Cause Of Cardioembolic Stroke Research Articles

Restrictive cardiomyopathy a missed cause of cardioembolic stroke in young patients

Restrictive cardiomyopathy is characterized by restrictive filling and reduced diastolic volume of either or both ventricles with normal or near-normal systolic function and wall thickness. Here, author reports a case of 18-year-old boy who presented with cardioembolic stroke. On further workup, restrictive physiology was identified and possibility of constrictive pericarditis (CP) could not be ruled out on two-dimensional echocardiographic examination, which was subsequently ruled out by 64 slice cardiac computed tomography scan. The identification of the condition is important for the point of diagnosis and management; rheumatic valvular diseases are prevalent most commonly and are a source of embolism for ischemic stroke in young patients. CP is also common due to high prevalence of tuberculosis in India, which poses diagnostic difficulties.

Cardioembolic stroke: a variety of causes and current approaches to its prevention

Based on the data available in the literature and the results of their investigations, the authors give the present-day views of the role and place of cardiac diseases in the pathogenesis of cardioembolic stroke (CES). Among all causes of ischemic strokes, cardiogenic strokes are demonstrated to account for as high as 40%. Nonrheumatic atrial fibrillation, postinfarction changes, and rheumatic heart diseases are considered to be the leading causes of CES. Current recommendations for CES prevention are presented; the specific features of antithrombotic therapy are analyzed in detail.

Current approaches to antithrombotic therapy in patients with cardioembolic stroke

The rate of cardiogenic embolism among all ischemic strokes is as high as 38%. Cardioembolic strokes are characterized by the higher magnitude of neurological deficit, the high risk of recurrent acute stroke, and a lethal outcome. This review deals with the etiopathogenesis of thrombus formation in the heart chambers, with current criteria for the verification of cardioembolic strokes, with the results of trials of new oral anticoagulants, and latest guidelines for antithrombotic therapy to prevent stroke. Special focus is given to secondary stroke prevention in patients with nonvalvular atrial fibrillation since it is atrial fibrillation that is the most common cause of cardioembolic stroke.

Multi-channel blockers for treatment of atrial fibrillation: an effective strategy?

This editorial refers to ‘The new antiarrhythmic drug Vernakalant: ex vivo study of human atrial tissue from sinus rhythm and chronic atrial fibrillation’ by Wettwer et al ., pp. 145–154, this issue, and to ‘Atrial selectivity in Na+ channel blockade by acute amiodarone’ by Suzuki et al. pp. 136–144, this issue. Atrial fibrillation (AF) is the most common arrhythmia and one of the most vexing cardiovascular conditions for patients and the physicians who care for them. AF is a primary cause of cardioembolic stroke and may account for more than 20% of all stroke cases in older individuals.1 While AF can easily be diagnosed by electrocardiography, many cases of AF are undetected due to the lack of symptoms. Lifetime risk for developing AF after an age of 40 years is ∼25% for both men and women. The prevalence of AF has been increasing, due to both ageing of the population and an increased prevalence of risk factors such as obesity and sedentary lifestyle. The personal and societal economic consequences of AF are staggering. Given the scope of the problem, efforts to better diagnose and manage AF are urgently needed. Although many cardiovascular conditions (hypertension, heart failure, etc.) can be managed with drugs, pharmacotherapy for the management of AF remains inadequate. Many of the available antiarrhythmic drugs have the potential for life-threatening ventricular proarrhythmia, coupled with a limited efficacy in maintaining sinus rhythm. Other drugs have less proarrhythmia, but are associated with systemic toxicity when used for long periods. From this perspective, it seems clear that additional efforts to develop drugs that safely and effectively treat AF are urgently needed. To achieve this goal, fundamental studies are needed to better understand the pathophysiology of AF, to identify the differences between atrial and ventricular physiology, and then to selectively target the atrial …

Complications of stroke resulting from atrial fibrillation

Atrial fibrillation is the commonest cause of cardioembolic stroke, which accounts for approximately 20% of ischaemic stroke. Cardioembolic stroke has a higher risk of morbidity and mortality, resulting in greater disability, longer hospital stays, costlier rehabilitation, and complications that greatly affect the quality of life. Appropriate treatment with anticoagulants, in conjunction with the management of hypertension, diabetes and cholesterol, will reduce the risk of stroke. Complications of stroke include dysphagia, post-stroke seizures, dry mouth, depression and post-stroke pain. The treatment strategies involve medication, however this leads to polypharmacy which has can increases the risk of adverse drug reactions. Also, some patients are averse to taking multiple medications.

Chronic indeterminate phase of Chagas’ disease: mitochondrial involvement in infection with two strains

Chagasic cardiopathy has become one of the most frequent causes of heart failure and sudden death, as well as one of the most common causes of cardio-embolic stroke in Latin America. The myocyte response to oxidative stress involves the progression of cellular changes, primarily targeting the mitochondria and modifying therefore the energy supply. In this paper we analysed the effect of the infection of mice with 2 different strains of Trypanosoma cruzi (Tulahuen and SGO Z12) in the chronic indeterminate stage (75 days post-infection), upon the structure and function of cardiac mitochondria. The structural results showed that 83% of the mitochondria from the Tulahuen-infected mice presented an increase in their matrix and 91% of the mitochondria from the SGO Z12-infected group showed a reduction in their diameter (P < 0.05). When the Krebs cycle and mitochondrial respiratory chain functionality was analysed through the measurement of the citrate synthase and complexes I to IV activity, it showed that their activity was altered in all cases in a similar manner in both infected groups. In this paper we have demonstrated that the chronic indeterminate phase is not 'silent' and that cardiac mitochondria are clearly involved in the genesis and progression to the chronic chagasic cardiopathy when different factors alter the host-parasite equilibrium.

Novedades en la prevención secundaria del ictus cardioembólico

Non-valvular atrial fibrillation (NVAF) is the main cause of cardioembolic stroke. Classically, prevention consists of oral antivitamin-K anticoagulants (AVK), which, despite their demonstrated efficacy, continue to be underused due to their numerous drawbacks. Recently, a new generation of oral anticoagulants has been shown to have a better safety profile and greater efficacy than AVK. The studies that have compared rivoraxaban, dabigatran and apixaban with warfarin have also included a substantial proportion of patients who had previously had a stroke. The results of the substudies performed in this population with a high risk of hemorrhagic and embolic events have been consistent with those in the overall populations in these studies. The new anticoagulants are a feasible alternative to AVK in the secondary prevention of ictus in patients with NVAF. When anticoagulant therapy is contraindicated, percutaneous closure of the left atrial appendage could be an alternative.

Rare cause of cardioembolic stroke in former athlete with dilated cardiomyopathy

We present the case of a 50 year-old male, a former athlete with important cardiologic history who presented to our emergency department with sudden onset left side hemiparesis and dysarthria. The cerebral computed tomography showed a recent ischemic lesion in the right temporo-insular area and a spontaneously hyper-dense right middle cerebral artery. The Duplex ultrasound examination of the cervico-cerebral vessels showed significantly enlarged jugular veins, with intraluminal hyperechogenic images. The echocardiography showed severely dilated cardiac cavities, especially left atrium and auricle with many mobile hypoechogenic thrombi. The final diagnosis was cardioembolic stroke due to dilated cardiomyopathy. We chose to present this case in order to raise awareness of this low incidence diagnosis.

Thrombus through a patent foramen ovale: A direct cause of cardioembolic stroke and pulmonary embolism

Thrombus through a patent foramen ovale: A direct cause of cardioembolic stroke and pulmonary embolism

Thrombus through a patent foramen ovale: A direct cause of cardioembolic stroke and pulmonary embolism

We report the case of a 79-year-old man hospitalized for stroke. The patient had hypertension and dyslipidemia and the ECG revealed previously unknown atrial fibrillation. A transthoracic echocardiogram (TTE) was performed two days after admission to exclude an embolic source. This showed marked dilatation of the right cavities, systolic--diastolic flattening of the interventricular septum (IVS) (Figure 1, panel A) and depressed right ventricular systolic function (S′: 8 cm/s; 3D ejection fraction: 18%) (Figure 1, panel D; Video 1). The left ventricle was small and compressed by the bulging IVS; no other wall motion abnormalities were observed. There was a large thrombus 35 mm × 19 mm in size on the right atrium (RA) lateral wall (Figure 1, panel B), and another thrombus 40 mm in length through the patent foramen ovale (PFO) (Figure 1, panel C; Video 2). The patient underwent thoracic CT angiography that confirmed signs of chronic pulmonary embolism and assessed

Progress for Stroke Prevention With Atrial Fibrillation

Atrial fibrillation (AF) is both a common cardiac arrhythmia and a frequent cause of cardioembolic strokes. The prevalence of AF markedly increases with age and with the current population trends, the number of patients with AF is expected to continue to grow and may reach 12 million in the United States by 2050.1 AF accounts for up to 20% of all ischemic strokes and independently increases the risk of these events by up to 5-fold.2,3 Various cardiovascular risk factors do increase the risk of AF and given the continuing rise of obesity and resultant hypertension and diabetes, the future healthcare burden of AF-related strokes is likely to greatly increase. AF is arguably 1 of the best-studied causes of stroke with dozens of randomized trials that have led to well-established evidence-based recommendations regarding effective treatment modalities. Warfarin, a vitamin K antagonist, is currently the most commonly used oral anticoagulant. It has been used for decades, is inexpensive, and has standardized laboratory monitoring and reversal protocols. Warfarin is also exceedingly effective; a recent meta-analysis has shown it to reduce stroke by almost two thirds compared with placebo and to provide an almost 40% relative risk reduction compared with antiplatelet therapy.4 Warfarin, however, has several limitations that have led to underuse in the community. It has a very narrow therapeutic window with potentially life-threatening consequences from both under- and overdosing the medication. Bleeding, either systemically or intracranially, is the most feared complication; it has hindered a more wide-scale acceptance of this therapy, particularly among elderly patients. Maintaining most patients within that therapeutic window is challenging due to numerous drug and diet interactions and requires frequent and inconvenient blood testing and monitoring. Due to these difficulties, a portion of patients and physicians has never adequately adopted this therapy, which …

Progress for Stroke Prevention With Atrial Fibrillation

Atrial fibrillation (AF) is both a common cardiac arrhythmia and a frequent cause of cardioembolic strokes. The prevalence of AF markedly increases with age and with the current population trends, the number of patients with AF is expected to continue to grow and may reach 12 million in the United States by 2050.1 AF accounts for up to 20% of all ischemic strokes and independently increases the risk of these events by up to 5-fold.2,3 Various cardiovascular risk factors do increase the risk of AF and given the continuing rise of obesity and resultant hypertension and diabetes, the future healthcare burden of AF-related strokes is likely to greatly increase. AF is arguably 1 of the best-studied causes of stroke with dozens of randomized trials that have led to well-established evidence-based recommendations regarding effective treatment modalities. Warfarin, a vitamin K antagonist, is currently the most commonly used oral anticoagulant. It has been used for decades, is inexpensive, and has standardized laboratory monitoring and reversal protocols. Warfarin is also exceedingly effective; a recent meta-analysis has shown it to reduce stroke by almost two thirds compared with placebo and to provide an almost 40% relative risk reduction compared with antiplatelet therapy.4 Warfarin, however, has several limitations that have led to underuse in the community. It has a very narrow therapeutic window with potentially life-threatening consequences from both under- and overdosing the medication. Bleeding, either systemically or intracranially, is the most feared complication; it has hindered a more wide-scale acceptance of this therapy, particularly among elderly patients. Maintaining most patients within that therapeutic window is challenging due to numerous drug and diet interactions and requires frequent and inconvenient blood testing and monitoring. Due to these difficulties, a portion of patients and physicians has never adequately adopted this therapy, which …

Atrial fibrillation in pigs induces left atrial endocardial transcriptional remodelling

The leading cause of cardioembolic stroke is atrial fibrillation (AF), which predisposes to atrial thrombus formation. Although rheological alterations promote a hypercoagulable environment, as yet undefined factors contribute to thrombogenesis. The role of the endocardium has barely been explored. To approach this topic, rapid atrial pacing (RAP) was applied in four pigs to mimic AF. Left and right endocardial cells were isolated separately and their gene expression pattern was compared with that of four control pigs. The AF-characteristic rhythm disorders and endothelial nitric oxide synthase down-regulation were successfully reproduced, and validated RAP to mimic AF. A change was observed in the transcriptomic endocardial profile after RAP: the expression of 364 genes was significantly altered (p<0.01), 29 of them having passed the B>0 criteria. The left atrial endocardium [325 genes (7 genes, B>0)] was largely responsible for such alterations. Blood coagulation, blood vessel morphogenesis and inflammatory response are among the most significant altered functions, and help to explain the activation of coagulation observed after RAP: D-dimer, 0.49 (1.63) vs. 0.23 (0.24) mg/l [median (interquartile range)] in controls, p=0.02. Furthermore, three genes directly related to thrombotic processes were differentially expressed after RAP: FGL2 [fold change (FC)=0.85; p=0.007], APLP2 (FC=-0.47; p=0.005) and ADAMTS-18 (FC=-0.69; p=0.004). We demonstrate for the first time that AF induces a global expression change in the left atrial endocardium associated with an activation of blood coagulation. The nature of some of the altered functions and genes provides clues to identify new therapeutic targets.

Ablating Brain Embolism in Atrial Fibrillation

See related article, page 265. Atrial fibrillation (AF) is widely recognized as the most common cause of cardioembolic stroke in those aged >55 years. Less well appreciated are silent embolic infarcts and their impact on cognitive decline and vascular dementia. Hence, the prevention of both clinical and silent brain infarcts is the primary goal of effective AF treatment. Indeed, entire industries have been spawned to prevent stroke in AF. Warfarin is established as the benchmark stroke prevention treatment, although its risks and limitations are well known, not the least of which is underuse by …

Prevention of cardioembolic stroke.

Cardiac causes of ischemic stroke lead to severe neurological deficits from large intracranial artery occlusion compared to small vessel ischemic stroke. The most common cause of cardioembolic stroke is atrial fibrillation (AF), which has an increasing incidence with age. AF stroke trials demonstrate that anti-coagulation is superior to anti-platelet therapy in terms of ischemic stroke prevention. Recently, warfarin was compared with dabigatran, an oral, direct thrombin inhibitor, and was found to be at least equally effective in reducing ischemic stroke with less intracranial bleeding risk. Future research is investigating other direct thrombin inhibitors as potential alternatives to warfarin, which has a narrow therapeutic index, requires frequent blood monitoring, has multiple drug interactions, and a higher rate of intracranial bleeding. Other causes of cardioembolic stroke include myocardial infarction, left ventricular thrombus, reduced ejection fraction, valvular abnormalities, and endocarditis. Patent foramen ovale is a common finding on echocardiograms in patients with and without stroke (up to 20% of the population), and it is a controversial source of cryptogenic stroke. The best way to prevent cardioembolic stroke remains early detection and treatment of AF, and treating the underlying stroke mechanism. Cardiac magnetic resonance imaging is an emerging technology and reveals some sources of cardiac embolism missed by echocardiography, and might provide an additional diagnostic tool in investigating cardioembolic stroke.

Cardioembolic stroke: who is the guilty?

A young woman was referred following a transient ischemic attack due to suspect patent foramen ovale. At the diagnostic workup a spontaneous mild right-to-left atrial shunt owing to fenestrated aneurysmal septum was found. However, also a large arteriovenous malformation of the left lung was also imaged. At interventional cardiac catheterization, both malformations were closed using an Amplatzer Cribriform occluding device and a Amplatzer Vascular Plug II, respectively. In conclusion, patent foramen ovale is just one of the potential causes of cardioembolic stroke and a thorough diagnostic workup is mandatory after a cryptogenic stroke to rule out any additional source of paradoxical embolism.

Stroke Prevention in Atrial Fibrillation: Atrial Appendage Closure

The left atrial appendage (LAA) is the primary nonvalvular cause of cardioembolic stroke in patients with atrial fibrillation (AF). Warfarin and direct thrombin inhibitors such as dabigatran are presumed to prevent formation of LAA thrombus, and are first-line treatments to prevent ischemic stroke in AF. However, these medications carry many contraindications such as hemorrhage, and can interact with many drugs and supplements. Epicardial and endovascular techniques for occlusion of LAA are being explored, whether to mitigate the need for anticoagulation in patients at risk of bleeding or as a first-line therapy to reduce the risk of thromboembolic stroke. The purposes of this article are to 1) review the LAA structure and its potential contribution to ischemic stroke; 2) discuss the results of surgical and endovascular trials of LAA occlusion on risk of stroke and adverse events in AF patients; and 3) present early data on devices in development.

Antithrombotic medication for cardioembolic stroke prevention.

Embolism of cardiac origin accounts for about 20% of ischemic strokes. Nonvalvular atrial fibrillation is the most frequent cause of cardioembolic stroke. Approximately 1% of population is affected by atrial fibrillation, and its prevalence is growing with ageing in the modern world. Strokes due to cardioembolism are in general severe and prone to early recurrence and have a higher long-term risk of recurrence and mortality. Despite its enormous preventive potential, continuous oral anticoagulation is prescribed for less than half of patients with atrial fibrillation who have risk factors for cardioembolism and no contraindications for anticoagulation. Available evidence does not support routine immediate anticoagulation of acute cardioembolic stroke. Anticoagulation therapy's associated risk of hemorrhage and monitoring requirements have encouraged the investigation of alternative therapies for individuals with atrial fibrillation. New anticoagulants being tested for prevention of stroke are low-molecular-weight heparins (LMWH), unfractionated heparin, factor Xa inhibitors, or direct thrombin inhibitors like dabigatran etexilate and rivaroxaban. The later exhibit stable pharmacokinetics obviating the need for coagulation monitoring or dose titration, and they lack clinically significant food or drug interaction. Moreover, they offer another potential that includes fixed dosing, oral administration, and rapid onset of action. There are several concerns regarding potential harm, including an increased risk for hepatotoxicity, clinically significant bleeding, and acute coronary events. Therefore, additional trials and postmarketing surveillance will be needed.

Newly Diagnosed Atrial Fibrillation after Acute Ischemic Stroke and Transient Ischemic Attack: Importance of Immediate and Prolonged Continuous Cardiac Monitoring

Atrial fibrillation (AF) is the major cause of cardioembolic stroke. It often remains occult when asymptomatic and paroxysmal. We hypothesized that the detection of AF after acute ischemic stroke (AIS) or transient ischemic attack (TIA) could be improved by using continuous cardiac monitoring (CCM) immediately after admission. We sought to determine the detection rate of AF by immediate in-hospital CCM after cryptogenic and noncryptogenic AIS or TIA in patients without a previous diagnosis of AF. We retrospectively studied a cohort of 155 patients with cryptogenic and noncryptogenic AIS or TIA without known AF. We compared the detection rates of newly diagnosed AF (NDAF) in patients admitted to areas with CCM and those never admitted to these areas. We developed a multiple logistic regression model for identifying predictors of NDAF. We characterized NDAF episodes and analyzed how the availability of CCM data changed secondary prevention strategies. We detected NDAF in 21 patients (13.5%). Diagnostic rates of NDAF in patients who underwent CCM and those who did not undergo CCM were 18.2% and 2.2%, respectively (P = .005). The median time from admission to recognition of NDAF was 2.0 days. Most NDAFs were paroxysmal (95.2%) and lasted less than 1 hour (85.7%). Diabetes mellitus and infarct size were predictors of NDAF. Detection of NDAF prompted the initiation of anticoagulation therapy in 8.2% of the patients admitted to areas with CCM availability. Our findings suggest that immediate and prolonged CCM significantly improves the detection of NDAF after cryptogenic and noncryptogenic AIS or TIA, and that diabetes mellitus and infarct size are significantly associated with NDAF.

Cardiac Workup of Ischemic Stroke

Stroke is the leading cause of disability in developed countries and the third cause of mortality. Up to 15-30% of ischemic strokes are caused by cardiac sources of emboli being associated with poor prognosis and high index of fatal recurrence. In order to establish an adequate preventive strategy it is crucial to identify the cause of the embolism. After a complete diagnostic workup up to 30% of strokes remain with an undetermined cause, and most of them are attributed to an embolic mechanism suggesting a cardiac origin.There is no consensus in the extent and optimal approach of cardiac workup of ischemic stroke. Clinical features along with brain imaging and the study of the cerebral vessels with ultrasonography or MRI/CT based angiography can identify other causes or lead to think about a possible cardioembolic origin.Atrial fibrillation is the most common cause of cardioembolic stroke. Identification of occult atrial fibrillation is essential. Baseline ECG, serial ECG(’s), cardiac monitoring during the first 48 hours, and Holter monitoring have detection rates varying from 4 to 8% each separately. Extended cardiac monitoring with event loop recorders has shown higher rates of detection of paroxysmal atrial fibrillation.Cardiac imaging with echocardiography is necessary to identify structural sources of emboli. There is insufficient data to determine which is the optimal approach. Transthoracic echocardiography has an acceptable diagnostic yield in patients with heart disease but transesophageal echocardiography has a higher diagnostic yield and is necessary if no cardiac sources have been identified in patients with cryptogenic stroke with embolic mechanism.