Prevalence and characteristics of patent foramen ovale in a sample of Egyptian population: a computed tomography study

BACKGROUND

The reported prevalence of patent foramen ovale (PFO) in the general population is variable. It ranges between 8.6 and 42% according to the population studied and the imaging technique used. We aim to prospectively assess the prevalence and characteristics of PFO and interatrial septum (IAS) abnormalities as well as the related clinical manifestations in a sample of Egyptian population.

RESULTS

This study comprised 1000 patients who were referred for CT coronary angiography (CTCA). Mean age was 52.5 ± 10.9 years. The prevalence of PFO among the studied population was 16.3%; closed PFO (grade I) 44.2%, open PFO (grade II) 50.9%, and open PFO with jet (grade III) 4.9%. Anatomical high-risk PFO features-defined as the presence of at least 2 or more of the following (diameter ≥ 2 mm, length ≥ 10 mm, septal aneurysm "ASA", or redundant septum)-were found in 51.5% of PFOs' population. Other IAS abnormalities as redundant septum (8.6%), ASA (5.3%), Bachmann's bundle (4.5%), microaneurysm (2.6%), and atrial septal defect (ASD) (0.4%) were detected. There was a lower rate of coexistence of ASA with PFO (p = 0.031). Syncope was significantly higher in patients with PFO compared to those without PFO (6.7% vs. 1.6%, p = 0.001). Stroke, transient ischaemic attacks (TIA), and dizziness were similar in both groups. TIA, dizziness, and syncope were significantly higher in patients with IAS abnormalities including PFO compared to those without IAS abnormalities. Syncope was also significantly higher in PFO with high-risk anatomical features compared to those with non-high-risk PFO population (p = 0.02).

CONCLUSION

The prevalence of PFO in our study was approximately 16.3%, almost half of them showed anatomical high-risk features for stroke. Dizziness, syncope and TIA were significantly higher in patients with IAS abnormalities including PFO.

Evaluation and Utilization of Flow Artifacts at CT

Flow artifacts are commonly encountered at contrast-enhanced CT and can be difficult to discern from true pathologic conditions. Therefore, radiologists must be comfortable distinguishing flow artifacts from true pathologic conditions. This is of particular importance when evaluating the pulmonary arteries and aorta, as a flow artifact may be mistaken for a pulmonary embolism or dissection flap. Understanding the mechanics of flow artifacts and how these artifacts are created can help radiologists in several ways. First, this knowledge can help radiologists appreciate how the imaging characteristics of flow artifacts differ from true pathologic conditions. This information can also help radiologists better recognize the clinical conditions that predispose patients to flow artifacts, such as pneumonia, chronic lung damage, and altered cardiac output. By understanding when flow artifacts may be confounding the interpretation of an examination, radiologists can then know when to pursue other troubleshooting methods to assist with the diagnosis. In these circumstances, the radiologist can consider several troubleshooting methods, including adjusting the imaging protocols, recommending when additional imaging may be helpful, and suggesting which imaging study would be the most beneficial. Finally, flow artifacts can also be used as a diagnostic tool when evaluating the vascular anatomy, examples of which include the characterization of shunts, venous collaterals, intimomedial flaps, and alternative patterns of blood flow, as seen in extracorporeal membrane oxygenation circuits. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

A Multidisciplinary Algorithm for the Evaluation of Acute Neurologic Deficits Improves Management of Cryptogenic Stroke or Transient Ischemic Attack

The appropriate diagnosis and management of cryptogenic stroke and transient ischemic attack (TIA) is challenging and requires multidisciplinary involvement. Joint societal guidelines exist to guide the comprehensive evaluation of these entities. This study aimed to implement a standardized multidisciplinary diagnostic algorithm for cryptogenic stroke/TIA. We performed a retrospective analysis of patients admitted to the largest regional military healthcare center with stroke or TIA considered to be cryptogenic at the time of discharge. We abstracted baseline demographics and rates of extra- and intracranial imaging, transthoracic and transesophageal echocardiography, and event monitor orders at the time of discharge. The incidence of event monitor results at 30 days and six months were included. A diagnostic algorithm for evaluation of cryptogenic stroke/TIA was created and disseminated hospital-wide using increased compliance with neuroimaging, echocardiography, and cardiac rhythm monitoring as primary endpoints for our intervention. Post-intervention data abstraction revealed similar rates of extra- and intracranial imaging, but significantly greater rates of transthoracic echocardiography (70% vs. 87%, p 0.0073), inclusion of agitated saline study (41% vs. 65%, p 0.0024), and event monitors ordered at discharge (18% vs. 35%, p 0.0045). At six months there was a higher rate of event monitors obtained (24% vs. 45%, p 0.001). Our study showed implementation of an evidence-based diagnostic algorithm for evaluation of cryptogenic stroke/TIA increases appropriate use of echocardiography and event monitoring.

Evaluation of causal heart diseases in cardioembolic stroke by cardiac computed tomography

Cardioembolic stroke is a potentially devastating condition and tends to have a poor prognosis compared with other ischemic stroke subtypes. Therefore, it is important for proper therapeutic management to identify a cardiac source of embolism in stroke patients. Cardiac computed tomography (CCT) can detect the detailed visualization of various cardiac pathologies in the cardiac chambers, interatrial and interventricular septum, valves, and myocardium with few motion artifacts and few dead angles. Multiphase reconstruction images of the entire cardiac cycle make it possible to demonstrate cardiac structures in a dynamic manner. Consequently, CCT has the ability to provide high-quality information about causal heart disease in cardioembolic stroke. In addition, CCT can simultaneously evaluate obstructive coronary artery disease, which may be helpful in surgical planning in patients who need urgent surgery, such as cardiac tumors or infective endocarditis. This review will introduce the potential clinical applications of CCT in an ischemic stroke population, with a focus on diagnosing cardioembolic sources using CCT.

Diagnostic Performance of Cardiac Computed Tomography for Detecting Patent Foramen Ovale: Evaluation Using Transesophageal Echocardiography and Catheterization as Reference Standards

BACKGROUND

Patent foramen ovale (PFO) is associated with various diseases such as cryptogenic stroke, migraine, and platypnea-orthodeoxia syndrome. This study aimed to evaluate the diagnostic performance of cardiac computed tomography (CT) for PFO detection.

MATERIALS AND METHODS

Consecutive patients diagnosed with atrial fibrillation and who underwent catheter ablation with pre-procedural cardiac CT and transesophageal echocardiography (TEE) were enrolled in this study. The presence of PFO was defined as (1) the confirmation of PFO using TEE and/or (2) the catheter crossing the interatrial septum (IAS) into the left atrium during ablation. CT findings indicative of PFO included (1) the presence of a channel-like appearance (CLA) on the IAS and (2) a CLA with a contrast jet flow from the left atrium to the right atrium. The diagnostic performance of both a CLA alone and a CLA with a jet flow was evaluated for PFO detection.

RESULTS

Altogether, 151 patients were analyzed in the study (mean age, 68 years; men, 62%). Twenty-nine patients (19%) had PFO confirmed by TEE and/or catheterization. The diagnostic performance of a CLA alone was as follows: sensitivity, 72.4%; specificity, 79.5%; positive predictive value (PPV), 45.7%; negative predictive value (NPV), 92.4%. The diagnostic performance of a CLA with a jet flow was as follows: sensitivity, 65.5%; specificity, 98.4%; PPV, 90.5%; NPV, 92.3%. The diagnostic performance of a CLA with a jet flow was statistically superior to that of a CLA alone (p = 0.045), and the C-statistics were 0.76 and 0.82, respectively.

CONCLUSION

A CLA with a contrast jet flow in cardiac CT has a high PPV for PFO detection, and its diagnostic performance is superior to that of a CLA alone.

Detection of patent foramen ovale in patients with ischemic stroke on prospective ECG-gated cardiac CT compared to transthoracic echocardiography

BACKGROUND

Cardiac CT acquired during the acute stroke imaging protocol is an emerging alternative to transthoracic echocardiography (TTE) to screen for sources of cardioembolism. Currently, its diagnostic accuracy to detect patent foramen ovale (PFO) is unclear.

METHODS

This was a substudy of Mind the Heart, a prospective cohort in which consecutive adult patients with acute ischemic stroke underwent prospective ECG-gated cardiac CT during the initial stroke imaging protocol. Patients also underwent TTE. We included patients < 60 years who underwent TTE with agitated saline contrast (cTTE) and assessed sensitivity, specificity, negative and positive predictive value of cardiac CT for the detection of PFO using cTTE as the reference standard.

RESULTS

Of 452 patients in Mind the Heart, 92 were younger than 60 years. Of these, 59 (64%) patients underwent both cardiac CT and cTTE and were included. Median age was 54 (IQR 49-57) years and 41/59 (70%) were male. Cardiac CT detected a PFO in 5/59 (8%) patients, 3 of which were confirmed on cTTE. cTTE detected a PFO in 12/59 (20%) patients. Sensitivity and specificity of cardiac CT were 25% (95% CI 5-57%) and 96% (95% CI 85-99%), respectively. Positive and negative predictive values were 59% (95% CI 14-95) and 84% (95% CI 71-92).

CONCLUSION

Prospective ECG-gated cardiac CT acquired during the acute stroke imaging protocol does not appear to be a suitable screening method for PFO due to its low sensitivity. Our data suggest that if cardiac CT is used as a first-line screening method for cardioembolism, additional echocardiography remains indicated in young patients with cryptogenic stroke, in whom PFO detection would have therapeutic consequences. These results need to be confirmed in larger cohorts.

Physiological fetal vascular shunts and failure to regress: what the radiologist needs to know

The fetal circulation is characterized by the presence of three physiological vascular shunts - the ductus arteriosus, the foramen ovale and the ductus venosus. Acting in concert, these shunts preferentially stream blood flow in a pattern that maximizes efficiency of blood oxygenation by the maternofetal unit. Shortly following the transition to extrauterine life, a quick and predetermined succession of events results in closure of these embryological structures with consequent establishment of postnatal vascular flow patterns. While this transition is often seamless, the physiological shunts of the fetus occasionally fail to regress. Such failure to regress can occur in isolation or in association with other congenital malformations. This failed regression challenges the circulatory physiology of the neonate and might have implications for the optimum functioning of several organ systems. When symptomatic, these shunts are treated. Interventions, when undertaken, might be medical, endovascular or surgical. The radiologist's role continues to expand in the assessment of these shunts, in providing a roadmap for treatment and in prompt identification of treatment-related complications. This review is to familiarize radiologists with the embryology, pre- and post-treatment imaging appearances, and associated complications of persistent fetal vascular shunts.

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.

Assessing patent foramen ovale on coronary computed tomographic angiography: a comparison with transesophageal echocardiography

PURPOSE

This study was undertaken to determine if coronary computed tomographic angiography (CCTA) can help to assess patent foramen ovale (PFO) with high accuracy and reproducibility when compared to transesophageal echocardiography (TEE).

MATERIALS AND METHODS

In total, 75 suspected PFO cases (31 men, 44 women; mean age, 45 ± 9 years) were evaluated by coronary CTA and TEE. PFO tunnel length (TL) and the opening diameter of the left atrial entrance (ODLAE) and right atrial entrance (ODRAE), as well as contrast shunt (if present due to PFO), were measured by both modalities.

RESULTS

PFO was detected in 68 patients with TEE. The sensitivity for the detection of PFO with CCTA was 85.3%; specificity, 71.4%; positive predictive value, 96.7%; and negative predictive value, 33.3%. Both modalities demonstrated good agreement in measuring TL and ODLAE of PFO. However, the ODRAE of TEE was different from that of CCTA (1.14 ± 0.4 mm and 1.45 ± 0.5 mm, respectively, p = 0.04). The intra-observer and inter-observer variability and agreement for TL, ODRAE, and ODLAE of PFO were excellent between the two measurements.

CONCLUSION

CCTA provided a method for detection of PFO with high accuracy and reproducibility compared with TEE. Therefore, CCTA is a practical and efficient alternative to TEE for PFO diagnosis.

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.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

The role of cardiac CT throughout the full cardiac cycle in diagnosing patent foramen ovale in patients with acute stroke

OBJECTIVES

We explored the hypothesis that the diagnostic performance of cardiac computed tomography (CT) throughout the full cardiac cycle would be superior to single-phase CT and comparable to transesophageal echocardiography (TEE) in diagnosing patent foramen ovale (PFO).

METHODS AND RESULTS

From May 2011 to April 2015, 978 patients with stroke were diagnosed with PFO by TEE. In patients with stroke, cardiac CT was performed if the patients had more than two cardiovascular risk factors. We prospectively enrolled 70 patients with an indication for cardiac CT. Cardiac CT images were reconstructed at 10% increments of the R-R interval. The sensitivity of cardiac CT throughout the full cardiac cycle in diagnosing PFO was compared to that for TEE and single-phase cardiac CT. To evaluate the specificity of cardiac CT, we analyzed patients without PFO confirmed by TEE who underwent cardiac CT within 1 month of pre-cardiac surgery. Sixty-six patients with cardiac CT and TEE were included in the final analysis. Throughout the full cardiac cycle, cardiac CT had a sensitivity of 89.4% and a specificity of 92.3% in diagnosing PFO, compared to TEE as a reference. PFO was primarily detected in the 60% and 70% intervals in 10-phase reconstructed images. The sensitivity of PFO diagnosis with cardiac CT was 81.8% when analyzing both the 60% and 70% intervals instead of the full cardiac cycle.

CONCLUSION

Cardiac CT throughout the full cardiac cycle outperforms single-phase cardiac CT in detecting PFO. Cardiac CT can be used as an alternative method to TEE for detecting PFO in stroke patients.

KEY POINTS

• Throughout the full cardiac cycle, cardiac computed tomography (CT) had a sensitivity of 89.4% and a specificity of 92.3% in diagnosing patent foramen ovale (PFO), compared to transesophageal echocardiography. • The sensitivity of diagnosing patent foramen ovale with cardiac CT was 81.8% when analyzing 60% and 70% R-R intervals instead of the full cardiac cycle. • Cardiac CT with retrospective electrocardiographic gating throughout the full cardiac cycle can increase the detectability of PFO, compared to single-phase cardiac CT.

Cardiac Imaging After Ischemic Stroke or Transient Ischemic Attack

PURPOSE OF REVIEW

Cardiac imaging after ischemic stroke or transient ischemic attack (TIA) is used to identify potential sources of cardioembolism, to classify stroke etiology leading to changes in secondary stroke prevention, and to detect frequent comorbidities. This article summarizes the latest research on this topic and provides an approach to clinical practice to use cardiac imaging after stroke.

RECENT FINDINGS

Echocardiography remains the primary imaging method for cardiac work-up after stroke. Recent echocardiography studies further demonstrated promising results regarding the prediction of non-permanent atrial fibrillation after ischemic stroke. Cardiac magnetic resonance imaging and computed tomography have been tested for their diagnostic value, in particular in patients with cryptogenic stroke, and can be considered as second line methods, providing complementary information in selected stroke patients. Cardiac imaging after ischemic stroke or TIA reveals a potential causal condition in a subset of patients. Whether systematic application of cardiac imaging improves outcome after stroke remains to be established.

Potential Role of 2-Phase Cardiac CT in Patients With Embolic Stroke of Undetermined Source

BACKGROUND

Recent trials failed to demonstrate that anticoagulation was superior to antiplatelet agents in preventing recurrent stroke after embolic stroke of undetermined source (ESUS), which may be as a result of the heterogeneity of etiology. We thus investigated whether the use of 2-phase cardiac computed tomography (CT) could help to evaluate the etiology in patients with ESUS.

METHODS

We performed 2-phase cardiac CT in patients with ESUS and evaluated whether there was positive cardiac findings.

RESULTS

A total of 74 patients with ESUS were enrolled. Positive cardiac findings were found in 21 (28.4%) patients, including intracardiac thrombus (n = 5), complex aortic plaque (n = 9), and patent foramen ovale (PFO) (n = 8). Both complex aortic plaque and patent foramen ovale were identified in 1 patient.

CONCLUSIONS

Two-phase cardiac CT is a useful tool for stroke etiology evaluation, providing diagnostic information in a quarter of patients with ESUS.

Cardiovascular computed tomography versus transoesophageal echocardiography after cryptogenic ischaemic stroke – a pilot study of 12 patients

Objective

Transoesophageal echocardiography (TEE) is the gold standard for the detection of cardiac emboli sources in ischaemic stroke patients, but new computed tomography (CT) scanners are able to visualize the heart. This pilot study aimed to compare findings on TEE with combined cardiovascular scan and cerebral CT angiography in cryptogenic ischaemic stroke patients.

Methods

This pilot study enrolled patients with cryptogenic ischaemic stroke who underwent a combined cardiovascular and cerebral CT angiography scan and a TEE examination, which were interpreted in a blinded manner.

Results

Twelve patients with cryptogenic ischaemic stroke were included (mean age 56 years). Of these, 10 patients underwent both a combined cardiovascular and cerebral CT angiography and a TEE examination. All cardiovascular CT scans were readable at sinus rhythm. None of the simultaneous cerebral angiograms were compromised. Thrombi were not detected in any patients. Patent foramen ovale was visualized in five patients by TEE, while cardiovascular CT only identified three. Cardiovascular CT revealed in addition an X-ray negative pulmonary metastasis in one patient, aortic coarctation in another and significant coronary stenosis in four patients.

Conclusion

The sensitivity for detecting patent foramen ovale was considerably lower for cardiovascular CT than for TEE, however the cardiovascular CT revealed several other very important clinical findings.

Cardiac imaging after ischemic stroke : Echocardiography, CT, or MRI?

About 20–25% of all ischemic strokes are of cardioembolic etiology, with atrial fibrillation and heart failure as the most common underlying pathologies. Diagnostic work-up by noninvasive cardiac imaging is essential since it may lead to changes in therapy, e.g., in—but not exclusively—secondary stroke prevention. Echocardiography remains the cornerstone of cardiac imaging after ischemic stroke, with the combination of transthoracic and transesophageal echocardiography as gold standard thanks to their high sensitivity for many common pathologies. Transesophageal echocardiography should be considered as the initial diagnostic tool when a cardioembolic source of stroke is suspected. However, to date, there is no proven benefit of transesophageal echocardiography-related therapy changes on the main outcomes after ischemic stroke. Based on the currently available data, cardiac computed tomography and magnetic resonance imaging should be regarded as complementary methods to echocardiography, providing additional information in specific situations; however, they cannot be recommended as first-line modalities.

A case of iatrogenic air bubbles in the left ventricle by coronary computed tomographic angiography

We report a case of asymptomatic iatrogenic air bubbles in the left ventricle observed by coronary computed tomographic angiography. Air bubbles are rarely found in the left ventricle and could prove fatal should they migrate to the brain or coronary arteries. We believe that the cause is micro air bubbles in the tubing system between the intravenous catheter and power injector.

The role of coronary CT angiography in diagnosis of patent foramen ovale

PURPOSE

We aimed to examine the incidence of patent foramen ovale (PFO) and atrial septal aneurysms (ASA) in the Turkish population using coronary computed tomography angiography (CTA); assess the feasibility of coronary CTA for PFO diagnosis by conducting a comparison with transthoracic echocardiography (TTE); and determine the diagnostic role and characteristics of the interatrial tunnel, free flap valve (FFV), and shunts.

METHODS

The present study was conducted retrospectively and included a sample of 782 patients. Coronary CTA results for all patients were evaluated for the following parameters: the presence of PFO, the degree of contrast jet (if present due to PFO), ASA existence, free flap valve (FFV) length, and PFO tunnel diameters (1 and 2). Coronary CTA and TTE results for PFO detection were also compared for 19 patients who underwent both procedures.

RESULTS

PFO was present in 118 patients (15%). In 19 patients who underwent both CTA and TTE, the shunt was present in 15 patients on TTE compared with nine patients on CTA. The sensitivity and specificity of CTA for shunt existence were 53% (8/15) and 75% (3/4), respectively. FFV was observed on CTA in 118 patients (15%). No significant relationship was observed between shunt existence and FFV length (P = 0.148), or between shunt existence and tunnel diameter-1 (P = 0.638) or diameter-2 (P = 0.058). ASAs were present in 16 patients (2%), while accompanying PFO was present in three patients (2.4%).

CONCLUSION

Coronary CTA constitutes a more practical and efficient alternative to TTE for PFO diagnosis. Further, it allows the clear visualization of anatomical details of the interatrial tunnel, shunts, and associated abnormalities and detects ASAs.

The relationship of patent foramen ovale location with severity of stroke: A new risk factor for paradoxical embolism

OBJECTIVE

Patent foramen ovale (PFO) is a common developmental anomaly and is well associated with paradoxical embolism and cryptogenic stroke. The aim of this study was to investigate the relationship of PFO location with severity of cryptogenic stroke.

MATERIALS AND METHODS

Fifty patients with cryptogenic stroke and echocardiographically proven PFO were classified according to the severity of stroke. In order to define the location of PFOs, an imaginary line dividing the length of interatrial septum vertically into two equal parts was drawn manually at axial plane on cardiac multidetector computed tomography. PFOs located at superior part of this imaginary line was defined as superiorly located PFO, while PFOs located at inferior part of this imaginary line was defined as inferiorly located PFO.

RESULTS

Fourteen patients (28%) revealed mild, 20 patients (40%) revealed moderate and 16 patients (32%) had severe stroke. Based on PFO location, there were 34 patients (68%) with superiorly (group 1), and 16 patients (32%) with inferiorly (group 2) located PFO. It was found that patients of group 1 had significantly higher frequency of moderate or severe stroke compared to those of group 2 (p < 0.005) CONCLUSION: In conclusion, the patients with superiorly located PFO had higher frequency of severe stroke compared to the patients with inferiorly located PFO. Since this is a preliminary study, clinical application and importance of this finding necessitates further large-scale interventional studies.

Potential Utility of Multidetector Computed Tomography to Identify both Cardiac Embolic Sources and Coronary Artery Disease in Patients with Embolic Stroke

OBJECTIVES

Our objective was to study the potential utility of multidetector computed tomography (MDCT) to identify both cardiac embolic sources and coronary artery disease (CAD) in embolic-stroke patients.

METHODS

We performed MDCT for 184 patients with embolic stroke but without known CAD. Twenty-six patients had atrial fibrillation. We investigated the prevalence of the potential source of the embolism and the coronary characteristics.

RESULTS

Overall, 64 potential embolic sources were detected in 59 patients (32.1%). Left atrial appendage thrombus, left ventricular thrombus and aortic atheroma were detected in 3.3, 0.5 and 15.8% of patients, respectively. Circulatory stasis and patent foramen ovale were detected in 8.7 and 6.5%, respectively. As for coronary calcium score, only 47 patients (25.5%) had a score of zero and 51 (27.7%) had a score of ≥ 400. Significant CAD was detected in 18 patients (9.8%). One hundred and thirty-seven (74.5%) had coronary plaques. The prevalence of positive remodeling, low-attenuation plaque, spotty calcification and a napkin-ring sign was 7.1, 1.6, 5.4 and 2.7%, respectively. Importantly, only 34 patients (13.0%) had no abnormalities detected by MDCT.

CONCLUSIONS

Our results suggest that MDCT has potential to identify both cardiac embolic sources and CAD in patients with embolic stroke but without known CAD.

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.

MDCT of interatrial septum

ECG-gated cardiac multidetector row computed tomography (MDCT) allows precise analysis of the interatrial septum (IAS). This pictorial review provides a detailed description of the normal anatomy, variants and abnormalities of the IAS such as patent foramen ovale, congenital abnormalities such as atrial septal defects as well as tumors and tumoral-like processes that develop on the IAS.

Cardiac CT angiography beyond the coronary arteries: what radiologists need to know and why they need to know it

OBJECTIVE

With current state-of-the-art CT combining fast scanning times and high spatial resolution, anatomy beyond the coronary arteries is well visualized and may lead to discovery of abnormalities. The purpose of this article is to provide a strategy for radiologists to recognize important extracoronary cardiac CT angiography (CTA) findings.

CONCLUSION

A systemic approach to cardiac CTA by anatomic location and attention to key CT features are critical to identify and properly characterize important extracoronary cardiac abnormalities.

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

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

Lack of association between stroke and left atrial out-pouching structures: results of a case-control study

Background and Purpose

Clinical significance of out-pouching structures of the left atrium (LA) as potential embolic sources remains unclear. We sought to evaluate the association between stroke and LA out-pouching structures.

Methods

A case-control study was conducted to assess the prevalence of LA out-pouching structures in subjects with and without stroke. Case subjects were 270 stroke patients who had undergone cardiac CT. Control subjects were 270 age- and sex-matched patients without a history of stroke and who had undergone cardiac CT. Presence of LA out-pouching structures was determined by ECG-gated cardiac CT. The location of out-pouching structures was categorized as near Bachmann bundle, anterior, inferoseptal, inferior, and lateral. The prevalence, number and location of out-pouching structures and clinical characteristics were compared between the two groups.

Results

One hundred sixty eight out-pouching structures were identified in 139 stroke patients (51%), while a total of 169 out-pouching structures were found in 155 control patients (57%) (p=0.1949). The prevalence of LA out-pouching structures with different locations was not significantly different between the stroke group and control group. In the stroke group, the prevalence of out-pouching structures was not significantly different by subtypes of ischemic stroke and the prevalence of LA out-pouching structures was not different between patients with atrial fibrillation (AF) and without AF.

Conclusion

The left atrial out-pouching structures are commonly seen in a population with and without stroke with similar prevalence. Our study suggests that LA out-pouching structures are not significant risk factors of stroke.

Impact of cardiac computed tomography of the interatrial septum before pulmonary vein isolation

BACKGROUND

Multidetector computed tomography (MDCT) may be useful to identify patients with patent foramen ovale (PFO). The aim of this study was to analyze whether a MDCT performed before pulmonary vein isolation reliably detects a PFO that may be used for access to the left atrium.

METHODS AND RESULTS

In 79 consecutive patients, who were referred for catheter ablation of symptomatic paroxysmal or persistent atrial fibrillation (AF), the presence of a PFO was explored by MDCT and transesophageal echocardiography (TEE). TEE was considered as the gold standard, and quality of TEE was good in all patients. In 16 patients (20.3%), MDCT could not be used for analysis because of artifacts, mainly because of AF. On TEE, a PFO was found in 15 (23.8%) of the 63 patients with usable MDCT. MDCT detected six PFO of which four were present on TEE. This corresponded to a sensitivity of 26.7%, a specificity of 95.8%, a negative predictive value of 80.7%, and a positive predictive value of 66.7%. The receiver operating characteristics curve of MDCT for the detection of PFO was 0.613 (95% confidence interval 0.493-0.732).

CONCLUSIONS

MDCT may detect a PFO before pulmonary isolation. However, presence of AF may lead to artifacts on MDCT impeding a meaningful analysis. Furthermore, in this study sensitivity and positive predictive value of MDCT were low and therefore MDCT was not a reliable screening tool for detection of PFO.

Interatrial shunt: diagnosis of patent foramen ovale and atrial septal defect with 64-row coronary computed tomography angiography

PURPOSE

The aim of this study was to investigate the frequency with which interatrial shunts are found during routine coronary computed tomography (CT) angiography and to describe imaging characterizations of patent foramen ovale (PFO), atrial septal defect (ASD), and atrial septal aneurysm (ASA).

MATERIALS AND METHODS

A total of 1081 adult patients were evaluated retrospectively for interatrial shunting; 77 were excluded from the study. CT diagnosis of PFO was defined as (1) a channel-like appearance of the interatrial septum (IAS) and (2) a contrast agent jet flow from the left atrium (LA) to the right atrium (RA). ASD was defined as (1) the IAS resembling a membrane with a hole and (2) a contrast jet flow between the two atria. ASA was identified by detecting a minimum 10-mm protrusion of the LA beyond the IAS into the RA.

RESULTS

Among 1004 patients, 86 patients (8.6%) were diagnosed to have PFO. Another 23 patients (2.3%) had a hole in the IAS and were diagnosed as having ASD: 21 with an ostium secundum-type ASD and 2 with the sinus venosus type. ASA accompanied ASD in three patients.

CONCLUSION

Electrocardiography-gated CT using the saline-chaser contrast injection technique that is routinely used for coronary arterial imaging can be used to detect interatrial shunts. The technique can also serve as a method for differentiating PFO, ASD, and ASA.

Blood pressure treatment in acute ischemic stroke: a review of studies and recommendations

PURPOSE OF REVIEW

Elevated blood pressure (BP) is frequent in patients with acute ischemic stroke. Pathophysiological data support its usefulness to maintain adequate perfusion of the ischemic penumba. This review article aims to summarize the available evidence from clinical studies that examined the prognostic role of BP during the acute phase of ischemic stroke and intervention studies that assessed the efficacy of active BP alteration.

RECENT FINDINGS

We found 34 observational studies (33,470 patients), with results being inconsistent among the studies; most studies reported a negative association between increased levels of BP and clinical outcome, whereas a few studies showed clinical improvement with higher BP levels, clinical deterioration with decreased BP, or no association at all. Similarly, the conclusions drawn by the 18 intervention studies included in this review (1637 patients) were also heterogeneous. Very recent clinical data suggest a possible beneficial effect of early treatment with some antihypertensives on late clinical outcome.

SUMMARY

Observational and interventional studies of management of acute poststroke hypertension yield conflicting results. We discuss different explanations that may account for this and discuss the current guidelines and pathophysiological considerations for the management of acute poststroke hypertension.

ASCI 2010 appropriateness criteria for cardiac computed tomography: a report of the Asian Society of Cardiovascular Imaging Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging Guideline Working Group

In Asia, the healthcare system, populations and patterns of disease differ from Western countries. The current reports on the criteria for cardiac CT scans, provided by Western professional societies, are not appropriate for Asian cultures. The Asian Society of Cardiovascular Imaging, the only society dedicated to cardiovascular imaging in Asia, formed a Working Group and invited 23 Technical Panel members representing a variety of Asian countries to rate the 51 indications for cardiac CT in clinical practice in Asia. The indications were rated as 'appropriate' (7-9), 'uncertain' (4-6), or 'inappropriate' (1-3) on a scale of 1-9. The median score was used for the final result if there was no disagreement. The final ratings for indications were 33 appropriate, 14 uncertain and 4 inappropriate. And 20 of them are highly agreed (19 appropriate and 1 inappropriate). Specifically, the Asian representatives considered cardiac CT as an appropriate modality for Kawasaki disease and congenital heart diseases in follow up and in symptomatic patients. In addition, except for some specified conditions, cardiac CT was considered to be an appropriate modality for one-stop shop ischemic heart disease evaluation due to its general appropriateness in coronary, structure and function evaluation. This report is expected to have a significant impact on the clinical practice, research and reimbursement policy in Asia.