Impending paradoxical embolism from atrial thrombus: correct diagnosis by transesophageal echocardiography and prevention by surgery

Successful surgical treatment of impending paradoxical embolism with pulmonary embolism and myocardial infarction

BACKGROUND

Paradoxical embolism is a rare cause of acute arterial occlusion. This phenomenon arises when embolic material travels from the venous system crosses an abnormal shunt such as patent foramen ovale, atrial septal defects, ventricular septal defects, or pulmonary arteriovenous malformations, into the arterial system. Impending paradoxical embolism refers to the presence of an entrapped thrombus in the patent foramen ovale.

CASE PRESENTATION

We report a case of a 68-year-old female patient who presented with an impending paradoxical embolism, alongside both concomitant pulmonary embolism and myocardial infarction with ST-segment elevation. Swiftly addressed through emergency cardiac surgery and systemic anticoagulation, the patient's condition was effectively treated.

CONCLUSIONS

While the ideal treatment strategy for impending paradoxical embolism remains a topic of debate due to limited and inconclusive evidence, emergent open surgery should be contemplated in patients as it signifies a critical clinical emergency.

Quadri-Chamber Thrombi and Impending Paradoxical Embolism: Thrombus in Transit Through Patent Foramen Ovale

Thrombus-in-transit through patent foramen ovale (PFO) is an extremely rare diagnosis that can often be associated with pulmonary embolism. Currently, data exists to guide management options; however, there is no medical consensus with regard to the optimal treatment strategy for thrombus-in-transit through PFO.

A multidisciplinary approach for a patient with cardiogenic shock from pulmonary embolism with concomitant impending clot in transit trapped in PFO

Impending paradoxical embolism (IPDE) is a right heart thrombus (RHT), in times of elevated pulmonary arterial pressure, that is trapped in a patent foramen ovale (PFO) Myers et al. (2010) (3). We present a case that highlights our multidisciplinary approach in a patient with IPDE with cardiogenic shock from pulmonary embolism (PE).

An Unusual Case of Impending Paradoxical Embolism Through a Patent Foramen Ovale in Renal Cell Carcinoma

Impending paradoxical embolism (IPDE) is a clinical emergency with adverse outcomes. Due to its rarity, larger research cannot be obtained to provide definitive therapy alternatives. We report a case of a tumor embolus from a renal cell carcinoma (RCC) that caused a right atrial mass, pulmonary embolus, and impending paradoxical embolus via a patent foramen ovale (PFO) and its management.

Impending paradoxical embolism: about two cases. 3D echocardiographic imaging and discussion of treatment options

INTRODUCTION

Impending paradoxical embolism (IPDE) is a rare condition where a thrombus straddles the foramen ovale with a high risk of arterial embolism.

CASES REPORT

We report two cases of impending paradoxical embolism, an uncommon condition with a high mortality rate. The first in a young woman with acute right heart failure operated emergently, the second, in an old and frail lady presenting an ischemia of the left arm, treated by anticoagulants. 3 D echocardiography imaging is presented and treatment modality is discussed.

CONCLUSION

Emergent treatment is mandatory for IPDE, a serious disease with a high early mortality. This paper is a reminder of how to deal with such a rare condition.

Thrombus in transit through a patent foramen ovale: catch it if you can-a case report

Background

Patent foramen ovale (PFO) is one of the most common congenital heart defects, but the finding of a thrombus in transit (TIT) through a PFO is extremely rare. It is a therapeutic challenge, and systemic anticoagulation, cardiac surgery, or fibrinolysis should be considered.

Case summary

A 43-year-old woman was admitted with intermediate-high-risk pulmonary embolism. Transthoracic echocardiogram revealed a large right atrial mobile mass that crossed the interatrial septum through a PFO, compatible with TIT, and the patient was started on unfractionated heparin. The diagnosis was confirmed by transoesophageal echocardiogram (TOE). However, during TOE probe removal, the patient developed dyspnoea, sudoresis, and peripheral desaturation, and new image acquisition revealed sudden mass disappearance. Due to the possibility of paradoxical embolization associated with Valsalva manoeuvre, fibrinolysis with alteplase was promptly started. The patient had no signs of embolic or haemorrhagic complications and remained clinically stable. She was discharged on warfarin and then underwent percutaneous transcatheter closure of PFO.

Discussion

The treatment strategy of a TIT through a PFO is controversial, but surgery might be the most appropriate treatment for haemodynamically stable patients, while thrombolysis should be used in cases of haemodynamic instability. Transoesophageal echocardiogram is generally a safe procedure but pressure changes associated with Valsalva manoeuvre may induce embolization of a TIT and attention should be given to patient sedation and tolerance. After complete embolization of a TIT, emergent thrombolysis may be the only treatment option, in order to prevent disastrous consequences related to paradoxical embolism.

The pivotal role of PFO in paradoxical embolism following venous sclerotherapy: a unique case report with pathological correlations

Background 

Vein sclerosing therapy for varicose veins remains an extremely popular procedure. Cerebrovascular accidents can be a serious complication. A patent foramen ovale (PFO) can act as a conduit to the arterial circulation, which could explain the adverse neurologic consequence of this procedure. This case provides pathologic evidence of this concept.

Case summary 

A 66-year-old female presented with syncope after undergoing varicose vein sclerotherapy. A computed tomography angiography of the head and neck in the emergency room revealed an occluded right distal M1 middle cerebral artery. Clot retrieval was performed with final pathology revealing amorphous material consistent with an exogenous agent, polidocanol foam, which was used for the patient’s vein sclerotherapy. A transthoracic echocardiogram and transoesophageal echocardiogram showed a PFO, which was ultimately closed percutaneously.

Discussion 

In a quarter of the population, lack of closure of the intrauterine interatrial shunt leads to the existence of a PFO. This direct communication between the atria provides an anatomical conduit for paradoxical emboli and eventually infarction of affected tissues. While a paradoxical embolism is an uncommon cause of acute arterial occlusion, it can have catastrophic sequelae. Historically, the presence of an arterial thrombus from the venous circulation has been difficult to establish unless the thrombus is visualized in transit through a PFO. Complications from vein sclerotherapy have been reported in the literature and include transient ischaemic attacks and strokes, however, this is the first case to provide pathological proof of a paradoxical embolism, which ultimately resulted in percutaneous closure of the PFO.

Silent embolism of a large thrombus in transit through the patent foramen ovale: a case report

Background 

Detection of a thrombus in transit through a patent foramen ovale (PFO) is extremely rare due to the transient nature of the process. We report an unusual case of a large, paradoxical embolus in transit seen on echocardiography through a PFO that was not found upon atriotomy.

Case summary 

An 80-year-old woman presented to the emergency room with shortness of breath and right leg pain. She was haemodynamically stable on presentation, and her physical exam was unremarkable. An ultrasound of her right leg revealed a deep vein thrombus in the posterior tibial vein, and chest computed tomography angiography showed saddle pulmonary emboli. Transthoracic echocardiogram identified a large thrombus in transit through a PFO, which was confirmed with a transoesophageal echocardiogram (TOE). She underwent an emergency embolectomy. The thrombus in transit was confirmed by TOE prior to bypass initiation; however, no thrombi were found in any chambers of the heart following atriotomy. Her postoperative recovery was uneventful. She had no focal neurological deficits or any apparent signs of large vessel embolization.

Discussion

Cases of silent embolism have been reported in the literature, although they are rare. To our knowledge, this is the first case of a large thrombus in transit through a PFO in an elderly female that was confirmed by an intra-operative TOE but could not be found following atriotomy, with no obvious clinical signs of embolization.

Impending paradoxical embolism

An impending paradoxical embolism (IPDE) is seldom observed in clinical practice. We report a case of IPDE in a 67-year-old female with severe dyspnea and hypotension, which was detected and successfully treated with emergent cardiac surgery. The optimal treatment is still controversial. We believe that emergent surgery always should be considered in patients with IPDE. <Learning objective: We report a rare case of an impending paradoxical embolism in a 67-year-old female with severe dyspnea, which was successfully treated with emergent cardiac surgery. An emergent open surgery always should be considered in patients with impending paradoxical embolism.>.

A Thrombus on a Journey: A Massive Thrombus in Transit With Cerebral, Coronary, and Pulmonary Embolization

Impending paradoxical embolism is a biatrial thrombus in transit across a patent foramen ovale. It constitutes a rare clinical condition, possibly associated with multiple embolization and high mortality. We report the exceptional case of a 71-year-old-man presenting a giant impending paradoxical thrombus, complicated with pulmonary, cerebral, and coronary embolization. The patient underwent urgent surgery and was finally discharged without complications.

Thrombus in transit through a patent foramen ovale: An unusual cause of cardiac embolism

A 78-year-old woman with a history of transient ischemic attack was admitted for sudden aphasia. In order to assess the potential cardioembolic source an echocardiogram was performed, which revealed a large mass consistent with a thrombus in transit through a patent foramen ovale. Because of the high risk of systemic embolism, emergent surgical thrombectomy was performed with the intention to discharge the patient safely without any new embolic events. This case report highlights the importance of echocardiography in the evaluation of cardioembolic stroke and the requirement of an emergent approach in case of impending paradoxical embolism.

Impending Paradoxical Embolism: Perioperative Management and Role of Transesophageal Echocardiography

Impending paradoxical embolism is a rare but potentially life-threatening complication of venous thromboembolism that is usually associated with acute pulmonary embolism and a right to left atrial shunt. Patients may have associated right ventricular pressure or volume overload with subsequent failure. Transesophageal echocardiography is the preferred diagnostic test of choice in this patient group. Definitive management has yet to be clearly defined. However, emergent surgical removal of the entrapped intracardiac blood thrombus may be necessary. In this article, we review a case of impending paradoxical embolism managed surgically and describe the perioperative anesthetic considerations in this patient population, along with the role of intraoperative transesophageal echocardiography.

Role of 3D transesophageal echocardiography in transcatheter closure of atrial septal aneurysms

BACKGROUND

Three dimensional transesophageal echocardiography (3DTEE) is superior to two dimensional transesophageal echocardiography (2DTEE) as it provides all atrial septal information from a single view.

AIM

To evaluate 3DTEE role in analysis of atrial septal aneurysm (ASA) and in device closure guiding.

METHODS

Three dimensional transesophageal echocardiography were recorded with Vivid*E9,GE system over 14 months. ASAs were classified into 4 types (A: with PFO, B: with one ASD, C: with 2 ASDs, and D: with multiple fenestrations). Each aneurysm was assessed according to its type, shape, dimensions, orientation, aneurysmal tissue, and the surrounding rims. All patients passed to transcatheter aneurysm closure.

RESULTS

A total of 26 patients with ASAs were assessed (7 imperforated aneurysms excluded). The remaining 19 patients' age was 12.84 ± 5.82years. Four patients had type A aneurysms, 6 had type B, 4 had type C, and 5 had type D. 3DTEE demonstrated oval aneurysms in 17 patients. The orientation was oblique in 8 patients, vertical in 7, and horizontal in 4. The ASAs dimensions were 23.5 ± 5.1, 23.2 ± 5.1, and 22.0 ± 4.0 mm for oblique, vertical, and horizontal axes. Percutaneous closure succeeded in 18 patients. Balloon sizing was used in 4 patients. Devices used were: In type A:PFO devices, in type B:ASO devices, in type C:two patients required two ASO devices in each patient and two patients required one cribriform device, and in type D:Cribriform devices used for three patients, PFO for one and ASO for one. LA, LUPV, and RUPV approaches were used. Aspirin was received for 6 months.

CONCLUSION

Three dimensional transesophageal echocardiography helps to select aneurysms suitable for transcatheter closure, select the suitable devices, and guide the transcatheter procedure.

Saddle Pulmonary Embolus Caught in Transit across a Patent Foramen Ovale

Impending paradoxical embolism (IPE) also described in the literature as thrombus straddling a patent foramen ovale (PFO) or paradoxical embolus in transit is a rare condition when thrombus (originating mostly in deep veins of lower extremities) embolized to the heart gets caught in PFO or in atrial septal defect without systemic embolization. We present a case of a 39-year-old female on oral contraceptive pills who presented to the emergency department with chief complaint of dyspnea and chest pain. She was found to have saddle pulmonary embolus (PE) extending through PFO to left atrium and into the left ventricle. Patient underwent emergent open pulmonary embolectomy, removal of right and left atrial thrombi, and closure of patent foramen ovale. She tolerated the surgery well and was discharged home on chronic anticoagulation therapy.

Pulmonary embolism and infarction with a paradoxical thrombus visualised in both atria

A 59-year-old woman presented with a sudden onset of breathlessness and chest pain. An echocardiography and CT scan showed pulmonary embolism and infarction with a paradoxical thrombus visualised in both atria. For haemodynamically stable patients, the optimal management strategy is poorly defined. Three main strategies were considered: surgical thrombectomy, thrombolysis and anticoagulation. Surgery with reversal of anticoagulation may lead to further coagulation and increased risk of bleeding complications. The significant pulmonary hypertension and right ventricular infarction raised the prospect of difficult weaning from cardiopulmonary bypass following thrombectomy. Thrombolysis, which has significant mortality rate, and systemic embolisation including pulmonary infarction with haemorrhagic transformation were also contraindications. A multidisciplinary approach was adopted and anticoagulation was therefore believed to be the safest and effective approach. Here, the use of anticoagulation alone was fortunately successful but could as easily end in disaster. This approach should be considered the ideal paradigm to yield optimum outcomes.

Patent foramen ovale closure to prevent secondary neurologic events

In October of 2016 the United States Food and Drug Administration approved the Amplatzer Patent Foramen Ovale (PFO) occluder device for use in patients with cryptogenic stroke, to reduce the risk of recurrent stroke. This event followed 15years of off-label use of atrial septal occluder devices, 3 randomized trials, and enormous controversy over the efficacy of this procedure. While none of the trials reached the primary endpoint needed to prove the efficacy of PFO closure in preventing recurrent stroke, meta-analyses and 5-year follow-up of 1 trial suggest that PFO closure decreases the risk of recurrent stroke, especially in sub-groups with large shunts and atrial septal aneurysms, and especially when the Amplatzer device (rather than other devices) is used. While the relative reduction in stroke associated with PFO closure is large (about 50%), the absolute reduction is low (1-2%) and must be balanced against complications of the procedure (about 3%). Thus, PFO closure is restricted to patients with cryptogenic stroke, and depends heavily on patients' personal preferences. Uncertainties about the etiology of stroke in patients with PFO and the efficacy of PFO closure cause a difficult problem for the internal medicine specialist. At one extreme the internist may wonder if every patient with a documented PFO should be referred to a cardiologist. At the other extreme, supported by specialty society guidelines, internists may conclude that PFO closure is rarely necessary. In this paper we review the current status of PFO closure and suggest a rational strategy for this procedure.

Saddle Pulmonary Embolism with Thrombus in Transit across a Patent Foramen Ovale

This is the case of a 25-year-old obese man who presented with acute shortness of breath, chest pain, and palpitations. Of note, he lives a sedentary lifestyle and was recently hospitalized for incision and drainage of a left foot abscess. On presentation he was tachypnoeic, tachycardiac, and hypoxic but blood pressure was stable. Laboratory studies were significant for elevated D-dimer and mildly increased troponin. On further investigation he was found to have a saddle pulmonary embolism with massive clot burden. Echocardiogram revealed thrombus in transit and McConnell's sign. He underwent surgical embolectomy and closure of a patent foramen ovale. This is a particularly rare case, especially in such a young patient. Because this is a rare diagnosis, with insufficient data, there is no formally established treatment guideline. However, in patients who are good surgical candidates, studies have shown better outcome with surgical embolectomy as compared to anticoagulation alone or thrombolysis.

Thrombus in Transit with Isolated Paradoxical Embolism to the Subclavian Artery

Paradoxical embolism is an uncertain entity triggering significant debate. A thrombus in transit across a patent foramen ovale is a rarity, a potential catastrophe with nonuniform management recommendations, and theoretically the objective proof that paradoxical embolism is real. We present a case in a postoperative setting, with a thrombus in transit across a patent foramen ovale. Pulmonary embolization was clinically silent and diagnosed incidentally, and systemic embolization was isolated but extensive to the subclavian artery. The case stimulates many unanswered questions and possible scenarios.

Surgical treatment of a massive bilateral pulmonary embolus due to an entrapped thrombus in a patent foramen ovale: a case report

INTRODUCTION

Entrapped thrombus in a patent foramen ovale is a rare form of right heart thromboembolism. Various treatments have been used, such as anti-coagulation and thrombolytic therapy, vena cava filter, percutaneous thrombectomy and surgical embolectomy.

CASE PRESENTATION

A 60-year-old Kosovan woman was admitted to our hospital with a massive bilateral pulmonary thromboembolism, entrapped thrombus in the patent foramen ovale and severe right ventricular dysfunction. The patient underwent on-pump beating-heart removal of the intracardiac thrombus and bilateral pulmonary embolectomy with the use of a Fogarty catheter. The patient's post-operative course was uneventful. In this report, we describe for the first time in this pathology, to the best of our knowledge, a surgical strategy that seems to offer an excellent outcome in patients with severe right ventricular dysfunction.

CONCLUSIONS

The chosen surgical technique, consisting of on-pump open beating-heart surgery, is a unique procedure in the treatment of an acute pulmonary thromboembolism and entrapped thrombus in a patent foramen ovale.

Entrapped thrombus in a foramen ovale causing pulmonary emboli treated with emergent surgery. Literature review

A 60-year-old woman was admitted due to massive bilateral pulmonary thromboembolism and entrapped thrombus in the patent foramen ovale and severe right ventricular dysfunction. The patient underwent on-pump/beating heart removal of the intracardiac thrombus and bilateral pulmonary embolectomy. The postoperative course was uneventful. The chosen surgical strategy seems to offer excellent outcome in patients with severe right ventricular dysfunction.

Decline in mean platelet volume in patients with patent foramen ovale undergoing percutaneous closure

Introduction

The presence of patent foramen ovale (PFO) is considered a possible cause for cryptogenic stroke. The mechanism underlying the ischaemic neurological events in the presence of PFO has not been firmly established. The purpose of this study was to compare: (1) the mean platelet volume levels in PFO patients with and without a cryptogenic stroke, and (2) pre- and post-procedural mean platelet volumes (MPV) in patients undergoing percutaneous PFO closure.

Methods

Sixteen PFO patients undergoing percutaneous closure to prevent recurrent ischaemic events and 15 asymptomatic patients with PFO were enrolled in the study. Mean platelet volume was compared between patients with and without a history of stroke. We also compared pre- and postprocedural MPV levels in patients undergoing percutaneous PFO closure.

Results

Mean platelet volume, which is a marker for platelet activity, was similar in PFO patients with and without stroke (9.34 ± 1.64 vs 9.1 ± 1.34 fl; p = 0.526). Interestingly, MPV decreased significantly after percutaneous closure compared to pre-procedural levels (9.34 ± 1.64 vs 8.3 ± 1.12 fl; p = 0.001).

Conclusion

Our findings suggest interatrial communication through a PFO may be related to increased MPV and increased platelet activity.

Large serpiginous thrombus straddling the patent foramen ovale and traversing through mitral and tricuspid valves into both ventricles: a therapeutic dilemma of impending paradoxical embolism and recurrent pulmonary embolism

A 51-year-old male with history of resected renal cell carcinoma and prior pulmonary embolism presented with tachypnea, tachycardia and progressive dyspnea on exertion. Chest computed tomography revealed bilateral acute pulmonary embolism. Transthoracic echocardiogram showed severe pulmonary hypertension with severe cor-pulmonale and presence of a large worm-like thrombus extending across the foramen ovale, entering both ventricles through the mitral and tricuspid valves. The risks of anti-coagulation, pharmacologic thrombolysis, and surgical thrombectomy, in a hemodynamically stable patient, posed a significant therapeutic dilemma. Ultimately, a collective decision was made to start anticoagulation, without incident. At 1 month follow up, complete resolution of the intracardiac thrombus, pulmonary hypertension, and cor-pulmonale were observed with full clinical recovery of the patient.

Impending paradoxical embolism: have we lost the clot?

Impending paradoxical embolism is a rare diagnosis that requires urgent treatment. We present a case where surgical thromboembolectomy was undertaken. The thrombus vanished from view on transesophageal ultrasound and was presumed to have undergone embolisation while bypass was established. Unexpectedly, it was found tangled in the superior vena cava cannula apertures.

Thrombus in Transit through Patent Foramen Ovale

A thrombus in transit through a patent foramen ovale (PFO) with impending paradoxical embolism is an extremely rare event. Due to its transient nature, it is unable to identify the thrombus, and most of the cases have been reported at autopsy. We are reporting a case of thrombus straddling the foramen ovale which was diagnosed by echocardiography and treated surgically. Through this personal case, an exhaustive review of the literature was performed. There were 88 cases reported. We concluded that there is no medical consensus about the best option for treatment. Nevertheless, surgery, which is associated with fewer complications of recurrent embolic events than those of thrombolysis and anticoagulation, appeared to be the best approach in patients who are not at a high surgical risk. Anticoagulant treatment appears to be an acceptable therapeutic alternative to surgery, particularly in patients with comorbidities who are at high surgical risk and for patients with small PFO. Thrombolysis is linked to the highest mortality, which could be explained by the severity of the patient's initial presentation. In conclusion, and after the cumulative effects of these case reports, we propose a diagram consisting of the use of the three therapeutic options in the different clinical scenarios.

Large embolus in transit - an unresolved therapeutic dilemma (case report and review of literature)

Floating right heart thrombus, also known as "emboli in transit" is a potentially fatal condition, of varying etiology and usually coexisting with massive pulmonary embolism. Although the mortality rate is as high as 40%, there are no established therapeutic guidelines. A case is presented of an 84 year old female with a history of colon cancer and coronary artery disease who presented with sudden onset unresponsiveness. She was intubated in the ED and started on intravenous pressor support. A free floating large right ventricular thrombus and dilated right ventricle were noted on transthoracic echocardiogram (TTE). She was managed medically with good short term outcome. Floating right heart thrombus is a rare occurrence. Recognition of signs and symptoms along with early TTE is critical for diagnosis and consideration of treatment modality. The existing literature does not offer a clear consensus for management of pulmonary embolism with co-existing mobile intra-cardiac thrombus. Choice of treatment is crucial and should be considered on a case-by-case basis after careful assessment of indications, contraindications, risks and benefits.

Impending paradoxical embolism presenting as myocardial infarction

We present a spectrum of findings with transthoracic echocardiography, coronary angiography, and open surgical exploration in a 54-year-old man who presented with an acute ST segment elevation myocardial infarction and was diagnosed with impending paradoxical emboli. He underwent successful surgical removal of the thrombus.

LEARNING OBJECTIVE

Impending paradoxical embolism, a biatrial thromboembolus in transit across a patent foramen ovale, is associated with a 20% mortality rate. Very rarely does it present as a ST segment elevation myocardial infarction. The optimal management (medical or surgical) for those who present with it remains a subject of debate, although surgery has been associated with less systemic embolization.

Impending paradoxical embolism: a case report

BACKGROUND

A thrombus straddling a patent foramen ovale (i.e., impending paradoxical embolism) is a very rare event. Most cases have been reported at autopsy only after finding a patent foramen ovale and arterial emboli. Patent foramen ovale in the population is common.

OBJECTIVES

The objective of this case report is to remind physicians that common presentations can have uncommon causes. Some of these uncommon causes are easy to find and may significantly change outcomes if treated early.

CASE REPORT

We present the case of a dyspneic patient with concomitant pulmonary embolism, deep vein thrombosis, and impending paradoxical embolism. Emergency Physicians should be aware that dyspnea may be the only initial symptom. Although dyspnea may be linked to a pulmonary embolus, it may not represent the entire clinical picture. A thrombus formed within a patent foramen ovale portends the possibility of a larger pulmonary embolus and an arterial embolus.

CONCLUSION

Early detection of an impending paradoxical embolism may result in an improved outcome. Treatment choices consist of anticoagulation, thrombectomy, or thrombolysis. Choice of treatment is difficult but should be made quickly to reduce the possibility of adverse patient outcomes.

Double-edged sword in the heart: trapped deep venous thrombus in a patent foramen ovale

Trapped thrombus in a patent foramen ovale is a rare condition. Echocardiography is the main tool for diagnosis and for determination of the treatment to choose. There are a number of treatment options for trapped deep venous thrombus in a patent foramen ovale, including surgical thrombectomy, thrombolytics, and anticoagulant therapy. All patients should be evaluated individually, because the systemic and pulmonary thromboembolism risk of all treatment options is like a 'double-edged sword'. Here, we report a case of a patient with trapped thrombus in the patent foramen ovale detected by echocardiography, and successfully treated with surgical thrombectomy under extracorporeal circulation.

Recurrent episodic hypoxaemic respiratory failure following a stroke

A 68-year-old man with no cardiovascular risk factors was admitted with a stroke because of multiple brain infarcts in different vascular territories. He required mechanical ventilation for hypoxia as a result of aspiration pneumonia. Subsequent recovery was hindered by episodic, unexplained hypoxia. Investigations excluded pulmonary embolism, pulmonary hypertension and severe lung diseases. Transthoracic echocardiography (TTE) with saline bubble contrast showed mild, delayed, right-to-left shunting, thought to represent an insignificant, intrapulmonary, non-cardiac shunt. Hypoxic episodes worsened, requiring admission from community rehabilitation hospital to our centre and another period of mechanical ventilation. Elevated alveolar-arterial gradients indicated a non-hypoventilatory cause. Repeat TTE bubble contrast study and transoesophageal echocardiography (TOE) demonstrated a patent foramen ovale (PFO) with large shunt potential, associated with an aneurysmal interatrial septum. This provided a unifying explanation for cryptogenic stroke and recurrent hypoxaemia. After percutaneous PFO closure hypoxic episodes ceased and he returned successfully to rehabilitation.

High frequency of silent pulmonary embolism in patients with cryptogenic stroke and patent foramen ovale

BACKGROUND AND PURPOSE

Deep vein thrombosis and pulmonary embolism (PE) prove venous embolic activity and enforce the suspicion of paradoxical embolism in patients with stroke with patent foramen ovale. Because it has implications in secondary prevention, we investigated the frequency of silent PE in such a cohort of patients.

METHODS

Patients with cryptogenic stroke or transient ischemic attack and patent foramen ovale who underwent a ventilation perfusion scintigraphy were identified from a stroke registry. Blinded from clinical data, ventilation perfusion scintigraphy scans were re-evaluated independently by 2 experts. Patients showing at least a subsegmental defect were considered as having silent PE. Factors potentially associated with PE were analyzed.

RESULTS

The evaluation included 151 patients. Median age was 55.2 years and 59.9% were male. In 56 (37%) patients, silent PE was found; a deep vein thrombosis was evident in 11 (7%) patients. Atrial septal aneurysm was identified in 39 patients and hypermobile atrial septum in 37 patients. Atrial septal aneurysm and hypermobile atrial septum were independently associated with PE. In females, intake of oral contraceptives showed certain association with PE (6 of 25 versus 3 of 40; P=0.07).

CONCLUSIONS

Silent PE frequently occurs in patients with cryptogenic stroke and patent foramen ovale, particularly when atrial septal aneurysm or hypermobile atrial septum are present.