Recurrent Embolic Events Research Articles

Use of Echocardiography in Detecting Cardiac Sources of Embolus

Up to 20% of all ischemic strokes are felt to be the result of emboli from the heart. High resolution transthoracic (TTE) and transesophageal (TEE) echocardiography have been the principal diagnostic tools for detecting associated cardiac abnormalities and for guiding medical and surgical approaches to these patients. In addition to identifying the precise location and morphological characteristics of intracardiac masses, echocardiography has improved our ability to predict embolic potential of these masses. Specific cardiac lesions that are predisposed to stroke and are readily identifiable by echocardiography include: cardiac thrombi, valvular vegetations, cardiac tumors, aortic atheroma, atrial septal aneurysm, and regional left ventricular wall abnormalities. Careful interrogation of patients with cerebrovascular accidents has identified a potential cardiac source of embolus in approximately 30%. This is largely due to the advent of TEE, which has provided much better assessment of posterior cardiac chambers including left atrium and left atrial appendage. Use of TEE in identifying a cardiac source of embolus is indicated in patients with stroke who are young, have no apparent cerebrovascular disease, or have recurrent embolic events. Echocardiography is an essential diagnostic tool in evaluating patients with a suspected cardiac source of embolus. TTE and TEE provide invaluable information regarding the majority of cardiac sources of embolus.

Clinical significance of antibodies against neutrophils in patients with inflammatory bowel disease and primary sclerosing cholangitis.

The presence of perinuclear antibodies against neutrophils (pANCA) has been detected recently in sera of patients with inflammatory bowel disease and primary sclerosing cholangitis. In order to evaluate their clinical significance, sera from 126 patients with inflammatory bowel disease (80 Crohn's disease and 46 ulcerative colitis and 22 patients with primary sclerosing cholangitis were examined for pANCA by indirect immunofluorescence on liver sections and cytocentrifuge slides of neutrophils and by immunoblot. Perinuclear antibodies against neutrophils were found in 83% of patients with ulcerative colitis in 88% of patients with primary sclerosing cholangitis and inflammatory bowel disease, in 40% of patients with primary sclerosing cholangitis but without inflammatory bowel disease, and in 25% of patients with Crohn's disease using the immunofluorescence test. Titres of pANCA ranged from 1:10 to 1:1000 in ulcerative colitis and primary sclerosing cholangitis (median 1:100), whereas in Crohn's disease only four patients had titres of more than 1:10. The occurrence of pANCA did not correlate with clinical activity of Crohn's disease and primary sclerosing cholangitis whereas in ulcerative colitis high titres of pANCA were found mainly in active disease. Using an immunoblot system with sonified neutrophils as antigen, 82% of sera from patients with primary sclerosing cholangitis reacted with up to five different determinants, whereas only 12% of sera from patients with Crohn's disease and 11% of sera with ulcerative colitis detected one of the determinants, suggesting different antigens involved in pANCA reaction.

Identification of aortic thrombus by magnetic resonance imaging

The unique properties of magnetic resonance imaging result in the potential to differentiate various components of the diseased arterial wall. In this article four cases are presented in which magnetic resonance imaging showed mural aortic thrombus and its anatomic relationship to the visceral and renal arteries. Once thrombus is identified and localized specific operative strategies can be undertaken to prevent recurrent embolic events and/or avoid perioperative thromboembolic complications.

Anticoagulation and hemorrhagic infarction in cerebral embolism secondary to rheumatic heart disease.

The immediate clinical course of 42 patients with cerebral embolism secondary to rheumatic heart disease (RHD) was analyzed retrospectively. All the cases included cranial computed tomographic (CT) findings. Twenty-five patients received early anticoagulant therapy (AT) and 17 did not. Recurrent embolic events occurred in only one case. Seven instances of hemorrhagic infarction (HI) were found. In five cases, the development of HI correlated with a recurrent stroke, which occurred in each case within 48 hours after the initial cerebral embolism. Three of the patients with HI died (all of them were receiving AT). We believe that HI is a frequent cause of recurrent stroke after a cerebral embolic event, that it generally occurs in the first 48 hours, and that its outcome is possibly worsened by AT. Anticoagulant therapy should be delayed for three days after a cerebral embolic event secondary to RHD.

Recurrent systemic embolic events with valve prosthesis.

Among 1436 patients who underwent valve replacement, the 400 first cases were studied to assess the features of recurrent systemic embolic event. The mean follow-up was 87 months. Three groups of patients were compared: groups A-289 patients without any thromboembolic event (72.25%); group B-78 patients with only one embolic event (19.5%); group C-33 patients with several embolic events (8.25%). The frequency of recurrence was high: one patient out of three (linearized mean 8.9% in group C considering only one recurrence, vs 3.8% in group B). The recurrence have the same location in 45% of patients. The consequences of these embolisms are serious; each event has a 30 to 40% risk of death or major disability. Four variables seem statistically to promote the occurrence of embolic events: mitral prostheses, pre-operative fibrillation, left atrial enlargement, poor anticoagulant therapy. 54 months after the first embolic event, 60% of the patients with poor anticoagulant therapy experience a recurrent thromboembolism vs 20% with adequate therapy. Twenty-six patients of groups B and C had a pathological study of prostheses. Thrombosis of the prostheses was found in 12 out of 18 patients in group B and in 7 out of 8 patients; in group C. Strict observance of anticoagulant therapy is the better way to prevent thromboembolism and especially recurrences. A reoperation is sometimes necessary. Valve re-replacement was performed in 27 cases out of 1436 patients.