiac surgery as well as the experience at the Cleveland Clinic.

METHODS

A MEDLINE search of the literature for articles published in the English language from 1966 to August 2006 was conducted using the search terms "pneumonectomy" and "cardiac surgery." We included all available individually described patients and also reviewed the Cardiovascular Information Registry at the Cleveland Clinic from 1972 to 2006.

RESULTS

A total of 19 individually described patients in 13 reports were available, 15 of which had previously been reported and 4 that were newly reported from our institution (1 of whom had undergone two operations separated by 8 years). Of the 20 operations performed in these 19 patients, coronary artery bypass grafting (CABG) alone was performed in 15 patients (75%), valve replacement or repair was performed in 4 patients (20%), and CABG with both aortic valve replacement and mitral valve repair was performed in 1 patient (5%). Most patients (13; 68%) had undergone left pneumonectomy. For these 19 patients, the postoperative mortality rate was 16%. Postoperative complications followed 10 of the operations (50%).

CONCLUSIONS

Although complications and postoperative deaths occurred more frequently than in other high-risk patient groups (eg, those with COPD undergoing cardiac surgery), this experience suggests that cardiac surgery can be undertaken with a reasonable likelihood of a favorable outcome in this challenging population, justifying the approach in appropriately selected and counseled patients.

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.

Cardiovascular Complications After Lung Surgery

Cardiovascular complications following thoracic surgery remain a challenge to the physician, the hospital, and the health care system. These events add significantly to morbidity, mortality, and the cost of care of the general thoracic surgery patient. A proactive approach to identify patients at high risk for such complications is needed. In this manner, one may enhance prevention and treatment if problems occur. A thoughtful and complete preoperative risk assessment can identify patients who have potential contributing comorbidities, leading to a reduced incidence of postoperative events. Standardization of preoperative, intraoperative, and postoperative care can reduce postoperative events. Implementation of guidelines and pathways that are evidence based can lead to enhanced patient care, better patient and staff satisfaction, and improved outcomes from the operation. Although postoperative cardiac events cannot be completely eliminated from the thoracic surgery population, the prevention, treatment, and follow-up strategies outlined herein can attenuate these significant morbid and mortal events.

Detection of Right to Left Shunt by Transesophageal Echocardiography in a Patient with Postoperative Hypoxemia

Intracardiac right to left shunt through a patent foramen ovale (PFO) may result in the development of hypoxemia after cardiac surgery. Cardiac tamponade and mechanical ventilation with high positive endexpiratory pressure are the most common factors responsible for enhancing intracardiac right to left shunt through a PFO. We report an 83-year-old woman with Stanford type A dissecting aneurysm who developed hypoxemia and paradoxical air embolism after reconstruction of ascending aorta and Bental's procedure. Transesophageal echocardiography (TEE) revealed right to left shunting via a PFO. Surgical closure of the PFO was done without delay. This case illustrates the role of TEE in prompt diagnosis of intracardiac right to left shunting through a PFO causing postoperative hypoxemia after cardiac surgery.

A mystery featuring right-to-left shunting despite normal intracardiac pressure

The cause of right-to-left atrial shunting despite normal intracardiac pressures and normal or near-normal pulmonary function through a patent foramen ovale has still not been completely clarified. It is probably responsible for several linked diseases, such as paradoxical embolism, platypnea-orthodeoxia syndrome, migraine with aura, transient global amnesia, and decompression sickness in sport divers. Despite modern diagnostic methods, the underlying anatomophysiologic and pathogenic mechanisms of right-to-left atrial shunting without abnormal intracardiac pressures remain a matter of debate and controversy. Holistically speaking, a return to a direct study of embryology, gross anatomy, and physiology may help us elucidate the real mechanism of this paradoxical shunting.

A rare complication of pneumonectomy: Diagnosis made by a literature search

This case describes platypnoea-orthodeoxia syndrome in a patient 2 months after a right pneumonectomy for adenocarcinoma of the lung. The patient complained of platypnoea (breathlessness in the upright position) and was noted to have orthodeoxia (arterial desaturation on standing) on clinical examination. This was due to anatomical changes after the pneumonectomy that resulted in direct blood flow from the inferior vena cava through a previously unrecognised atrial septal defect into the left atrium. The closure of this right to left shunt with an Amplatzer occluder produced immediate and striking symptomatic relief in the patient. The authors had no previous experience of this very rare complication of pneumonectomy. The diagnosis was made after a literature search using PubMed/Medline, underlining the direct clinical benefit provided by these databases.

Severe hypoxemia in a patient with acute myocardial infarction

A case report of a patient with acute myocardial infarction and severe hypoxemia due to acute right to left interatrial shunt (RLIAS) is presented. Diagnostic and therapeutic procedures are discussed.

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.

Cardiac complications after noncardiac thoracic surgery: an evidence-based current review

Despite advances in perioperative management, thoracic surgery remains a high-risk procedure for many patients. A systematic review of cardiac complications after thoracic surgery is presented. Most reviews about noncardiac thoracic surgery discuss postoperative analgesic regimens and pulmonary complications. In the present review, we also discuss atrial fibrillation as the most frequently encountered cardiac side effect. An evidence-based approach to other complications, such as myocardial ischemia, pulmonary edema, embolism, and shunt, is described. Furthermore, we offer recommendations for daily practice.

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.

A case of orthodeoxia caused by an atrial septal aneurysm

Platypnea-orthodeoxia is an uncommon syndrome that may occur due to the postpneumonectomy state, cirrhosis of the liver, recurrent pulmonary embolism, and intracardiac shunting. We describe a patient who was found to have a positional change in desaturation after being admitted for dehydration. Workup revealed an atrial septal defect with aneurysm. Following surgical repair, the orthodeoxia resolved. Different mechanisms explain positional desaturation, such as atriovenous malformations at the lung base of cirrhotic patients. In an atrial septal defect, the increased shunting of blood across a malformed septum in an upright position may cause orthodeoxia. This case highlights the necessity of heightened awareness of this syndrome and the need for documenting orthostatic changes in cases of severe hypoxemia.

Effect of body position changes on pulmonary gas exchange in Eisenmenger's syndrome

Preliminary studies on sleep of patients with congenital heart disease and Eisenmenger's syndrome (ES) at our institution demonstrated nocturnal worsening arterial unsaturation, which appeared to be a body position-related phenomenon. To investigate the potential effect of body position on gas exchange in ES, we carried out a prospective study of 28 patients (mean age, 34.8 +/- 11.7 yr) with established ES due to congenital heart disease. In every patient, arterial blood gases were performed during both sitting and supine positions under three different conditions: room air, while breathing 100% oxygen, and after breathing oxygen at a flow rate of 3 L/min through nasal prongs. Alveolar oxygen pressure (PaO2) for the calculation of alveolar-arterial oxygen tension differences (AaPO2) was derived from the alveolar gas equation using PaCO2 and assuming R = 1. We used paired t test, repeated-measures two-way ANOVA with Bonferroni's test, and regression analysis. From sitting to supine position on room air, there was a significant decrease in PaO2 (from 52.5 +/- 7.5 to 47.5 +/- 5.5 mm Hg; p < 0. 001) and SaO2 (from 86.7 +/- 4.6 to 83.3 +/- 4.9%; p < 0.001), both of which were corrected by nasal O2 (to 68.2 +/- 21 mm Hg and to 92 +/- 4%, respectively, p < 0.005). PaCO2 and pH remained unchanged. The magnitude of the change in PaO2 correlated with the change in AaPO2 on room air (r = 0.77; p < 0.01) but not with the change in AaPO2 on 100% oxygen. It is concluded that in adult patients with ES there is a significant decrease in PaO2 and SaO2 when they change from the sitting to the supine position. A ventilation-perfusion (V/Q) distribution abnormality and/or a diffusion limitation phenomenon rather than an increase in true shunt may be the mechanisms responsible for this finding. The response to nasal O 2 we observed warrants a trial with long-term nocturnal oxygen therapy in these patients.