Paradoxical Embolism

Association between patent foramen ovale and chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

Patent foramen ovale (PFO) is a defect in the intra-atrial septum that occurs when the foramen ovale does not close postnatally. Chronic obstructive pulmonary disease (COPD) is a respiratory condition that causes airflow obstruction.

OBJECTIVE

This systematic review aimed to consolidate current evidence on the association between PFO and COPD outcomes.

METHODS

We searched Medline, Embase, and Cochrane databases from inception to November 2023 for studies conducted among adults who have been diagnosed with COPD and underwent testing for PFO. A structured data extraction sheet was created to collect data from selected studies. A meta-analysis with a random effects model was considered when feasible.

RESULTS

The initial search identified 765 records. After screening for eligibility, we included six cross-sectional and three case report studies. In cross-sectional studies, patients with COPD had almost three times higher odds of having PFO than controls (OR = 2.72, 95 % CI: 1.57 to 4.70, I2 =0 %). When comparing COPD patients with and without PFO, the pooled mean difference was -2.99 mmHg; 95 % CI:5.55 to -0.44, I2 =77 %) in oxygen saturation (SaO2), -6.85 mmHg (95 %CI:11.71 to -2.39, I2 =35 %) in arterial oxygen partial pressure (PaO2) and 9.65 mmHg (95 %CI: 3.38 to 12.92, I2 =0 %) in pulmonary arterial pressure.

CONCLUSIONS

Evidence, based on a few and small size studies, indicates that PFO presence may be associated with worse outcomes in COPD patients. The long-term impact of these findings on COPD outcomes and the need for identifying high-risk patients for PFO screening should be evaluated.

Stroke recurrence after transcatheter PFO closure in patients with cryptogenic stroke

BACKGROUND

Patent foramen ovale (PFO) closure is recommended for secondary prevention of cryptogenic stroke. However, data on long-term results are limited. We aimed to evaluate safety and efficacy of transcatheter PFO closure and predict neurologic recurrence.

METHODS

Data from patients undergoing PFO closure between 2010 and 2015 were collected to assess the combined endpoint of transient ischemic attack (TIA), stroke, or death from stroke at short- and long-term follow-up.

RESULTS

330 patients were included, mean age was 49 (±12) years, and 55.5% were male. Before PFO closure, 86% experienced a stroke and 19% multiple neurological events. Procedure-related complications occurred in 2.4% of patients. Over a median follow-up of 10 years, the combined endpoint occurred in 3.6%, with a recurrence rate of 0.38 per 100 patient-years. Freedom from the combined endpoint at 5 and 10 years was 97.5% and 96.2%, respectively. New-onset atrial fibrillation was detected in 3%. The Risk of Paradoxical Embolism (RoPE) score (adjHR: 0.68; p = 0.032), the PFO-Associated Stroke Causal Likelihood (PASCAL) classification system (adjHR: 0.37; p = 0.042), and a history of prior neurological events (adjHR: 9.94; p < 0.001) were independent predictors of future recurrent neurologic events. Age, sex, and cardiovascular risk factors did not influence outcomes.

CONCLUSION

In this real-world cohort, transcatheter PFO closure was associated with low long-term recurrence of neurologic events, especially cryptogenic strokes. The RoPE score, the PASCAL score, and history of previous neurological events were predictive of recurrent events. This study supports the safety and efficacy of PFO closure for secondary prevention of cryptogenic strokes, and underscores the importance of patient selection.

Thrombus rooting in the pulmonary arteriovenous fistula in a patient with cryptogenic stroke, a case report

BACKGROUND

Cryptogenic stroke constitutes approximately 40% of ischemic strokes in young adults, imposing a significant socioeconomic burden. However, the source of embolus has been specifically investigated in a few number of studies. In this report, We document the first case of a cryptogenic stroke associated with a pulmonary arteriovenous fistula (PAVF), providing evidence of mural thrombus formation within the PAVF vessel.

CASE PRESENTATION

A 52-year-old woman present with sudden-onset blurriness, right-sided numbness and paresthesia, speech difficulties, and salivation. It was confirmed as embolic stroke with magnetic resonance imaging. No evidence of cerebral arteriosclerosis or stenosis was identified, and cardiogenic embolism was ruled out. Further investigation was conducted to determine the cause of the anomalous embolism. A right-to-left shunt was detected using trans-cranial Doppler and transthoracic echocardiogram. Pulmonary arteriography revealed a simple PAVF. Optical coherence tomography (OCT) was used to examine the interior structure of the fistula vessel, revealing the presence of mural thrombus and a rough endangium.

CONCLUSIONS

This case provides the initial evidence regarding the location of thrombus formation assessed and raises the awareness of a potential emboligenic mechanism in PAVF.

Selection of patients for percutaneous closure in nonlacunar cryptogenic stroke associated with patent foramen ovale. Data from the NORDICTUS cooperative registry

INTRODUCTION

There is an extending use of percutaneous closure of patent foramen ovale (PFO) as therapy for PFO-associated cryptogenic strokes. The aim of our study was to investigate the clinical practice of percutaneous closure of PFO and to analyse the variables for decision-making on the selection of patients for this procedure.

METHOD

A prospective observational multicentric survey was conducted using all the cases of cryptogenic stroke/transient ischaemic attack associated with PFO recorded in the NORDICTUS hospital registry during the period 2018-2021. Clinical data, radiological patterns, echocardiogram data and factors related to PFO-associated stroke (thromboembolic disease and paradoxical embolism criteria) were recorded. The indication for closure was analysed according to age (≤/> 60 years) and the characteristics of the PFO.

RESULTS

In the group ≤ 60 years (n = 488), 143 patients (29.3%) underwent PFO closure. The most influential variables for this therapy were detection of a high-risk PFO (OR 4.11; IC 2.6-6.5, P < .001), criteria for paradoxical embolism (OR 2.61; IC 1.28-5.28; P = .008) and previous use of antithrombotics (OR 2.67; IC 1.38-5.18; P = .009). In the > 60 years group (n = 124), 24 patients had PFO closure (19%). The variables related to this option were history of pulmonary thromboembolism, predisposition to thromboembolic disease, paradoxical embolism criteria, and high-risk PFO.

CONCLUSIONS

The detection of a high-risk PFO (large shunt, shunt with associated aneurysm) is the main criterion for a percutaneous closure-based therapy. Other conditions to consider in the eligibility of patients are the history of thromboembolic disease, paradoxical embolism criteria or the previous use of antithrombotics.

Valsalva Leading to Pain in the Left Arm: A Case of Paradoxical Embolism

Paradoxical embolism (PDE) secondary to a patent foramen ovale (PFO) is an underdiagnosed condition with potentially severe clinical outcomes, including stroke, myocardial infarction, migraines, and peripheral arterial embolism. PFO is typically asymptomatic and often requires a high index of suspicion for a proper diagnosis. We report a case of a 36-year-old male smoker with a medical history significant for pulmonary thromboembolism, deep vein thrombosis (DVT) of the right lower extremity (RLE), type 1 diabetes mellitus (T1DM), and coronary artery disease (CAD). The patient presented with sudden-onset left arm pain after recreational activity. Physical examination revealed a hemodynamically stable individual with findings suggestive of ischemia in the fourth and fifth digits of the left hand. Initial diagnostic workup including duplex ultrasound, CT angiography (CTA), and transthoracic echocardiography (TTE) suggested left ulnar artery thrombosis, with TTE negative for cardiac septal abnormalities. Following the thrombectomy, he experienced complete symptom resolution upon discharge. However, two weeks later, he returned with identical symptoms and clinical findings. Subsequent investigations, including transesophageal echocardiography (TEE) with a bubble study, confirmed the presence of a PFO. The recurrent thrombotic event was attributed to a PDE facilitated by the PFO. Definitive management involved PFO closure using a septal occluder device, resulting in the successful resolution of symptoms. This report highlights the importance of considering PFO in patients with unexplained recurrent embolic events and underscores the value of advanced imaging modalities, such as TEE, in establishing the diagnosis.

Comparing the Risk of Epilepsy in Patients With Simple Congenital Heart Diseases: A Prospective Cohort Study

AIMS

Simple congenital heart diseases (CHD) are associated with various central nervous system diseases, including epilepsy. This study aimed to compare the risk of epilepsy in patients with different types of simple CHD.

METHODS

In this prospective cohort study, from January 2008 to June 2022, patients with atrial septal defect (ASD), patent foramen ovale (PFO), ventricular septal defect (VSD), and patent ductus arteriosus (PDA) were recruited at the Registration Center of CHD in West China Hospital. Follow-up was conducted yearly until the diagnosis of epilepsy, loss to follow-up, or end of study. The outcomes included a comparison of epilepsy incidence according to different simple CHD types and a risk assessment of developing epilepsy. Multivariable Poisson regression was performed to adjusted factors of demographics and disease history.

RESULTS

Of 10,914 patients who met the inclusion criteria, 108 were diagnosed with epilepsy at an average follow-up of 2.19 years. Epilepsy incidence in patients with PFO, VSD, PDA, and ASD was 8.58/1000, 4.85/1000, 3.98/1000, and 2.63/1000 person-years, respectively. Compared with ASD patients (reference group), the risk ratios (95% confidence intervals) in patients with PFO, VSD, and PDA were 3.28 (2.00-5.43), 1.47 (0.79-2.68), and 1.46 (0.70-2.82), respectively. Subgroup analyses determined that patients with simple CHD who underwent CHD surgery demonstrated a lower risk of epilepsy than those who did not.

CONCLUSION

Among the major types of simple CHD, PFO was associated with a significantly higher risk of epilepsy, while the risk was reduced in those who underwent PFO closure procedures.

Massive Central Pulmonary Embolism with Riding Embolus and Concomitant Aortic Arch Embolism-Should We Diagnose Patients Earlier for Blood Clotting Disorders? Case Report

Paradoxical embolism occurs when a clot originates in the venous system and traverses through a pulmonary or intracardiac shunt into the systemic circulation, with a mortality rate of around 18%. The risk factors for arterial embolism and venous thrombosis are similar, but different disease entities can lead to a hypercoagulable state of the blood, including antithrombin III (AT III) deficiency. We report the case of a 43-year-old man with a massive central pulmonary embolism with a rider embolus and concomitant aortic arch embolism with involvement of the brachiocephalic trunk, bilateral subclavian and axillary arteries, and the right vertebral artery, followed by a secondary ischaemic stroke. The Pulmonary Embolism Response Team (PERT) consulted the patient on several occasions; he was treated initially with an intravenous infusion of unfractionated heparin under activation partial thromboplastin time (APTT) and AT III substitution. After several days of hospitalisation and the conversion of pharmacotherapy to oral anticoagulants, the patient was discharged home in a stable condition with recommendations for further follow-up in appropriate clinics. This case highlights the role of in-depth diagnostics for coagulation disorders in patients after pulmonary embolism, especially without known risk factors.

Bilateral thalamic infarction with posterior cerebral artery variant (the arcade artery): A case report

RATIONALE

Bilateral thalamic infarction is a rare type of posterior circulation stroke, and it often presents with a reduced level of consciousness in the elderly. Arteriosclerosis is the primary etiology of bilateral thalamic infarction, including conditions such as native vessel stenosis or arterial-to-arterial embolism. Cardiogenic or paradoxical embolism can also lead to thrombosis of the perforator branches innervating the thalamus, and these emboli tend to disintegrate and lead to multiple lesions, even in elderly patients.

PATIENTS CONCERNS

A 69-year-old man presented to our emergency room with sudden onset of drowsiness lasting for 2 days. A computed tomography scan revealed bilateral hypodense thalamic lesions, which resembled artery of Percheron infarcts. Magnetic resonance imaging confirmed cerebral infarction in the posterior circulation. Magnetic resonance angiography and diagnostic digital subtraction angiography suggested a suspicious embolus obstructing the junction between the arcade artery and the left posterior cerebral artery, which had further migrated. Echocardiography, 24-hour Holter monitoring, and deep venous ultrasonography were all negative; however, transesophageal echocardiography revealed a patent foramen ovale.

DIAGNOSIS

Paradoxical embolism is a rare occurrence in older adults. However, when considering the etiology of stroke in this patient, paradoxical embolism should remain a priority in the diagnostic process following a multifactorial risk assessment.

INTERVENTION

The patient was treated with antiplatelet, statin therapy, and foramen ovale closure.

OUTCOME

He recovered well after the interventional closure surgery and is currently under follow-up.

LESSONS

The elderly experiencing a sudden drop in consciousness should be evaluated for thalamic lesions, primarily cerebral infarction in the posterior circulation. Anatomical artery variations may be helpful in attributing multiple and bilateral lesions to a single source of embolism. Digital subtraction angiography and transesophageal echocardiography can help to clarify the etiological categorization and formulate a secondary prevention strategy for cerebral infarction. Paradoxical embolism is a diagnostic dilemma in the elderly population, and treatment principles must be integrated with guidelines, the prospectively validated patent foramen ovale-associated stroke causal likelihood risk stratification system, interdisciplinary collaboration and customized analysis.

Feasibility and safety of cryoballoon ablation for atrial fibrillation and closing patent foramen ovale without implantation: A pilot study

BACKGROUND

Patent foramen ovale (PFO) affects 20%-34% of adults and is associated with strokes and other disorders. The conventional treatment of PFO-related strokes is a closure procedure. The metal device is associated with some adverse events.

OBJECTIVE

Our aim was to investigate the efficacy and safety of PFO closure using cryoablation without implantation in patients with atrial fibrillation (AF) who underwent pulmonary vein isolation (PVI).

METHODS

We divided the 22 patients with both PFO and AF who underwent PVI via cryoablation into 2 groups: standard PVI + atrial septal (AS) cryoablation group (group 1, n = 11) and standard PVI group (group 2, n = 11). The guidewire accesses the left atrium through the PFO without AS puncture during the procedure. Standard PVI via cryoablation was performed. The cryoballoon was retracted to the right atrium and inflated against the AS post-PVI. Patients in group 1 had cryoablation for 120-150 seconds, whereas patients in group 2 received sham ablation. The co-primary end points were the PFO closure rate and a composite of AF recurrence and stroke/transient ischemic attack (TIA) events.

RESULTS

There were no differences in procedure-related adverse events between the 2 groups. Neither group had an ischemic stroke report at 1-year follow-up. The PFO closure rate at 6 months in group 1 was significantly higher than that in group 2 (7 [63.6%] vs 1 [9.1%]; P = .002). AF recurrence post ablation was comparable in both groups at 3 months (3 [27.3%] vs 1 [9.1%]; P = .269), 6 months (0 vs 0), and 12 months (2 [18.2%%] vs 1 [9.1%]; P = .534) of follow-up.

CONCLUSION

Cryoablation is a safe and effective approach to close PFO in patients with AF undergoing PVI in a single procedure.

Interatrial Wall Abnormality is Associated with Adverse Same-Admission Outcomes Following Total Knee Arthroplasty

Total knee arthroplasty (TKA) is the most common joint arthroplasty procedure and is shown to be a reliable and efficacious way to improve quality of life. Individuals with interatrial wall abnormalities (IAWAs), such as atrial septal defect or patent foramen ovale (PFO), are at increased baseline risk for stroke and overall lifetime morbidity. The purpose of our study was to elucidate the association between IAWAs and perioperative TKA outcomes.We performed a retrospective cohort study utilizing the Healthcare Cost and Utilization Project National Inpatient Sample database. Admissions for TKA between 2010 and 2019 were identified using the international classification of disease (ICD)-9 and ICD-10 procedure codes. Patients with ICD-9-clinical modification (CM) diagnosis code 7455 or ICD-10-CM diagnosis code Q211 were assigned to the IAWA cohort, the primary exposure. Confounding variables included basic demographics, baseline health status, and surgical facility characteristics. The primary outcomes studied were medical complications, implant-related complications, and admission mortality. Univariate and adjusted multivariable regression analyses were used to identify associations.Compared to patients in the non-IAWA cohort, those in the IAWA cohort had significant risks for same-admission medical complications (odds ratio [OR] 5.77, 95% confidence interval [CI] 4.59-7.15; p < 0.001), implant-related complications (OR 1.55, 95% CI 1.09-2.12; p = 0.009), stroke (OR 77.46, 95% CI 58.4-101.2; p < 0.001), venous thromboembolism (VTE; OR 3.78 95% CI 2.47-5.51; p < 0.001), and mortality (OR 8.36, 95% CI 3.54-16.52; p < 0.001) following TKA.Compared to patients without IAWAs, those with IAWAs who undergo TKA have higher risks for same-admission medical and implant-related complications as well as same-admission mortality. Similarly, these patients have higher risks for same-admission stroke and VTE. Further research on perioperative TKA management in patients with IAWAs is needed.Level of Evidence is III: retrospective cohort study.

Paradoxical cerebral embolism caused by patent foramen ovale in a patient with multiple endocrine neoplasia type 1 and severe primary hyperparathyroidism

A man in his late 30s with gait difficulty, dysarthria, impaired consciousness and polyuria was diagnosed with left thalamic infarction. Hypercalcaemia (3.52 mmol/L (2.15-2.52)), high intact-parathyroid hormone (i-PTH) levels (88.8 pmol/L (1.1-6.9)) and high D-dimer levels (14.7 mg/L (<1.0)) were identified, followed by a positive microbubble test on transesophageal echocardiogram, suggesting high-risk patent foramen ovale (PFO) for ischaemic stroke. Paradoxical cerebral embolism via PFO, complicated by a hypercoagulable state and hypercalcemic dehydration, was considered. Polyglandular parathyroid hyperplasia, plus radiolucent mandibular tumours, suggested multiple endocrine neoplasia type 1 (MEN1) or hyperparathyroidism-jaw tumour syndrome. Genetic testing confirmed MEN1. Treatment was 24 mg of oral evocalcet and total parathyroidectomy with forearm autotransplantation, resulting in improved serum calcium and i-PTH levels. Finally, he underwent transcatheter PFO closure. We emphasise careful, etiological pursuit in young-onset stroke and the usefulness of genetic testing in differentiating hyperparathyroidism associated with mandibular tumours.

Right Atrial Septal In Situ Microthrombus: A Potential Novel Cause of Patent Foramen Ovale-Associated Stroke

BACKGROUND

Patent foramen ovale (PFO)-associated stroke has a complex and diverse pathogenesis. It mainly results from a paradoxical embolism caused by venous thrombosis. However, few studies have investigated the presence of an in situ thrombus in the right atrium. Transesophageal echocardiography can effectively detect right atrial septal in situ microthrombus. Therefore, we aimed to explore the relationship between a right atrial septal in situ microthrombus and PFO-associated stroke and further dissect the pathophysiological basis of microthrombus formation.

METHODS AND RESULTS

Between April 2022 and October 2023, we prospectively investigated 466 patients who visited our hospital for transesophageal echocardiography with a high clinical suspicion of PFO. Right atrial septal in situ microthrombus was detected in 34 patients (7%), and 23 of them were examined. The microthrombus disappeared in 13 patients and decreased in 7; PFO recanalization and anatomical variations were observed in 2 and 1 patient, respectively. The incidence of index stroke was higher in the microthrombus group than in the nonmicrothrombus group (76.47% versus 61.11%). Univariate and multivariable (adjusted) analyses revealed PFO as an independent risk factor for right atrial septal in situ microthrombus formation (odds ratio, 3.29 [95% CI, 1.49-7.26]; P=0.003).

CONCLUSIONS

Transesophageal echocardiography effectively detects right atrial septal in situ microthrombus. A PFO may promote the formation of right atrial septal in situ microthrombus. Right atrial septal in situ microthrombus significantly increases the risk of PFO-associated stroke. This finding may be crucial in disease management strategies for patients with PFO.

Protrieve Sheath embolic protection during venous thrombectomy: early experience in seventeen patients

PURPOSE

The Protrieve Sheath (Inari Medical; Irvine, CA) is designed for embolic protection during venous thrombectomy. This report describes experience with its use.

MATERIALS AND METHODS

Between November 2022 and December 2023 (13 months), seventeen patients, including nine (52.9%) females and eight (47.1%) males (mean age 58.8 ± 13.3 years, range 37-81 years), underwent deep venous thrombectomy following the Protrieve Sheath placement for embolic protection. Gender, age, presenting symptoms, procedural indications, obstructed venous segments, the Protrieve Sheath access and deployment sites, thrombectomy devices utilized, need for stent reconstruction, technical success, clinical success, adverse events (the Protrieve Sheath maldeployment or clinically significant embolic events), removed thrombi analyses, and mortality were recorded. Technical success was defined as successful deployment of the Protrieve Sheath funnel central to the thrombectomy site. Clinical success was defined as improvement in presenting venous occlusive symptoms without procedure-related venous thromboembolism.

RESULTS

The most common presenting symptom was extremity swelling (n = 15; 88.2%). Nine (52.9%) patients had malignant and eight (47.1%) had benign etiologies of venous obstruction. Obstructed venous segments included the inferior vena cava (IVC) and lower extremity (n = 9; 52.9%), isolated lower extremity (n = 4; 23.5%), isolated IVC (n = 2; 11.8%), thoracic central veins and superior vena cava (n = 1; 5.9%), and isolated thoracic central vein (n = 1; 5.9%). The Protrieve Sheath access sites included the right internal jugular vein (n = 15; 88.2%) for IVC and lower extremity obstructions and the right common femoral vein (n = 2; 11.8%) for thoracic central vein and superior vena cava obstructions. The Protrieve sheath funnel deployment locations included intrahepatic IVC in 13 patients (n = 13; 76.5%), suprarenal IVC in two (n = 2; 11.8%), and inferior cavoatrial junction in two (n = 2; 11.8%). Thrombectomy devices used included the ClotTriever System (Inari Medical) (n = 15; 88.2%), the InThrill Thrombectomy System (Inari Medical) (n = 4; 23.5%), the FlowTriever System (Inari Medical) (n = 2; 11.8%), the Lightning Flash 16 Aspiration System (Penumbra; Salt Lake City, UT) (n = 2; 11.8%), the Cleaner Rotational Thrombectomy System (Argon; Plano, TX) (n = 1; 5.9%), and the RevCore Thrombectomy System (Inari Medical) (n = 1; 5.9%). Ten (58.8%) patients required stent reconstruction following thrombectomy. Technical success was achieved in all patients. Clinical success was achieved in 16 (94.1%) patients. No immediate adverse events, including the Protrieve Sheath maldeployment or clinically significant embolic events, occurred.

CONCLUSION

Use of the Protrieve Sheath during large-bore venous mechanical thrombectomy resulted in favorable technical and clinical outcomes without device-related adverse events or clinically significant thromboembolic events.

Paradoxical cerebral embolism three decades after mustard surgery in a patient with complete transposition of the great arteries: a case report

Atrial switch procedures such as the Mustard operation were previously popular for the complete transposition of the great arteries (i.e. dextro-transposition of the great arteries [d-TGA]). Patients with d-TGA who underwent atrial switch procedures approximately three decades ago have now entered adulthood. A female patient in her 30s with d-TGA had a paradoxical embolic stroke following the initiation of a low-dose oestrogen plus progesterone oral pill for dysmenorrhoea. She underwent Mustard surgery when she was 2 years old. Following a series of procedures including implantation of a permanent pacemaker that was required because of sinus node dysfunction, she had reached adulthood, was living by herself and working independently. One month after taking the low-dose oestrogen plus progesterone oral pill, venous thrombosis occurred in the left soleus and left peroneal veins; and she experienced an acute ischaemic stroke in the right middle cerebral artery area. Transoesophageal echocardiography revealed that the shunt was present only during the Valsalva manoeuvre. Based on the examinations, the patient was diagnosed with juvenile ischaemic stroke as a result of a paradoxical embolism. These findings suggest that paradoxical cerebral embolism can occur as a late complication in patients with d-TGA who underwent the Mustard operation as children.

Prevalence of right-to-left shunt in stroke patients with cancer

BACKGROUND AND OBJECTIVES

Cancer is associated with an increased risk of acute ischemic stroke (AIS) and venous thromboembolism. The role of a cardiac right-to-left shunt (RLS) as a surrogate parameter for paradoxical embolism in cancer-related strokes is uncertain. We sought to investigate the relationship between the presence of an RLS and cancer in AIS patients.

METHODS

We included consecutive AIS patients hospitalized at our tertiary stroke center between January 2015 and December 2020 with available RLS status as detected on transesophageal echocardiography (TEE). Active cancers were retrospectively identified and the association with RLS was assessed with multivariable logistic regression and inverse probability of treatment weighting to minimize the ascertainment bias of having a TEE obtained.

RESULTS

Of the 2236 AIS patients included, 103 (4.6%) had active cancer, of whom 24 (23%) were diagnosed with RLS. An RLS was present in 774 out of the 2133 AIS patients without active cancer (36%). After adjustment and weighting, the absence of RLS was associated with active cancer (adjusted odds ratio (aOR) 2.29; 95% confidence interval (CI), 1.14-4.58). When analysis was restricted to patients younger than 60 years of age or those with a high-risk RLS (Risk of Paradoxical Embolism Score ⩾ 6), there was no association between RLS and cancer (aOR, 3.07; 95% CI, 0.79-11.88 and aOR, 0.56; 95% CI, 0.10-3.10, respectively).

CONCLUSION

RLS was diagnosed less frequently in AIS patients with cancer than in cancer-free patients, suggesting that arterial sources may play a larger role in cancer-related strokes than paradoxical venous embolization. Future studies are needed to validate these findings and evaluate potential therapeutic implications, such as the general indication, or lack thereof, for patent foramen ovale (PFO) closure in this patient population.

Coronary artery thromboembolism as a cause of myocardial infarction with non-obstructive coronary arteries (MINOCA)

Acute myocardial infarction (AMI) usually represents the clinical manifestation of atherothrombotic coronary artery disease (CAD) resulting from atherosclerotic plaque rupture. However, there are cases in which coronary angiography or coronary computed tomography angiography reveals patients with acute coronary syndrome with non-obstructive CAD. This clinical entity is defined as myocardial infarction with non-obstructive coronary arteries (MINOCA) and often considered as a clinical dynamic working diagnosis that needs further investigations for the establishment of a final etiologic diagnosis. The main causes of a MINOCA working diagnosis include atherosclerotic, non-atherosclerotic (vessel-related and non-vessel-related), and thromboembolic causes This literature review aimed to investigate the major thromboembolic causes in patients presenting with MINOCA regarding their etiology and pathophysiologic mechanisms, as well as diagnostic and treatment methods.

Thrombus inside the channel of patent foramen ovale revealed by optical coherence tomography imaging in a patient with myocardial infarction

Background

Myocardial infarction (MI) caused by patent foramen ovale (PFO)-based paradoxical embolism is rare, and there are few case reports in the literature.

Case summary

Here, we report a case of MI in which optical coherence tomography revealed in situ thrombi in the PFO channel.

Discussion

In addition to paradoxical embolism, in situ thrombus may also be one of the pathogenic mechanisms of PFO in patients with MI.

Paradoxical Embolic Stroke Following Percutaneous Transluminal Angioplasty in a Hemodialysis Patient

Paradoxical embolism is a medical condition characterized by the migration of an embolus from a venous source into the systemic circulation. This occurs through a specific cardiac abnormality known as a right-to-left shunt, ultimately resulting in the possibility of arterial embolism. Patent foramen ovale (PFO) is the most common cause of intracardiac shunting. We reported a rare case of a 56-year-old man on hemodialysis with PFO and arteriovenous fistula dysfunction who suffered a paradoxical embolic ischemic stroke after percutaneous transluminal angioplasty. This case emphasized the potential risk of paradoxical embolism in hemodialysis patients with vascular access problems. We aimed to highlight the importance of searching for PFO, as it may serve as a possible source of embolism in these patients.

Low Pneumoperitoneum Pressure Reduces Gas Embolism During Laparoscopic Liver Resection: A Randomized Controlled Trial

OBJECTIVE

To compare the effect of low and standard pneumoperitoneal pressure (PP) on the occurrence of gas embolism during laparoscopic liver resection (LLR).

BACKGROUND

LLR has an increased risk of gas embolism. Although animal studies have shown that low PP reduces the occurrence of gas embolism, clinical evidence is lacking.

METHODS

This parallel, dual-arm, double-blind, randomized controlled trial included 141 patients undergoing elective LLR. Patients were randomized into standard ("S," 15 mm Hg; n = 70) or low ("L," 10 mm Hg; n = 71) PP groups. Severe gas embolism (≥ grade 3, based on the Schmandra microbubble method) was detected using transesophageal echocardiography and recorded as the primary outcome. Intraoperative vital signs and postoperative recovery profiles were also evaluated.

RESULTS

Fewer severe gas embolism cases (n = 29, 40.8% vs n = 47, 67.1%, P = 0.003), fewer abrupt decreases in end-tidal carbon dioxide partial pressure, shorter severe gas embolism duration, less peripheral oxygen saturation reduction, and fewer increases in heart rate and lactate during gas embolization episodes was found in group L than in group S. Moreover, a higher arterial partial pressure of oxygen and peripheral oxygen saturation were observed, and fewer fluids and vasoactive drugs were administered in group L than in group S. In both groups, the distensibility index of the inferior vena cava negatively correlated with central venous pressure throughout LLR, and a comparable quality of recovery was observed.

CONCLUSIONS

Low PP reduced the incidence and duration of severe gas embolism and achieved steadier hemodynamics and vital signs during LLR. Therefore, a low PP strategy can be considered a valuable choice for the future LLR.

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.

PFO-spectrum disorder: two different cerebrovascular diseases in patients with PFO as detected by AI brain imaging software

Background

Patent foramen ovale (PFO) is a prevalent cardiac remnant of fetal anatomy that may pose a risk factor for stroke in some patients, while others can present with asymptomatic white matter (WM) lesions. The current study aimed to test the hypothesis that patients with a PFO who have a history of stroke or transient ischemic attack, compared to those without such a history, have a different burden and distribution of cerebral WM hyperintensities. Additionally, we tested the association between PFO morphological characteristics and severity of shunt, and their impact on the occurrence of ischemic cerebral vascular events and on the burden of cerebral WM lesions.

Patients and methods

Retrospective, case-control study that included patients with PFO confirmed by transesophageal echocardiography. Right-to-left shunt size was assessed using transcranial Doppler ultrasound. Cerebral MRIs were analyzed for all participants using the semi-automated Quantib NDTM software for the objective quantification of WM lesions. WM lesions volume was compared between patients with and without a history of stroke. Additionally, the anatomical characteristics of PFOs were assessed to explore their relation to stroke occurrence and WM lesions volume.

Results

Of the initial 264 patients diagnosed with PFO, 67 met the inclusion criteria and were included in the analysis. Of them, 62% had a history of PFO-related stroke/TIA. Overall burden of WM lesions, including stroke volume, was not significantly different (p = 0.103). However, after excluding stroke volume, WM lesions volume was significantly higher in patients without stroke (0.27 cm3, IQR 0.03-0.60) compared to those with stroke/TIA (0.08 cm3, IQR 0.02-0.18), p = 0.019. Patients with a history of PFO-related stroke/TIA had a tendency to larger PFO sizes by comparison to those without, in terms of length and height, and exhibited greater right-to-left shunt volumes.

Discussion

We suggest that PFO may be associated with the development of two distinct cerebrovascular conditions (stroke and "silent" WM lesions), each characterized by unique imaging patterns. Further studies are needed to identify better the "at-risk" PFOs and gain deeper insights into their clinical implications.

Multiple paradoxical embolisms caused by central venous catheter thrombus passing through a patent foramen ovale: A case report

BACKGROUND

To date, this is the first case of a paradoxical embolism (PDE) that concurrently manifested in the coronary and lower limb arteries and was secondary to a central venous catheter (CVC) thrombus via a patent foramen ovale (PFO).

CASE SUMMARY

Here, we report a case of simultaneous coronary and lower limb artery embolism in a PFO patient carrier of a CVC. The patient presented to the hospital with acute chest pain and lower limb fatigue. Doppler ultrasound showed a large thrombus in the right internal jugular vein, precisely at the tip of the CVC. Transthoracic and transesophageal echocardiography confirmed the existence of a PFO, with inducible right-to-left shunting by the Valsalva maneuver. The patient was administered an extended course of anticoagulation therapy, and then the CVC was successfully removed. Percutaneous PFO closure was not undertaken. There was no recurrence during follow-up.

CONCLUSION

Thus, CVC-associated thrombosis is a potential source for multiple PDE in PFO patients.

Adult Congenital Heart Disease in the Emergency Department

While congenital heart disease historically was a pathology primarily restricted to specialized pediatric centers, advances in technology have dramatically increased the number of people living into adulthood, the number of complications faced by these patients, and the number of patients visiting non-specialized emergency departments for these concerns. Clinicians need to be aware of the issues specific to patients' individual congenital defects but also have an understanding of how typical cardiac pathology may manifest in this special group of patients. This manuscript attempts to provide an overview of this diverse but increasingly common group of adult patients with congenital heart diseases, including a review of their anatomical variants, the complications they face at the highest rates, and ways that emergency physicians may need to manage these patients differently to avoid causing harm.

Kidney Transplant Recipient With Cerebral Paradoxical Embolism Following Recurrent Idiopathic Deep Vein Thrombosis and Pulmonary Embolism: Case Report and Review of the Literature

Paradoxical embolism occurs when a thrombus crosses an intracardiac defect into the systemic circulation. Here, we present the case of a 35-yearold male kidney transplant recipient with a cerebral paradoxical embolism associated with a spontaneous venous thromboembolism. This patient had recurrent deep venous thrombosis and showering emboli to the lung and paradoxically to the brain through patent foramen ovale, and we treated him successfully. The role of bubble echocardiography was essential in diagnosis to avoid contrast-induced nephropathy. This is the first successfully managed case of a kidney transplant recipient with recurrent idiopathic deep vein thrombosis, pulmonary embolism, and cerebral paradoxical embolism. Bubble echocardiography was an excellent alternative to contrast angiography to avoid nephrotoxicity. Vitamin K antagonists are superior to direct oral anticoagulants, especially among nonadherent/noncompliant patients.

Recurrent paradoxical cerebral embolism caused by a thrombus entrapped in a patent foramen ovale: a case report

Introduction

A thrombus straddling the patent foramen ovale (PFO) is a very rare clinical entity. Optimal management remains unclear due to the availability of various therapeutic options; thus, an individualized approach is recommended.

Case presentation

The authors describe a case presenting with recurrent cerebral embolism and a large and mobile thrombus straddled in the PFO. Historically, cardiac surgery, thrombolysis or anticoagulation were possible management options for this patient. However, there are no guidelines on what the optimal treatment is. Our patient was a poor surgical candidate because of advanced age and multiple comorbidities. Furthermore, she had a recent ischaemic stroke which was a relative contraindication to thrombolysis. After consulting the Heart Team, medical treatment alone with systemic anticoagulation was administered. Subsequent transthoracic echocardiography (TTE) after 1 week showed complete thrombus resolution. After 4 months, the PFO was successfully occluded with an Amplatzer device. The patient received rehabilitation therapy and had good functional recovery.

Clinical discussion

Anticoagulant therapy alone was chosen because of high risk for surgery. Complete thrombus resolution was achieved after 1 week although the initial thrombus size was quite large. Nevertheless, this approach may not be applicable to every patient. In addition to TTE, multimodality imaging using transesophageal echocardiography and cardiac magnetic resonance is helpful to identify the mechanism of stroke, which in our case is a thrombus-straddled PFO, and to make early treatment decisions. Serial TTEs help assess the response to anticoagulation. An individualized approach should be made with a multidisciplinary Heart Team.

Conclusion

Echocardiography plays an important role in the diagnosis and treatment evaluation for patients with a thrombus straddling a PFO. An individualized approach to manage the patient should be made with a multidisciplinary Heart Team.

Endovascular approach to a complex thrombus in-transit through a patent foramen ovale

Large atrial thrombi can be managed percutaneously. We present a case of a 76-year-old female patient who presented to our emergency room with an acute stroke and was managed with mechanical thrombectomy. Further work-up revealed a large complex thrombus in-transit trapped in a patent foramen ovale with a large mobile portion in the left atrium. Due to contraindications for thrombolysis and poor surgical candidacy, an endovascular approach was favored. The procedure was performed successfully, and the patient recovered uneventfully.

Learning objective

Endovascular approach with mechanical thrombectomy can be a treatment option for patients that present with large thrombus in-transit when other therapies are contraindicated.

Progressive Memory Decline in a Patient With Atrial Septal Defect: Case Report and Literature Review

Atrial septal defect (ASD) is a common congenital anomaly that increases the risk of heart failure as well as strokes which can lead to cognitive impairment. The risk of stroke is higher when pulmonary hypertension develops and there is reversal of shunt. Stroke in ASD may be due to paradoxical emboli from the right heart or a left ventricular thrombus which develops as a result of atrial fibrillation, a common arrhythmia in ASD. We present a case of a 32-year-old Ghanaian man with history of ASD who presented with progressive memory loss with magnetic resonance imaging scan of the brain showing multiple infarcts, microvascular disease, and cerebral atrophy.

Cerebral Embolic Risk in Coronary and Structural Heart Interventions: Clinical Evidence

Surgical and endovascular procedures for coronary and structural heart interventions carry a meaningful risk of acute stroke with greatly increased likelihood of disability and long-term neurocognitive sequelae. In the last decade, transcatheter aortic valve replacement procedures have focused our attention on a spectrum of procedure-related neurologic injuries that have led to various efforts to prevent ischemic injury with the use of embolic protection devices. As the number of patients undergoing surgical and transcatheter cardiac procedures in the United States continues to increase, the risk of iatrogenic brain injury is concerning, particularly in patient populations already at increased risk of thromboembolism and cognitive decline. In this study, we reviewed the current estimates of the incidence of iatrogenic cerebral embolization and ischemic infarction after surgical and percutaneous transcatheter interventions for coronary artery disease, stenotic aortic and mitral valves, atrial fibrillation, left atrial appendage and patent foramen ovale closure. Our findings show that every year in the United States, nearly 2 million patients undergo coronary and structural heart interventions, with approximately 8000 at risk of experiencing a symptomatic stroke and 330,225 (95% CI, 249,948-430,377) at the risk of ischemic brain injury after the procedure. Given the increased use of surgical and endovascular cardiac procedures in clinical practice, the risk of iatrogenic cerebral embolism is significant and demands careful consideration through neurologic and cognitive assessments and appropriate risk mitigation.

Venous thromboembolism with renal infarct due to paradoxical embolism

Paradoxical thromboembolism has variable presentation depending on site of embolisation. An African-American man in his 40s presented with severe abdominal pain, watery stools and exertional dyspnoea. At presentation, he was tachycardic and hypertensive. Labwork showed elevated creatinine with unknown baseline. Urinalysis showed pyuria. A CT scan was unremarkable. He was admitted with working diagnosis of acute viral gastroenteritis and prerenal acute kidney injury and supportive care was instituted. On day 2, the pain migrated to left flank. Renal artery duplex ruled out renovascular hypertension but showed a lack of distal renal perfusion. MRI confirmed a renal infarct with renal artery thrombosis. Transoesophageal echocardiogram confirmed a patent foramen ovale. Simultaneous arterial and venous thrombosis require hypercoagulable workup, including investigation for malignancy, infection or thrombophilia. Rarely, venous thromboembolism can directly cause arterial thrombosis by 'paradoxical thromboembolism'. Given the rarity of renal infarct, high index of clinical suspicion is necessary.

Case Study of Biatrial Thrombus: Found Down With Atrial Fibrillation

BACKGROUND

Biatrial thrombus is a rare condition that is typically associated with a patent foramen ovale (PFO).

CASE REPORT

This is a case of a 75-year-old man with history of heavy alcohol use found down with altered sensorium. He was hypothermic and in atrial fibrillation with rapid ventricular rate and was subsequently found to have a biatrial thrombus with no evidence of PFO. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Biatrial thrombus presents the unique danger of progressing to both pulmonary embolus and acute embolic disease (including stroke); both are life-threatening diagnoses that can be prevented by means of identifying and treating this rare and dangerous condition.

Pulmonary arteriovenous fistula in a rare location: The importance of excluding patent foramen ovale

A 46-year-old woman with a history of repeated thromboembolic stroke and anti-phospholipid antibody syndrome was referred to our hospital. Saline contrast transthoracic echocardiography showed that microbubbles appeared in the left atrium within 4 heartbeats. Thus, she was initially suspected as having a patent foramen ovale with associated paradoxical embolism. However, no evidence of patent foramen ovale or atrial septal defect could be found using transesophageal echocardiography. Saline contrast transesophageal echocardiography showed that microbubbles flowed into the left atrium through the left superior pulmonary vein. Ultimately, she was diagnosed as having a pulmonary arteriovenous malformation located at the upper left pulmonary lobe using contrast computed tomography and pulmonary artery angiography. Pulmonary arteriovenous malformations are typically located in the lower lobe of either lung and, in bubble studies, contrast appears in the left atrium after 4 heartbeats. Here, the pulmonary arteriovenous malformation was in the upper lobe, and contrast appeared in the left atrium at an earlier time point: one associated with patent foramen ovale. These findings made it difficult to differentiate the two diseases initially. This case suggests that pulmonary arteriovenous malformation should be carefully considered, even if microbubbles appear in the left atrium early on a saline contrast transthoracic echocardiograph.

Learning objective

Pulmonary arteriovenous malformation occasionally appears in the upper lobe. In these cases, microbubbles may appear in the left atrium after detection in the right atrium with a time-course that is suggestive of a patent foramen ovale. Therefore, diagnosis should be carefully confirmed by using other multimodal imaging tests, such as transesophageal echocardiography, contrast computed tomography, or pulmonary artery angiography.

Paradoxical Emboli as a Cause of Stroke

Cerebrovascular embolic strokes are responsible for significant morbidity. 40% of strokes have no inciting cause and are thought to be the result of paradoxical emboli (PDE) passing into the arterial system by way of intra-cardiac or pulmonary vascular defects. We present two cases of PDE resulting in acute ischemic events. A 63-year-old female presented for evaluation of left upper extremity numbness. Imaging was significant for an acute right middle cerebral artery infarct and evidence of a large saddle pulmonary embolism. The patient's stroke was postulated to have been secondary to a patent foramen ovale (PFO). An 87-year-old male presented for evaluation of chest pain. The patient underwent three-vessel CABG and experienced an acute left hemispheric stroke post-operatively. Transthoracic echocardiogram demonstrated a biatrial thrombus transversing a PFO and was postulated to have been the cause. The prompt diagnosis of PDE is paramount to preventing the morbidity associated with repeat ischemic events.

Patent Foramen Ovale Complicated With Renal Infarction and Pulmonary Embolism: A Case Report With Literature Review

A 48-year-old man visited our emergency room after experiencing sudden left back pain, diaphoresis, and nausea. The patient underwent physical and laboratory examinations. Physical examination revealed tenderness in the left costovertebral angle. Laboratory examination revealed a slight elevation in D-dimer levels. Contrast-enhanced computed tomography revealed a bilateral pulmonary embolism and left renal infarction. Back pain was resolved following anticoagulation therapy with heparin. Transesophageal echocardiography revealed a patent foramen ovale (PFO). The patient was discharged on an anticoagulant, apixaban. Identifying the cause of paradoxical embolisms, such as an atrial septal defect or PFO, in cases with an arterial embolism in a young patient with no underlying disease is important.

Correlation between percutaneous patent foramen ovale closure and recurrence of unexplained syncope

Background

The relationship between patent foramen ovale (PFO) and unexplained syncope remains to be illustrated. Therefore, this study aimed to explore the outcomes and prognostic factors for syncope recurrence after PFO closure.

Methods

Patients with both large right-to-left shunting (RLS) PFO and unexplained syncope who visited the cardiovascular department of Xiangya Hospital Central South University from 1 January 2017 to 31 December 2021 were consecutively enrolled in our study. The recurrence rate of syncope was compared between the non-closure group (n = 20) and the closure group (n = 91).

Results

A total of 111 patients were finally included. After 31.11 ± 14.30 months of follow-up, only 11% of patients in the closure group had recurrent syncope, which was much lower than that of the non-closure group (11.0 vs. 35%, P = 0.018). We further investigated the possible prognostic factors for syncope recurrence in the closure group and found syncope occurring more than five times preoperatively, hypertension, and residual RLS at 12-month follow-up were significantly correlated with a higher number of recurrences.

Conclusions

PFO closure reduced the recurrence rate of unexplained syncope. The efficacy of prevention was prognosticated by factors including the presence or absence of syncope induction, the frequency of syncope episodes, and the presence or absence of hypertension. Syncope recurrence was also related to residual shunts post closure.

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.

Myocardial Infarction Due to Paradoxical Thromboembolism Originating From Distal Lower Extremity Deep Vein Thrombosis (LEDVT)

Paradoxical embolism (PDE) originates in the venous system and ends up in the arterial circulation via cardiac or pulmonary shunts. Cases of PDE from venous thrombosis resulting in acute myocardial infarctions (MIs) are seldom reported in the literature. Diagnoses can often be missed if further workups are not pursued in patients without any underlying risk factors for coronary artery disease (CAD). Here, we report a case of a paradoxical embolus that crossed the patent foramen ovale (PFO), causing ST-elevation MI (STEMI) from an embolized venous thrombus originating in the left distal posterior tibial vein.

Embolic myocardial infarction associated with patent foramen ovale: a case series

A patent foramen ovale (PFO) is a fairly common mild cardiac defect that causes a shunting across the atrial septum. PFO is also a known risk factor for cryptogenic stroke. Much less frequently, PFO is associated with non-cerebral systemic embolic events. The article describes a case series of paradoxical embolism of the coronary arteries (CA), which caused myocardial infarction (MI). The presence of PFO was confirmed by imaging techniques. Subsequently, the patients underwent successful endovascular closure of the PFO. Thus, paradoxical CA embolism is a rare and underdiagnosed cause of acute MI. It should be considered in patients with MI and a low risk of atherosclerotic coronary artery disease. However, in most cases, it is not possible to verify the source of the embolism. The significance of occluder implantation as one of the treatment tactics requires further clarification.

Executive Function Poststroke: Concepts, Recovery, and Interventions

Executive function is frequently impaired among people who have sustained stroke. This review provides an overview of definitions, concepts, and measures. The review also summarizes current best evidence examining executive function impairment and recovery trajectories after stroke, correlates of change over time, and emerging intervention research. Finally, this review provides recommendations for research and clinical practices, as well as priorities for future executive function research.

Incidental Thrombus Straddling Patent Foramen Ovale Found on Intraoperative Transesophageal Echocardiogram in a Patient With a Ventricular Assist Device

•

The hemodynamic changes of surgery demand close monitoring in patients with LVADs.

•

During intraoperative TEE, a bubble study may help to diagnose a PFO.

•

TEE monitoring is optimal for patients with LVADs undergoing noncardiac procedures.

Clot Morphology in Acute Ischemic Stroke Decision Making

Stroke is a leading cause of death and disability in the world, and the provision of reperfusion therapy and endovascular therapy, in particular, have revolutionized the treatment of patients with stroke and opened opportunities to look at brain clots retrieved after the procedure. The use of histopathology and molecular profiling of clots is of growing research and clinical interest. However, its clinical implications and incorporation within stroke workflows remain suboptimal. Recent studies have indicated that the study of brain clots may inform the mechanism of stroke and hence guide treatment decision-making in select groups of patients, especially patients without a defined cause or known mechanism. This article provides a comprehensive overview of various clot histopathological examinations in acute stroke-care settings, their clinical utility, and existing gaps and opportunities for further research. We also provide targeted recommendations to improve clot analysis workflow, hence standardizing its incorporation into clinical practice.

Histology of Cerebral Clots in Cryptogenic Stroke Varies According to the Presence of a Patent Foramen Ovale

Although a pathophysiological impact remains difficult to prove in individual patient care, a patent foramen ovale (PFO) is currently considered of high relevance for secondary prophylaxis in selected patients with cryptogenic ischemic stroke. By quantification of histological clot composition, we aimed to enhance pathophysiological understanding of PFO attributable ischemic strokes. Retrospectively, we evaluated all cerebral clots retrieved by mechanical thrombectomy for acute ischemic stroke treatment between 2011 and 2021 at our comprehensive stroke care center. Inclusion criteria applied were cryptogenic stroke, age (≤60 years), and PFO status according to transesophageal echocardiography, resulting in a study population of 58 patients. Relative clot composition was calculated using orbit image analysis to define the ratio of main histologic components (fibrin/platelets (F/P), red blood cell count (RBC), leukocytes). Cryptogenic stroke patients with PFO (PFO+, n = 20) displayed a significantly higher percentage of RBC (0.57 ± 0.17; p = 0.002) and lower percentage of F/P (0.38 ± 0.15; p = 0.003) compared to patients without PFO (PFO–, n = 38) (RBC: 0.41 ± 0.21; F/P: 0.52 ± 0.20). In conclusion, histologic clot composition in cryptogenic stroke varies depending on the presence of a PFO. Our findings histologically support the concept that a PFO may be of pathophysiological relevance in cryptogenic ischemic stroke.

Right-to-Left Shunts Occur During Cardiopulmonary Resuscitation: Echocardiographic Observations

OBJECTIVES

A significant proportion of the population has a patent foramen ovale (PFO). The intracardiac pressure during cardiopulmonary resuscitation (CPR) may differ from that of normal circulation, which may result in a right-to-left shunt in the presence of a PFO. In this study, transesophageal echocardiography (TEE) was conducted to evaluate whether CPR carried out in patients after cardiac arrest causes right-to-left shunt.

DESIGN

A retrospective observational study.

SETTING

One academic medical center from January 2017 to April 2020.

PATIENTS

Patients older than 20 years who suffered from nontraumatic out-of-hospital cardiac arrest (OHCA) and underwent intra-arrest TEE.

MEASUREMENT AND MAIN RESULTS

Patients who had microbubbles resulting from fluid injection in the right atrium, as indicated on TEE imaging, were included in the analysis. The presence of right-to-left shunt was defined as the appearance of microbubbles in the systemic circulation, including the left atrium, left ventricle, or aorta. A total of 97 patients were included in the final analysis. A right-to-left shunt was observed in 21 patients (21.6%), and no shunt was found in 76 patients (78.4%). The degree of the right-to-left shunt, determined by the number of microbubbles, was mild in 11 patients (52.4%), moderate in eight (38.0%), and severe in two (9.6%). Multivariate analysis showed that no factors were associated with the presence of right-to-left shunt during CPR.

CONCLUSIONS

Right-to-left shunts can be appreciated during CPR in patients who experience OHCA. Further studies are needed to verify its clinical significance.

Carbon Dioxide Embolism During Transanal Total Mesorectal Excision: Case Report and Literature Review

The actual incidence of carbon dioxide embolism during transanal total mesorectal excision (taTME) is unknown, but the reported incidence in the existing literature is reassuring. However, the incidence of CO2 embolism, which can be life-threatening, is severely underestimated. By reviewing the available data on carbon dioxide embolism during taTME and synthesizing other reports on CO2 embolism in laparoscopic procedures, we provide the first comprehensive account of the etiology, pathophysiology, and recommend tools to monitor carbon dioxide embolism during taTME. Additionally, we provide guidance and recommendations on preventive and therapeutic measures to minimize the adverse consequences of this potentially severe complication, knowledge about which we hope will improve patients' safety.

T-wave Inversions in Cerebellar and Occipital Lobe Infarcts in the Setting of Deep Vein Thrombosis and Pulmonary Embolism Suggestive of Paradoxical Emboli: A Case Report

Cardiological causes account for the majority of acute electrocardiographic (ECG) changes. The reason for this fear is the irreversibility of myocardial necrosis. Generally, various changes can be observed in the ECG, including ST-T changes, QTc prolongation, arrhythmias, and T-wave inversions. Even though T-wave inversions can be seen in myocardial ischemia/infarction, they are rarely seen in acute cerebrovascular accidents (CVAs). We present the case of a 66-year-old woman who initially presented at our facility with dizziness in the context of orthostatic hypotension. An initial cardiac evaluation revealed no cardiac involvement. She was treated with intravenous fluids (IVF), which improved her symptoms. The patient's mental status was markedly altered approximately four days after admission. In this instance, she was found to have abnormal ECG findings (not previously observed on the ECG that was obtained on the day of admission), elevated troponin T levels, as well as elevated pro-B-type natriuretic peptide (pro-BNP). The patient was given aspirin and clopidogrel immediately and was placed on a heparin drip for a suspected non-ST elevation myocardial infarction (NSTEMI). A non-contrast computed tomography of the head revealed an acute cerebrovascular accident (CVA), following which the heparin drip was stopped. The patient was then transferred to another acute care facility capable of performing neurosurgical interventions. Additionally, a computed tomography angiography (CTA) of the chest and lower extremities venous duplex showed bilateral pulmonary emboli and deep venous thrombosis (DVT), respectively.