Left Atrial Dysfunction in Patients With Patent Foramen Ovale and Atrial Septal Aneurysm

Overview and Future Direction of Embolic Stroke of Undetermined Source from the Insights of CHALLENGE ESUS/CS Registry

Cryptogenic stroke (CS) accounts for approximately one-fourth of acute ischemic strokes, with most cases derived from embolic etiologies. In 2014, embolic stroke of undetermined source (ESUS) was advocated and the efficacy of anticoagulant therapy was anticipated. However, 3 large-scale clinical trials failed to demonstrate the superiority of direct oral anticoagulants (DOACs) over aspirin, potentially due to the heterogeneous and diverse pathologies of ESUS, including paroxysmal atrial fibrillation (AF), arteriogenic sources such as nonstenotic carotid plaque and aortic complicated lesion (ACL), patent foramen oval (PFO), and nonbacterial thrombotic endocarditis (NBTE) related to active cancer.Transesophageal echocardiography (TEE) is one of the most effective imaging modalities for assessing embolic sources in ESUS and CS. The Mechanisms of Embolic Stroke Clarified by Transesophageal Echocardiography for Embolic Stroke of Undetermined Source/Cryptogenic Stroke (CHALLENGE ESUS/CS) registry is a multicenter registry that enrolled consecutive patients with CS who underwent TEE at 8 hospitals in Japan between April 2014 and December 2016. Their mean age was 68.7±12.8 years, and 455 patients (67.2%) were male. The median National Institutes of Health Stroke Scale (NIHSS) score was 2. Since 7 analyses have been conducted from each institution to date, novel and significant insights regarding embolic origins and pathophysiologies of ESUS and CS were elucidated from this multicenter registry. This review discusses the diagnosis and treatment of ESUS and CS, tracing their past and future directions. Meaningful insights from the CHALLENGE ESUS/CS registry are also referenced and analyzed.

Comparison of the Application Value of Transthoracic Echocardiography in Diagnosing Patent Foramen Ovale Under Different States of Stimulation: A Retrospective Study

OBJECTIVE

This study aims to evaluate the application value of contrast-enhanced transthoracic echocardiography (cTEE) in the diagnosis of patent foramen ovale (PFO) under different states of stimulation, with the goal of enhancing the accuracy and efficiency of PFO diagnosis.

METHODS

This research consecutively enrolled patients suspected of having PFO from October 2022 to February 2024, presenting primary clinical symptoms such as unexplained syncope, headache, dizziness, and stroke. Patients underwent standard transthoracic echocardiography (TTE) and cTEE under three different states of stimulation (resting state, coughing, and Valsalva maneuver). Based on the presence of microbubbles in the left heart and their initial appearance time, patients were classified into PFO and control groups, with further diagnostic confirmation via transesophageal echocardiography (TEE) or foramen ovale closure procedures.

RESULTS

The study results revealed significant differences between the PFO and control groups regarding age (p = 0.034) and headache symptoms (p = 0.001). In the PFO group, TTE showed a higher positivity rate both at rest and during coughing, highlighting the association between PFO and specific clinical symptoms. The number of microbubbles observed during TTE increased significantly under various stimulation states, particularly during the Valsalva maneuver (p < 0.05). This increase became more pronounced as the duration of the maneuver was extended, underscoring the differential response of PFO patients under varied physiological testing conditions, especially during prolonged Valsalva maneuvers.

CONCLUSION

The study confirms the significant value of cTEE in diagnosing PFO under different stimulation states, particularly emphasizing the application of the Valsalva maneuver to significantly improve the sensitivity and specificity of PFO detection. Thus, incorporating cTEE examinations under various stimulation states holds significant clinical importance for enhancing the accuracy and efficiency of PFO diagnosis.

Congenital heart disease: types, pathophysiology, diagnosis, and treatment options

Congenital heart disease (CHD) is a structural abnormality of the heart and/or great vessels and patients with CHD are at an increased risks of various morbidities throughout their lives and reduced long-term survival. Eventually, CHD may result in various complications including heart failure, arrhythmias, stroke, pneumonia, and sudden death. Unfortunately, the exact etiology and pathophysiology of some CHD remain unclear. Although the quality of life and prognosis of patients with CHD have significantly improved following technological advancement, the influence of CHD is lifelong, especially in patients with complicated CHD. Thus, the management of CHD remains a challenge due to its high prevalence. Finally, there are some disagreements on CHD among international guidelines. In this review, we provide an update of the pathophysiology, diagnosis, and treatment in most common type of CHD, including patent foramen ovale, atrial septal defect, ventricular septal defect, atrioventricular septal defect, patent ductus arteriosus, coarctation of the aorta, transposition of the great arteries, congenitally corrected transposition of the great arteries, coronary anomalies, left and right ventricular outflow tract obstruction, tetralogy of Fallot and Ebstein anomaly. In particular, we focus on what is known and what is unknown in these areas, aiming to improve the current understanding of various types of CHD.

Does Atrial Septal Anatomy Still Matter in the Etiological Evaluation of Ischemic Stroke Beyond the Age of 60?

BACKGROUND

Patent foramen ovale (PFO) is causally associated with stroke in some patients younger than 60 years, especially when it is large or associated with an atrial septal aneurysm (ASA). After 60 years of age, this association is less well understood. We assessed the relationships between detailed atrial septal anatomy and the cryptogenic nature of stroke in this population.

METHODS AND RESULTS

We reviewed all patients aged 60 to 80 years admitted to our stroke center for ischemic stroke who underwent contrast echocardiography between 2016 and 2021. The atherosclerosis, small-vessel disease, cardiac pathology, other causes, and dissection (ASCOD) classification was used to reevaluate the etiological workup. Associations between cryptogenic stroke and (1) PFO presence or (2) categories of PFO anatomy (nonlarge PFO without ASA, nonlarge PFO with ASA, large PFO without ASA, and large PFO with ASA) were assessed using logistic regression. Among 533 patients (median National Institutes of Health Stroke Scale score=1), PFO was present in 152 (prevalence, 28.5% [95% CI, 24.9-32.5]). Compared with noncryptogenic stroke, cryptogenic stroke (n=218) was associated with PFO presence (44.5% versus 17.5%; P<0.0001). Among patients with a PFO, septal anatomy categories were associated with cryptogenic stroke (P=0.02), with a strong association for patients with both large PFO and ASA (38.1% versus 14.5%, P=0.002).

CONCLUSIONS

PFO presence remains strongly associated with cryptogenic stroke between 60 and 80 years of age. Large PFO, ASA, and their association were strongly associated with cryptogenic stroke in this age group. Our results support performing contrast echocardiography even after 60 years of age, although the optimal secondary prevention therapy in this population remains to be determined in randomized trials.

A Patent Foramen Ovale With an Atrial Septal Aneurysm in a Patient Presenting With Deep Vein Thrombosis and Pulmonary Embolism

Patent foramen ovale (PFO) is an embryogenic remnant that can be found in healthy adults with no repercussions. However, it poses a risk of paradoxical embolism. In patients with known embolic stroke, the risk of recurrence is greater. A PFO can be accompanied by morphological variants such as atrial septal aneurysms (ASA). These have been shown to further increase the risk of stroke and embolism. This is a case of a patient who presented to the emergency department with deep vein thrombosis and sub-massive pulmonary embolism. An echocardiogram showed a PFO with an ASA as an incidental finding. The defect was closed with a transcatheter PFO closure device due to a high risk of paradoxical embolism.

Patent Foramen Ovale Management for Secondary Stroke Prevention: State-of-the-Art Appraisal of Current Evidence

Patent foramen ovale (PFO) is frequently identified in young patients with ischemic stroke. Randomized controlled trials provide robust evidence supporting PFO closure in selected patients with cryptogenic ischemic stroke; however, several questions remain unanswered. This report summarizes current knowledge on the epidemiology of PFO-associated stroke, the role of PFO as a cause of stroke, and anatomic high-risk features. We also comment on breakthrough developments in patient selection algorithms for PFO closure in relation to the PFO-associated stroke causal likelihood risk stratification system. We further highlight areas for future research in PFO-associated stroke including the efficacy and safety of PFO closure in the elderly population, incidence, and long-term consequences of atrial fibrillation post-PFO closure, generalizability of the results of clinical trials in the real world, and the need for assessing the effect of neurocardiology teams on adherence to international recommendations. Other important knowledge gaps such as sex, race/ethnicity, and regional disparities in access to diagnostic technologies, PFO closure devices, and clinical outcomes in the real world are also discussed as priority research topics.

Atrial septal aneurysm contribution to the risk of cryptogenic stroke in patients with patent foramen ovale: A brief updated systematic review and meta-analysis

Atrial septal aneurysms (ASA) play an important role in cryptogenic stroke (CS) in patients with patent foramen ovale (PFO) but its contribution remains still not fully clarified in current literature. We sought to evaluate the contribution of ASA to the risk of CS in PFO patients based on studies published so far by means of a systematic review and metanalysis. A literature search, based on PubMed, Google Scholar and EMBASE databases, was performed to locate articles, published English language between 2000 and 2021, analysing the relationship between ASA and CS. The final research was conducted in September 2021. A total of 577 articles were retrieved after excluding duplicates. The initial screening excluded 215 articles because they did not meet inclusion criteria, leaving 362 articles to assess for eligibility. Subsequently, after evaluation of the full-text articles, 354 were excluded and 8 investigations met the inclusion criteria. Overall, 822 patients (mean age 48.3 years) were enrolled in the reviewed manuscripts with a prevalence of males of 48.7% and a normal distribution of the classical cardiovascular risk factors. ASA was present in 25.3% (208 subjects) of the patients enrolled, while the association of PFO+ASA was observed in 24.3% (200 subjects) of patients enrolled. PFO Patients with ASA were at higher risk of CS compared to those without (odd ratio: 3.38, 95% CI: 2.72-5.51, p<0.001, I2=4.3%,). The relative funnel plot did not show any evident asymmetry, confirming absence of publication bias. Our updated metanalysis enhances the importance of ASA contribution to stroke in patients with patent foramen ovale, being present in a third of patients with symptomatic PFO to whom it confers an additional odd ratio of 3.38.

Association of Atrial Septal Aneurysm and Shunt Size With Stroke Recurrence and Benefit From Patent Foramen Ovale Closure

Importance

The Patent Foramen Ovale (PFO)-Associated Stroke Causal Likelihood classification system combines information regarding noncardiac patient features (vascular risk factors, infarct topography) and PFO features (shunt size and presence of atrial septal aneurysm [ASA]) to classify patients into 3 validated categories of responsiveness to treatment with PFO closure. However, the distinctive associations of shunt size and ASA, alone and in combination, have not been completely delineated.

Objective

To evaluate the association of PFO closure with stroke recurrence according to shunt size and/or the presence of an ASA.

Design, Setting, and Participants

Pooled individual patient data from 6 randomized clinical trials conducted from February 2000 to October 2017 that compared PFO closure with medical therapy. Patients in North America, Europe, Australia, Brazil, and South Korea with PFO-associated stroke were included. Analysis was completed in January 2022.

Exposures

Transcatheter PFO closure plus antithrombotic therapy vs antithrombotic therapy alone, stratified into 4 groups based on the combination of 2 features: small vs large PFO shunt size and the presence or absence of an ASA.

Main Outcomes and Measures

Recurrent ischemic stroke.

Results

A total of 121 recurrent ischemic strokes occurred in the pooled 3740 patients (mean [SD] age, 45 [10] years; 1682 [45%] female) during a median (IQR) follow-up of 57 (23.7-63.8) months. Treatment with PFO closure was associated with reduced risk for recurrent ischemic stroke (adjusted hazard ratio [aHR], 0.41 [95% CI, 0.28-0.60]; P < .001). The reduction in hazard for recurrent stroke was greater for patients with both a large shunt and an ASA (aHR, 0.15 [95% CI, 0.06-0.35]) than for large shunt without ASA (aHR, 0.27 [95% CI, 0.14-0.56]), small shunt with ASA (aHR, 0.36 [95% CI, 0.17-0.78]), and small shunt without ASA (aHR, 0.68 [95% CI, 0.41-1.13]) (interaction P = .02). At 2 years, the absolute risk reduction of recurrent stroke was greater (5.5% [95% CI, 2.7-8.3]) in patients with large shunt and ASA than for patients in the other 3 categories (1.0% for all).

Conclusions and Relevance

Patients with both a large shunt and an ASA showed a substantially greater beneficial association with PFO closure than patients with large shunt alone, patients with small shunt and ASA, and patients with neither large shunt nor ASA. These findings, combined with other patient features, may inform shared patient-clinician decision-making.

Increased Blood Residence Time as Markers of High-Risk Patent Foramen Ovale

Previous investigations have suggested that patients with patent foramen ovale (PFO) often have an atrial dysfunction, like to that observed in patients with atrial fibrillation (AF) which may concur to an increased risk of cryptogenic stroke. The aim of the study is to compare the atrial resident time (Rt) of PFO patients to those with sinus rhythm (SR) and AF using patient-specific 3D computational fluid dynamics (CFD) analysis. Models of left atrium (LA) hemodynamics were obtained from time-resolved CT scans and transthoracic echocardiography (TTE). Enrolled patients were divided into three groups: 30 healthy subjects with SR, 30 with PFO, and 30 with AF without PFO. Blood stasis was evaluated by determining the blood residence time (Rt) distribution in the LA and left atrial appendage (LAA). Overall, 90 patients (mean age 47.4 ± 7.5 years, 51 males) were included into the analysis. PFO patients exhibit higher mean Rt values compared to healthy subjects (2.65 ± 0.2 vs 1.5 ± 0.2 s). Conversely, AF patients presented higher Rt when compared to PFO patients (2.9 ± 0.3 vs 2.3 ± 0.2 s). Moreover, PFO patients presenting cerebral lesions at magnetic resonance imaging have a higher Rt compared to those without (2.9 ± 0.3 vs 2.3 ± 0.2 s, respectively, p < 0.001). PFO patients have a higher degree of atrial Rt compared to healthy subjects similar to that observed in AF patients. The higher mean LA Rt values offer an insight into the pathophysiological mechanism linking PFO with cryptogenic stroke and might be a marker of high-risk PFOs.

Advances in the management of cardioembolic stroke associated with patent foramen ovale

Patent foramen ovale (PFO) describes a valve in the interatrial septum that permits shunting of blood or thrombotic material between the atria. PFOs are present in approximately 25% of the healthy population and are not associated with any pathology in the vast majority of cases. However, comparisons between patients with stroke and healthy controls suggest that PFOs may be causative of stroke in certain patients whose stroke is otherwise cryptogenic. Options for the diagnosis of PFO include transthoracic echocardiography, transesophageal echocardiography, and transcranial Doppler ultrasonography. PFOs associated with an interatrial septal aneurysm seem to be more strongly linked to risk of recurrent stroke. Therapeutic options for secondary stroke prevention in the setting of a PFO include antiplatelet therapy, anticoagulation, and percutaneous device closure. Recent randomized clinical trials suggest that percutaneous closure reduces the subsequent risk of stroke in appropriately selected patients, with a large relative benefit but small absolute benefit. Referral for percutaneous PFO closure should therefore be considered in certain patients after a multidisciplinary, patient centered discussion. Areas for future study include structural biomarkers to aid in determining the role of PFO closure in older people with possible PFO associated stroke, the role of direct oral anticoagulants, and very long term outcomes after device closure.

Patent foramen ovale closure review: decades of research and the evolution of the evidence

Background

A quarter of the population suffers from patent foramen ovale, a form of interatrial shunt. It has been linked to cryptogenic strokes and is a common cause of paradoxical embolism.

Main text

The benefit of closing the patent foramen ovale in cryptogenic stroke patients aged 18-60 years to prevent recurrent strokes, particularly in those with large shunts or associated atrial septal aneurysms, was recently demonstrated. It is a relatively safe procedure that necessitates post-operative anticoagulation, but it has been linked to new-onset atrial fibrillation of uncertain significance. The effectiveness of patent foramen closure depends on patient selection, and prediction scores such as the Risk of Paradoxical Embolism (RoPE) score should be used. Newer closure devices, such as bioabsorbable devices like the Biostar system and ‘device-less’ devices like the Noble Stitch, are becoming more common due to their lower operative risks. The use of such devices in future trials, as well as careful case selection, could improve the acceptability of patent foramen ovale closure in the general population, removing the need for perioperative anticoagulation.

Conclusion

Individuals aged 18-60 years with cryptogenic stroke who have adverse patent foramen ovale morphology on imaging should be offered patent foramen ovale closure, preferably using the newer closure devices. More studies are needed to determine the significance of periprocedural atrial fibrillation after device closure.

Atrial Septal Aneurysms - A Clinically Relevant Enigma?

Atrial septal aneurysms (ASAs) are often seen during routine cardiac imaging, though their clinical relevance has been poorly defined. The aneurysmal, and often mobile, inter-atrial septum is frequently associated with other clinically relevant structural cardiac abnormalities, particularly patent foramen ovale (PFO). Whilst ASAs have previously been considered an incidental finding, a well-endowed atrial septum provides more than visual interest, including insights into atrial function and intra-atrial pressures, and has important clinical implications in PFO-associated stroke, migraines, and arrhythmias. This review outlines diagnostic challenges when assessing ASAs using all imaging modalities and the clinical implications of this common anatomical variant.

A meta-analysis of the association of atrial septal abnormalities and atrial vulnerability

BACKGROUND

The mechanism of cryptogenic stroke (CS) in patients with atrial septal abnormalities remains unclear, and the increased incidence of atrial vulnerability may be one of the reasons. We performed this meta-analysis to clarify the association between atrial septal abnormalities and atrial vulnerability, and to provide evidence-based basis for the prevention and mechanism of CS.

METHODS

We systematically searched for studies on the association between atrial septal abnormalities and atrial vulnerability, and pooled available data on types of atrial septal abnormalities, types of atrial vulnerability, and methods of atrial vulnerability detection. The primary endpoints were the occurrence of atrial arrhythmias or P wave abnormalities. Random-effects models were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Twelve case-control studies were eligible. Compared with the control group, patients with atrial septal abnormalities had a higher risk of atrial vulnerability (OR: 1.93; 95% CI: 1.13-3.30, P = .02). Data based on stroke patients showed that the group with atrial septal abnormalities had a higher risk of atrial vulnerability than the control group (OR: 2.00; 95% CI: 1.13-3.53, P = .02). However, there was no significant difference in the incidence of atrial vulnerability between the 2 groups of nonstroke patients. Subgroup analysis showed that although atrial septal abnormality increased the risk of atrial vulnerability in the subgroup of atrial septal aneurysm (OR: 1.68; 95% CI: 0.47-5.95, P = .42), the subgroup of atrial fibrillation (AF)/atrial fluster (OR: 1.81; 95% CI: 0.94-3.46, P = .07) and the subgroup of subcutaneous recording system (OR: 1.33; 95% CI: 0.68-2.61, P = .41), the difference was not statistically significant.

CONCLUSIONS

Atrial septal abnormalities can increase the risk of atrial vulnerability, and atrial arrhythmia caused by atrial septal abnormalities may be one of the mechanisms of CS.

Persistent pathology of the patent foramen ovale: a review of the literature

A patent foramen ovale (PFO) is an interatrial shunt, with a prevalence of 20-34% in the general population. While most people do not have secondary manifestations of a PFO, some reported sequelae include ischaemic stroke, migraine, platypnoea-orthodeoxia syndrome and decompression illness. Furthermore, in some cases, PFO closure should be considered for patients before neurosurgery and for patients with concomitant carcinoid syndrome. Recent trials support PFO closure for ischaemic stroke patients with high risk PFOs and absence of other identified stroke mechanisms. While PFOs can be associated with migraine with auras, with some patients reporting symptomatic improvement after closure, the evidence from randomised controlled trials is less clear in supporting the use of PFO closure for migraine treatment. PFO closure for other indications such as platypnoea-orthodeoxia syndrome, decompression illness and paradoxical embolism are based largely on case series with good clinical outcomes. PFO closure can be performed as a day surgical intervention with high procedural success and low risk of complications.

Right atrium and cryptogenic ischaemic stroke in the young: a case-control study

Background

Recent studies suggest left atrial (LA) dysfunction in cryptogenic stroke. We studied the dynamics of right atrium (RA) and right atrial appendage (RAA) in young adults with cryptogenic stroke. We hypothesised that bi-atrial dysfunction and blood stagnation might contribute to thrombosis formation in patients with patent foramen ovale (PFO), as deep venous thrombosis is detected only in the minority of patients.

Methods

Thirty patients (aged 18–49) with a first-ever cryptogenic stroke and 30 age-matched and sex-matched stroke-free controls underwent cardiac magnetic resonance (CMR) imaging. An approach to estimate the RAA volume was developed, using crista terminalis and pectinate muscles as anatomical landmarks. Atrial expansion indices were calculated as (maximal volume – minimal volume) ×100%/minimal volume. Total pulmonary to systemic blood flow ratio (Qp/Qs) was based on phase contrast CMR. Right-to-left shunt (RLS) was evaluated with transoesophageal echocardiography in 29 patients and transcranial Doppler in 30 controls, moderate-to-severe RLS considered as clinically significant.

Results

We found that RA and RAA volumes were similar between patients and controls. Also, RA expansion index was similar, but RAA (95.6%±21.6% vs 108.7%±25.8%, p=0.026) and LA (126.2%±28% vs 144.9%±36.3%, p=0.023) expansion indices were lower in patients compared with controls. Seven (24%) of 29 patients had an RLS compared with 1 (3%) of 30 controls (p=0.012). Among 59 study subjects, RLS was associated with lower RA (81.9%±15.9% vs 98.5%±29.5%, p=0.030), RAA (84.7%±18% vs 105.6%±24.1%, p=0.022), LA (109.8%±18.6% vs 140.1%±33.7%, p=0.017) and LAA (median 102.9% (IQR 65.6%–121.7%) vs 229.1% (151.8%–337.5%], p=0.002) expansion indices and lower Qp/Qs ratio (0.91±0.06 vs 0.98±0.07, p=0.027).

Conclusions

This study suggests bi-atrial dysfunction in young adults with cryptogenic stroke, associated with moderate-to-severe RLS. Dysfunction of the atria and atrial appendages may be an additional mechanism for PFO-related stroke.

Trial registration number

NCT01934725.

Atrial Septal Aneurysm may Cause In-Hospital Recurrence of Cryptogenic Stroke

AIMS

Awareness of potentially embologenic diseases is critical to determining the prognosis of cryptogenic stroke. The clinical significance of atrial septal aneurysm (ASA) in cryptogenic stroke has not been fully studied. Therefore, we explored clinical characteristics and in-hospital recurrence in patients with ASA in cryptogenic stroke.

METHODS

A multicenter observational registry of cryptogenic stroke patients was conducted. We obtained baseline characteristics, radiological and laboratory findings, and echocardiographic findings, especially of embolic sources on transesophageal echocardiography. The CHALLENGE ESUS/CS (Mechanisms of Embolic Stroke Clarified by Transesophageal Echocardiography for embolic stroke of undetermined source/cryptogenic stroke) registry was recorded at http://www.umin.ac.jp/ctr/ (UMIN000032957). Patients' clinical characteristics were compared according to the presence of ASA, and factors associated with in-hospital stroke recurrence were assessed.

RESULTS

The study included 671 patients (age, 68.7±12.7 years; 450 males; median National Institutes of Health Stroke Scale score, 2). ASA was detected in 92 patients (14%), displaying higher age (72.4±11.0 vs. 68.1 ±12.9 years, p=0.004), reduced frequency of diabetes mellitus (16% vs. 27%, p=0.030), higher frequency of right-to-left shunt (66% vs. 45%, p＜0.001), and in-hospital stroke recurrence (8% vs. 3%, p=0.034). ASA was relatively associated with in-hospital recurrence (odds ratio 2.497, 95% confidence interval 0.959-6.500, p= 0.061).

CONCLUSIONS

The CHALLENGE ESUS/CS registry indicated that ASA was not rare in cryptogenic stroke, and ASA's clinical characteristics included higher age, reduced frequency of diabetes mellitus, and increased frequency of concomitant right-to-left shunt. ASA may be related to in-hospital stroke recurrence in cryptogenic stroke.

The evolving role of echocardiography in the assessment of patent foramen ovale in patients with left-side thromboembolism

Patent foramen ovale (PFO) is the most common congenital cardiac abnormality found approximately in 25% of the adult population The pathophysiological role of paradoxical embolization through the PFO in ischemic stroke is well established. "Self-expanding double disk" and, more recently, suture-based "deviceless" systems are used for PFO closure in the setting of secondary prevention after ischemic stroke likely related to paradoxical embolization. Ultrasound plays a significant role in PFO assessment, indication to treatment, intra-procedural guidance, and follow-up for those undergoing PFO closure. Three different techniques are frequently used for these purposes: transesophageal echocardiography, transthoracic echocardiogram, and transcranial Doppler. In this review, advantages and limits of these techniques are discussed in detail to improve our skills in detection and treatment of this important condition by using ultrasound.

Left Atrial Function in Young Patients With Cryptogenic Stroke and Patent Foramen Ovale: A Left Atrial Longitudinal Strain Study

Background: The study of left atrial (LA) longitudinal strain by speckle tracking is a reliable method for analyzing LA function that could provide relevant information in young patients with cryptogenic stroke (CS). The aim of this study was to investigate whether the presence of a patent foramen ovale (PFO) impacts the LA longitudinal strain in a population of young patients with first CS.

Methods and Results: Patients aged 18 to 54 years, treated consecutively in a university hospital for first CS, were included in this study. The presence of a PFO and an atrial septal aneurysm (ASA) was investigated using transesophageal echocardiography and transcranial Doppler. Speckle tracking analysis was performed on transthoracic echocardiography, allowing the measurement of global, passive, and active longitudinal LA strain, corresponding to the reservoir, conduit, and contractile function, respectively. A total of 51 patients were included in the study. In a multivariable analysis, overweight was associated with reduced global and passive LA longitudinal strain (P = 0.013 and P = 0.018, respectively), and hypertension was associated with reduced active LA longitudinal strain (P = 0.049). LA longitudinal strain was not different between patients with PFO or PFO plus ASA and patients without PFO.

Conclusion: LA longitudinal strain in young subjects with CS was impaired in the presence of overweight and hypertension, but not of PFO or PFO plus ASA.

Patent Foramen Ovale in Cryptogenic Ischemic Stroke: Direct Cause, Risk Factor, or Incidental Finding?

Patent foramen ovale (PFO) has been associated with cryptogenic stroke. There is conflicting data and it remains uncertain whether PFO is the direct cause, a risk factor or an incidental finding. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signaling disruption. Main risk factors linked with PFO-attributable strokes are young age, PFO size, right-to-left shunt degree, PFO morphology, presence of atrial septal aneurysm, intrinsic coagulation-anticoagulation systems imbalance, and co-existence of other atrial abnormalities, such as right atrial septal pouch, Eustachian valve and Chiari's network. These may act independently or synergistically, multiplying the risk of embolic events. The RoPE score, a scale that includes factors such as young age, cortical infarct location and absence of traditional stroke risk factors, is associated with the probability of a PFO being pathogenic and stroke recurrence risk after the index stroke. Multiple investigators have attempted to correlate other PFO features with the risk of PFO-related stroke, but further investigation is needed before any robust conclusions are reached. PFO presence in young patients with cryptogenic stroke should be considered as etiologically suspect. Caution should be exercised in interpreting the relevance of other PFO features.

Atrial septal aneurysm in pregnancy: echocardiography and obstetric outcomes

Background Atrial septal aneurysm (ASA) is an uncommon cardiac anomaly that increases maternal morbidity during pregnancy. ASA is related to atrial arrhythmia thromboembolism and it may accompany congenital anomalies such as an atrial septal defect (ASD) or patent foramen ovale (PFO). There are no studies examining pregnancy outcomes in pregnant women with ASA. We aimed to investigate the cardiologic parameters and obstetric outcomes of pregnant women diagnosed with ASA. Methods This prospective cohort study analyzed 45 pregnant women diagnosed with ASA, who continued their follow-ups in an obstetric tertiary care center. Results A total of 45 pregnant women were recruited; seven pregnancies ended before the 20th gestational week (six spontaneous abortion, one fetal anomaly), 38 women gave birth. In total, there were 32 term births (≥37 weeks), six preterm births (<37 weeks), two extremely preterm births <28 weeks). Among 38 babies delivered, several obstetrical complications such as oligohydramnios, spontaneous preterm labor, intrauterine growth restriction (IUGR), preeclampsia and gestational diabetes mellitus (GDM) developed in 16 patients, while 22 women ended with term pregnancy without any complications. Deep venous thrombosis (DVT) developed in one patient. Conclusion ASA may have an increased risk for cardiac complications during pregnancy and may also be associated with poor pregnancy outcomes. Increased attention to these entities with more studies is needed in order to determine a potential risk for pregnant women.

Patent Foramen Ovale, the Role of Antiplatelet Therapy Alone or Anticoagulant Therapy Alone Versus Device Closure for Cryptogenic Stroke: A Review of the Literature and Current Recommendations

Cryptogenic stroke and its relation to the Patent Foramen Ovale (PFO) is a long-debated topic. Recent clinical trials have unequivocally established the relationship between cryptogenic strokes and paradoxical embolism across the PFO. This slit-like communication exists in everyone before birth, but most often closes shortly after birth. PFO may persist as a narrow channel of communication between the right and left atria in approximately 25-27% of adults. In this review, we examine the clinical relevance of the PFO with analysis of the latest trials evaluating catheter-based closure of PFO's for cryptogenic stroke. We also review the current evidence examining the use of antiplatelet medications versus anticoagulants for stroke prevention in those patients with PFO who do not qualify for closure per current guidelines.

Management of Patients with Patent Foramen Ovale and Cryptogenic Stroke: An Update

Patent foramen ovale (PFO) is a common benign finding in healthy subjects, but its prevalence is higher in patients with stroke of unclear cause (cryptogenic stroke). PFO is believed to be associated with stroke through paradoxical embolism, and certain clinical and anatomical criteria seem to increase the likelihood of a PFO to be pathological. Recent trials have shown that closure of PFO, especially if associated with an atrial septal aneurysm and/or a large interatrial shunt, may reduce the risk of recurrent stroke as compared to medical treatment. However, it remains challenging to risk stratify patients with suspected PFO-related stroke and to decide if device closure is indicated. We sought to review contemporary evidence and to conclude an evidence-based strategy to prevent recurrence of PFO-related stroke.

Bi-Atrial Function before and after Percutaneous Closure of Atrial Septum in Patients with and without Paroxysmal Atrial Fibrillation: A 2-D and 3-D Speckle Tracking Echocardiographic Study

Our aim was to analyze atrial function with 2-D (2-D-STE) and 3-D (3-D-STE) speckle tracking echocardiography in patients with atrial septal devices and paroxysmal atrial fibrillation (PAF). One hundred sixteen patients and a subgroup of 22 patients who developed PAF after device insertion were studied. Left atrial and right atrial peak longitudinal strain and standard deviations of time to peak strain (TPS) were calculated using 2-D-STE. The left atrial/right atrial emptying fraction and expansion index were determined using 3-D-STE. By multivariate analysis, pre-closure 3-D right atrial expansion index, left atrial time to peak strain, and 3-D left atrial expansion index were independently associated with PAF. Compared with the other indices, receiver operating characteristic analysis revealed better diagnostic accuracy for the combination of pre-closure time to peak strain and 3-D expansion index in detecting PAF. Patients with atrial septal devices have pre-existing left and right atrial dilation and dysfunction as assessed by 2-D-STE and 3-D-STE that appear sensitive for the stratification of PAF risk in this population.

Established and potential echocardiographic markers of embolism and their therapeutic implications in patients with ischemic stroke

Cardiogenic strokes comprised 11% of all strokes and 25% of ischemic strokes. An accurate identification of the cause of stroke is necessary in order to prepare an adequate preventive strategy. In this review the confirmed and potential causes of embolic strokes are presented, which can be detected in echocardiography in the context of present treatment guidelines and gaps in evidence. There remains a need for further studies assessing the meaning of potential cardiac sources of embolism and establishment of rules for optimal medical prevention (antiplatelet therapy [APT] vs. oral anticoagulation [OAC]) and interventional procedures to reduce the incidence of ischemic strokes. Currently available data does not provide definitive evidence on the comparative benefits of OAC vs. APT in patients with cryptogenic stroke or embolic stroke of undetermined source. There is a lack of antithrombotic treatment scheme in the time between stroke and the completed diagnosis of potential sources of thromboembolism.

Computational Flow Dynamic Analysis of Right and Left Atria in Patent Foramen Ovale: Potential Links with Atrial Fibrillation

Background

An impairment of the left atrial function similar to that usually observed in atrial fibrillation (AF) has been observed also in patients with patent foramen ovale (PFO) and permanent right-to-left shunting (RLS).

Methods

We reconstructed the geometrical model of right atrium (RA), PFO, left atrium (LA) and left atrial appendage (LAA) of 65 patients with mild (36 patients mean age 45.5±6.8 years, 24 females) or permanent (29 patients, mean age 45.1±5.3 years, 21 females) RLS using anatomical data obtained by transoesophageal echocardiography (TEE) and cardiac MRI, performed as a part of our institutional screening protocol for paradoxical embolism. Using computational fluid dynamic analysis (CFD) we assessed the vorticity magnitude in both the LA and LAA to analyse a possible rheological relationship between PFO and AF.

Results

The anatomical models, in terms of dimensions, were comparable among the patients with mild and permanent RLS. A higher vorticity magnitude was observed in the mild shunt both in the LA (101.12±21.3 vs 88.3±22.6, p=0.02) and LAA (62±14.4 vs 32.4±12.3, p<0.01) when compared to the permanent R-L shunting.

Conclusion

The lower vorticity magnitude across the LA and LAA in patients with permanent RLS suggests a possible higher stagnation of the blood in these anatomical sites, similarly as previously observed in patients with AF.

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.

4D flow MRI assessment of right atrial flow patterns in the normal heart - influence of caval vein arrangement and implications for the patent foramen ovale

AIM

To investigate atrial flow patterns in the normal adult heart, to explore whether caval vein arrangement and patency of the foramen ovale (PFO) may be associated with flow pattern.

MATERIALS AND METHODS

Time-resolved, three-dimensional velocity encoded magnetic resonance imaging (4D flow) was employed to assess atrial flow patterns in thirteen healthy subjects (6 male, 40 years, range 25-50) and thirteen subjects (6 male, 40 years, range 21-50) with cryptogenic stroke and patent foramen ovale (CS-PFO). Right atrial flow was defined as vortical, helico-vortical, helical and multiple vortices. Time-averaged and peak systolic and diastolic flows in the caval and pulmonary veins and their anatomical arrangement were compared.

RESULTS

A spectrum of right atrial flow was observed across the four defined categories. The right atrial flow patterns were strongly associated with the relative position of the caval veins. Right atrial flow patterns other than vortical were more common (p = 0.015) and the separation between the superior and inferior vena cava greater (10±5mm versus 3±3mm, p = 0.002) in the CS-PFO group. In the left atrium all subjects except one had counter-clockwise vortical flow. Vortex size varied and was associated with left lower pulmonary vein flow (systolic r = 0.61, p = 0.001, diastolic r = 0.63 p = 0.002). A diastolic vortex was less common and time-averaged left atrial velocity was greater in the CS-PFO group (17±2cm/sec versus 15±1, p = 0.048). One CS-PFO subject demonstrated vortical retrograde flow in the descending aortic arch; all other subjects had laminar descending aortic flow.

CONCLUSION

Right atrial flow patterns in the normal heart are heterogeneous and are associated with the relative position of the caval veins. Patterns, other than 'typical' vortical flow, are more prevalent in the right atrium of those with cryptogenic stroke in the context of PFO. Left atrial flow patterns are more homogenous in normal hearts and show a relationship with flow arising from the left pulmonary veins.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Association of Left Atrial Enlargement with Cortical Infarction in Subjects with Patent Foramen Ovale

Background and Purpose

Left atrial dysfunction has been reported in patients with patent foramen ovale (PFO). Here we investigated the role of left atrial dysfunction in the development of embolic stroke in patients with PFO.

Methods

We identified consecutive patients with embolic stroke of undetermined sources except for PFO (PFO+ESUS). Healthy subjects with PFO served as controls (PFO+control). A stratified analysis by 10-year age group and an age- and sex- matching analysis were performed to compare echocardiographic markers between groups. In the PFO+ESUS group, infarct patterns of PFO-related stroke were determined (cortical vs. cortico-subcortical) and analyzed in correlation with left atrial function parameters.

Results

A total of 118 patients and 231 controls were included. The left atrial volume indices (LAVIs) of the PFO+ESUS patients were higher than those of the PFO+controls in age groups of 40–49, 50–59, and 60–69 years (P<0.001, P=0.003, and P=0.027, respectively), and in the age- and sex-matched analysis (P=0.001). In the PFO+ESUS patients, a higher (>28 mL/m²) LAVI was more associated with the cortical infarct pattern (P=0.043 for an acute infarction and P=0.024 for a chronic infarction, both adjusted for age and shunt amount). The degree of right-to-left shunting was not associated with infarct patterns, but with the posterior location of acute infarcts (P=0.028).

Conclusions

Left atrial enlargement was associated with embolic stroke in subjects with PFO. Left atrial physiology might contribute to the development of PFO-related stroke and need to be taken into consideration for optimal prevention of PFO-related stroke.

Patent Foramen Ovale and Stroke-Current Status

Patent foramen ovale (PFO) is growing in clinical interest because of a renewed focus on embolic stroke of undetermined source (ESUS), the PFO attributable fraction (the 10-point Risk of Paradoxical Embolism score), technical advances in PFO diagnosis, and the emergence of endovascular device closure as a treatment option. However, recent randomized controlled trials of the management of patients with ESUS and PFO failed to demonstrate the superiority of closure over medical treatment. The mechanisms of stroke other than paradoxical embolism may be important in patients with ESUS and PFO. This paper reviews the current understanding of the pathophysiology of stroke and therapeutic options in patients with PFO and ESUS.

Pathophysiology of paradoxical embolism: evaluation of the role of interatrial septum anatomy based on the intracardiac echocardiography assessment of patients with right-to-left shunting

BACKGROUND

Detailed anatomic variants of the interatrial septum in patients with right-to-left shunt and contribution of specific anatomies to the risk of ischaemic recurrences has not yet been comprehensively classified.

OBJECTIVE

To report a classification of the anatomic variants of the interatrial septum as observed by intracardiac echocardiography and its correlation with clinical and functional characteristics.

METHODS

We retrospectively reviewed the medical and instrumental data of 520 consecutive patients (mean age 44±15. 5 years, 355 women) who had over a 10-year period undergone intracardiac echocardiography and right-to-left shunt catheter-based closure. The four main features used to analyse were: (a) diameter of the oval fossa, (b) presence and length of the channel, (c) presence and degree of atrial septal aneurysm, and (d) rim thickness. The presence of Eustachian valve was also tabulated.

RESULTS

The combinations of interatrial septum anatomical features were classified into six main anatomical subgroups. Recurrent embolism, multiple ischaemic foci on brain magnetic resonance imaging, high grade shunt, and permanent shunt before transcatheter closure procedure were associated with type 2, type 4, and type 6. Type 4 anatomical subtype (OR 4.1, 1.5-8 [95% CI], p<0.001) and type 2+presence of Eustachian valve (OR 4.3, 1.6-9 [95% CI], p<0.001) were the strongest predictors of recurrent ischaemic events before transcatheter closure.

CONCLUSION

Our study showed that interatrial septum anatomy greatly differs among patients with right-to-left shunt, as well as the risk of ischaemic recurrences in different anatomies.

Clinical, hemodynamic, and intracardiac echocardiographic characteristics of secundum atrial septal defects-related paradoxical embolism in adulthood

BACKGROUND

Paradoxical embolism associated with secundum atrial septal defect (sASD) is a relatively rare but well-known occurrence. The purpose of our study is to report the clinical, hemodynamic, and anatomical features assessed by intracardiac echocardiography (ICE) of sASD as related to paradoxical embolism.

METHODS

Five hundred thirty-seven patients (mean age 48 ± 19.0 years) admitted for transcatheter repair of interatrial shunts were enrolled in a prospective registry over a 10-year period (September 2003-September 2013). All patients underwent transesophageal echocardiography, complete right and left catheterization, prior to the device-based procedure. ICE was performed in all patients in order to investigate the interatrial septum anatomy and to monitor device implantation. These results were compared with the data of patients with patent foramen ovale (PFO) patients and nonemboligenous sASD admitted at the same time period.

RESULTS

Twenty-four patients (6.2%) out of 386 who underwent transcatheter repair for paradoxical embolism had a secundum ASD. The defects were cribrosus in 41.6% (10/24). All single sASD (58.3%) had a peculiar anatomical feature a so-called flat elliptical shape with a major axis of 7.6 ± 2.4 and minimal axis of 2.5 ± 1.6 mm. Patients with sASD-related paradoxical embolism had a higher frequency of deep venous thrombosis compared to PFO patients. In comparison to nonemboligenous sASD, such patients had lower mean pulmonary pressure and smaller defects.

CONCLUSION

sASD related to paradoxical embolism had peculiar clinical, hemodynamic, and anatomical characteristics, which classified such defects in the middle of the spectrum between nonemboligenous secundum ASD and PFO.