Potential Cardiac Source Of Embolism Research Articles

Epidemiological characteristics of lacunar infarcts in a population.

This study evaluated the characteristics and natural history of patients with lacunar (small, deep) cerebral infarcts in a defined population for comparison of these characteristics to those in patients with nonlacunar infarcts. This is a population-based study in Rochester, Minnesota, from 1960 to 1984, that used the medical record-linkage system to identify and characterize patients with cerebral infarction. The age- and sex-adjusted average annual incidence rate of lacunar cerebral infarction was 13.4/100,000 persons, accounting for 12% of all first cerebral infarcts. Temporal trends in incidence rates, stroke recurrence rates, prevalence of diabetes mellitus, and causes of death (given survival for 30 days) for cases of lacunar infarction were not significantly different from those for cases of nonlacunar infarction. Hypertension was found in 81% of patients who had a lacunar infarct and in 70% of patients who had a nonlacunar infarct (p = 0.05). A potential cardiac source of embolism was found in 12% of patients who had a lacunar infarct and in 28% of patients who had a nonlacunar infarct (p = 0.002). Survival was significantly better after a lacunar infarct than after a nonlacunar infarct. Small, deep cerebral infarcts had many of the epidemiological characteristics of other cerebral infarcts but there was a slightly higher frequency of hypertension, significantly lower frequency of a cardiac embolic source, and significantly better survival in patients with lacunar infarction than in those with nonlacunar infarction.

Double infarction in one cerebral hemisphere

Thirty-two patients whose first stroke was due to double infarct in one cerebral hemisphere were identified among 1,911 consecutive patients from the Lausanne Stroke Registry. The double infarct involved territories of the superficial middle cerebral artery, superficial posterior cerebral artery, lenticulostriate, anterior choroidal artery, or borderzone. The most common combination involved territories of the anterior middle cerebral artery plus the posterior middle cerebral artery. In the patients with the double infarct, the prevalence of potential cardiac sources of embolism (19%) was similar to that found in the registry in general, but the double infarct was closely associated with tight (greater than or equal to 90% of the lumen diameter) stenosis or occlusion (75%) of the internal carotid artery. The most common neurological picture mimicked large infarction in the middle cerebral artery territory, but nearly half of the patients with double infarct in one cerebral hemisphere had a specific clinical syndrome, which was not found in the 1,879 remaining patients from the registry, including hemianopia-hemiplegia (in 6), acute conduction aphasia-hemiparesis (in 2), and acute transcortical mixed aphasia (in 6), in relation to characteristic combinations of infarcts. These unique clinical and etiological correlates warrant the recognition of double infarct in one cerebral hemisphere from other acute ischemic strokes.

Transesophageal echocardiography in the detection of potential cardiac source of embolism in stroke patients.

To compare the diagnostic yields of transesophageal and transthoracic echocardiography in the detection of potential cardiac sources of embolism, 63 patients (mean +/- SD age 63 +/- 15 [range 18-87] years) with transient ischemic attacks or stroke underwent both procedures. Transthoracic echocardiography revealed a potential cardiac source of embolism in 14% (nine) of the patients, all of whom had clinical evidence of heart disease. Transesophageal echocardiography revealed a potential cardiac source of embolism in 41% (26) of the patients; 27% (seven) of these patients had no clinical cardiovascular abnormalities. Abnormalities detected only by transesophageal echocardiography in the patients with unsuspected cardiac disease included atrial septal aneurysm in two, patent foramen ovale in two, left atrial appendage thrombus in one, and myxomatous mitral valve in two. The 26 patients with an identified cardiac source of embolism were older (67.5 versus 59.4 years, p = 0.04), more frequently in atrial fibrillation (62% [16] versus 8% [3], p less than 0.0001), had a larger left atrium (43 versus 37 mm, p = 0.01) and more commonly had left ventricular hypertrophy (62% [16] versus 32% [12], p less than 0.02) than the 37 patients in whom no cardiac source of embolism was identified. Thus, transesophageal echocardiography is more sensitive than transthoracic echocardiography in the detection of potential cardiac sources of embolism in patients with cerebral ischemic events.

Cardiac sources of embolism and cerebral infarction—clinical consequences and vascular concomitants

We studied clinical characteristics and coexisting causes of stroke in 305 patients admitted to a population-based primary care center with an initial ischemic stroke and a potential cardiac source of embolism (PCSE). Using systematic standardized cardiac, arterial, and cerebral investigations and the logistics of the prospective Lausanne Stroke Registry, we found that nonprogressive onset, hemianopia without hemiparesis or hemisensory disturbances, Wernicke's aphasia, ideomotor apraxia, involvement of specific territories (posterior division of middle cerebral artery, anterior cerebral artery, cerebellum, multiple territories), and a hemorrhagic component were associated with the presence of a PCSE, as compared with 1,006 initial ischemic stroke patients without PCSE. Although age and sex did not differ, the frequency of hypertension, diabetes, cigarette smoking, elevated blood cholesterol, and deep hemispheric or brainstem infarcts was higher in the patients without a PCSE. Nearly one-fourth of the patients with a PCSE had a coexisting potential arterial cause of stroke (large artery greater than or equal to 50% stenosis or small-vessel disease). In the majority of patients with a PCSE (76.7%), cardioembolism was the most likely cause of stroke, although a direct source of embolism was uncommon (4.3%) and intracranial embolic occlusions were present in less than one-half of the patients who were angiographed.

Early spontaneous hematoma in cerebral infarct

We identified 15 patients (63 +/- 8 years) in whom CT showed no bleeding within 6 hours of stroke onset but showed ganglionic or lobar hemorrhage less than 18 hours later, without visible underlying infarct (early spontaneous intra-infarct hematoma [ESIH]). No patient had antithrombotic therapy or a coagulation disorder, but eight had hypertension. The second CT was prompted by rapid worsening (in 10) or because the first CT was not available (in five). Prior transient ischemic attacks, silent infarcts on CT, and a potential cardiac source of embolism were more common in patients with ESIH than in 200 patients with primary cerebral hemorrhage (PCH) admitted during the same period. Distal occlusions were present in four of five patients who underwent intracranial studies within the first 2 days. Most of these patients probably had embolism with early and extensive bleeding in the ischemic area. Our findings suggest that ESIH may be under-recognized, while PCH may be overdiagnosed.

Superiority of transesophageal echocardiography in detecting cardiac source of embolism in patients with cerebral ischemia of uncertain etiology

The diagnostic yield of transesophageal and transthoracic echocardiography for identifying a cardiac source of embolism was compared in 79 patients presenting with unexplained stroke or transient ischemic attack. There were 35 men and 44 women with a mean age of 59 years (range 17 to 84); 52% had clinical cardiac disease. Both transthoracic and transesophageal echocardiograms were performed using Doppler color flow and contrast imaging.Transesophageal echocardiography identified a potential cardiac source of embolism in 57% of the overall study group compared with only 15% by transthoracic echocardiography (p < 0.0005). Compared with transthoracic echocardiography, transesophageal echocardiography more frequently identified atrial septal aneurysm associated with a patent foramen ovale (9 versus 1 of 79 patients, p < 0.005), left atrial thrombus or tumor (6 versus 0 of 79 patients, p < 0.05) and left atrial spontaneous contrast (13 versus 0 of 79 patients, p < 0.0005). All cases of left atrial thrombus or spontaneous contrast were identified in patients with clinically identified cardiac disease.In the 38 patients with no cardiac disease, transesophageal echocardiography identified isolated atrial septal aneurysm and alrial septal aneurysm with a patent foramen ovale more frequently than transthoracic echocardiography (8 versus 2 of 38 patients, p < 0.05). The two techniques had a similar rate of identifying apical thrombus and mitral valve prolapse. Overall, transesophageal echocardiography identified abnormalities in 39% of patients with no cardiac disease versus 19% for transthoracic echocardiography (p < 0.005).Thus, transesophageal echocardiography identifies potential cardiac sources of embolism in the majority of patients presenting with unexplained stroke. Even in patients with no clinical heart disease the diagnostic yield of transesophageal echocardiography is 39%. The use of transesophageal echocardiography in patients with unexplained stroke, even in those with a normal transthoracic echocardiogram, should be recommended.

Intracranial Large-Artery Disease and 'Lacunar' Infarction

Small ''lacunar'' infarcts in the territory of the deep perforators (ITDP) have usually been attributed to small-vessel disease associated with hypertension or diabetes, but recently also to embolism from extracranial large-artery atherosclerosis or heart disease. However, in several cases, the cause of ITDP remains undetermined. Of 1,800 patients with first-ever stroke from the Lausanne Stroke Registry, 320 had ITDP smaller than 1.5 cm on computed tomography or magnetic resonance imaging. In 26 (8%) of them, the etiology of ITDP remained undetermined, because they had no hypertension, diabetes, extracranial large-artery disease or a potential cardiac source of embolism. Angiography was performed prospectively in the last 16 patients with undetermined etiology for ITDP. In 10 of them, intracranial stenosis on the parent large artery (middle cerebral artery in 6, basilar artery in 4) was demonstrated at the presumed site of origin of the deep perforator. Local obstruction of the mouth of deep perforators by intracranial large-artery disease may not be an uncommon cause of ITPD and should be looked for in ITDP of ''undetermined'' origin.

Improved morphologic characterization of atrial septal aneurysm by transesophageal echocardiography: Relation to cerebrovascular events

Transthoracic and transesophageal echocardiography was performed in 23 consecutive adult patients with an atrial septal aneurysm. In three patients with a cerebrovascular event the diagnosis was established by the transesophageal approach only. Interatrial shunting on transthoracic imaging with use of echocardiographic contrast imaging or Doppler color mapping, or both, was detected in 7 (41%) of 17 patients. On performing contrast imaging in combination with color flow mapping during transesophageal echocardiography, positive shunting was demonstrated in 15 (83%) of 18 patients. Echocardiographic identification of multiple fenestrations (n = 4) and thrombus within the aneurysm (n = 2) could be achieved for the first time by transesophageal ultrasound application. Cerebrovascular events occurred in 12 (52%) of 23 patients and were regarded as being definitely thromboembolic in 10 (43%); 8 (67%) of the 12 patients had repeated cerebral events. Except for mitral valve prolapse in one patient, no other potential cardiac source of embolism could be identified despite the use of transesophageal echocardiography. A thickening of the aneurysmal membrane greater than or equal to 5 mm was found in 9 (75%) of 12 patients with versus 3 (27%) of 11 patients without a cerebrovascular event (p less than 0.05); this proved to be the only significant difference between the two patient groups. The mechanism of embolization may be both primary thrombus formation within the aneurysm and paradoxic embolization through an interatrial communication as demonstrated by the findings in two patients. It is concluded that atrial septal aneurysm is a cardiac abnormality with thromboembolic potential. In patients with this lesion and a history of an embolic event, long-term anticoagulant therapy is indicated.

Femoral Embolectomy for Embolic Lower Limb Ischemia: Influence of Coexisting Atherosclerotic Occlusive Disease

The authors studied the results after embolectomy performed in patients admitted with a diagnosis of acute embolic lower limb ischemia. All patients had a potential cardiac source of emboli. The results were retrospectively analyzed in two groups of patients: those with and those without atherosclerotic occlusive disease in the femoral artery. Gangrene was uncommon and the mortal ity rate was low (10%) in patients without occlusive disease, whereas postopera tive gangrene with or without death of the patient was common (37%) and the mortality rate was high (34%) in patients with occlusive disease. Embolectomy performed within twelve hours from onset of symptoms was more often success ful than embolectomy performed later in patients without, but not in those with, occlusive disease. Reoperations, as well as bleeding complications in anticoagu lated patients, were more frequent in the latter patients. This study indicates that patients with peripheral atherosclerotic occlusive disease constitute a signif icant risk group for morbidity and mortality after embolectomy. It is suggested that occlusive disease should be actively searched for when a patient with acute lower limb ischemia is admitted and also when the acute ischemia is judged on clinical grounds to be of embolic origin.

Middle cerebral artery pial territory infarcts: a study of the Lausanne Stroke Registry.

Using a standard protocol (Doppler ultrasonography, electrocardiography, brain computed tomography, and in selected cases angiography, echocardiography, and Holter monitoring) we studied the clinical characteristics and etiological factors in 380 patients with first stroke who had a corresponding infarct limited to the territory of the pial branches of the middle cerebral artery (MCA) on computed tomography. The presumed cause of infarction was large-artery disease (greater than or equal to 50% carotid artery or MCA stenosis or occlusion) in one-third of the patients and cardioembolism in one-fourth of the patients. Half of 230 patients undergoing angiography showed evidence for distal occlusions suggesting artery-to-artery or cardiac emboli. Severe heart disease and potential cardiac sources of embolism were more common in patients with infarcts in the territory of the posterior (inferior) division of MCA than in patients with infarcts in the territory of the anterior (superior) division of MCA. Persisting functional disability on discharge was also more severe in patients with the former than in patients with the latter. The neurological picture was polymorphous and it could sometimes even be misleading, as in some patients with a classical lacunar syndrome or with aphasia and unexpected sparing of speech areas. However, a few clinical syndromes apparently specific for involvement of a single MCA branch could be delineated, and in some instances they were highly predictive of embolism from heart or proximal artery.

Anterior choroidal artery territory infarction: a small vessel disease.

To investigate the cause(s) of infarction in the anterior choroidal artery territory, we studied 31 patients (18 men, 13 women) aged 19-82 (mean 58) years, with infarction in this territory documented by computed tomography. All patients were evaluated within 30 days after infarction and had carotid artery studies (arteriography in 17, duplex ultrasound in 14). Fifteen patients had echocardiography. Risk factors for atherosclerosis were chronic hypertension in 20 patients, smoking in 17, diabetes in 10, age greater than 69 years in eight, and elevated serum cholesterol concentration in three. The percentage of patients with extracranial carotid artery stenosis (four of 31, 13%) and the severity of stenosis (mild in two, moderate in two) were similar to that reported in neurologically asymptomatic individuals. The percentage of patients with intracranial carotid artery stenosis (one of 17, 6%) or potential cardiac sources of emboli (two of 31, 6%) was also low. Our findings suggest that infarctions in the anterior choroidal artery territory usually result from small-vessel disease. Associated carotid artery stenosis and potential sources of cardiac emboli are rare and may be coincidental.

Cardiac and arterial lesions in carotid transient ischemic attacks.

Two hundred fifty consecutive patients with carotid transient ischemic attacks (TIAs) and no previous stroke were assessed with cerebral angiography (95%), two-dimensional echocardiography (86%), electrocardiography (100%), and Holter monitoring (99 selected patients). Angiography disclosed a lesion appropriate to the TIAs in 84%. Lesions also occurred in the asymptomatic carotid artery, but stenosis of more than 75% of the lumen diameter and ulcers were significantly more frequent on the symptomatic side. Twenty-three percent of the patients had a potential source of emboli from the heart, usually in the context of symptomatic heart disease. Among the 205 patients who underwent full angiographic and cardiac investigations, 6% had an isolated potential cardiac source of emboli and 19% had a potential cardiac source of emboli associated with appropriate carotid disease. The search for a potential cardiac source of emboli is strongly indicated in patients with carotid TIAs and known heart disease. In the patients with no history of heart disease, the yield of this search is low, but our results suggest that at least 14 of such patients have an undetected potential cardiac source of emboli. Cardiac and arterial lesions commonly coexist in carotid TIAs.

Frequency of echocardiographic abnormalities in patients with ischemia of the carotid territory--a preliminary report.

Eighty-eight consecutive patients referred to a neurosurgical Department (63 men and 25 women) aged from 14 to 68 years, with cerebral ischemia in the carotid territory were subjected to M-mode and two-dimensional echocardiography, carotid angiography and assessment of risk factors. There were 27 patients (average age 54 years) in whom carotid angiography demonstrated a probable source for the ischemia. Carotid angiography was normal in 51 of the remaining 61 (average age 39 years) while 10 revealed distant emboli. Although the incidence of "abnormal echocardiograms" was similar in the two groups (56% and 54% respectively) the spectrum of abnormalities were different. Only 5 (18%) of the 27 patients with abnormal angiograms had a potential cardiac source of emboli while 24 (39%) out of the remaining 61 patients had a potential cardiac source demonstrated at echocardiography. There was a high incidence of mitral valve prolapse (34%) in this latter group of patients. Mitral valve prolapse was not seen in the present series in patients with a probable carotid source on angiography.

Clinical utility and management impact of M-mode echocardiography

To determine the clinical utility and management impact of M-mode echocardiography, 182 echocardiograms were analyzed at a university teaching hospital. The physicians who ordered the echocardiograms said that 12 percent provided crucial information that was not available from other tests and that 26 percent resulted in a change in patient management. According to two independent board-certified cardiologist-reviewers, 86 percent of echocardiograms were appropriately ordered, but only 15 echocardiograms (8 percent) were actually needed for a change to a new and appropriate management. According to the reviewers, the 77 Group I M-mode echocardiograms (those ordered to evaluate left ventricular function, left atrial size, potential cardiac sources of emboli, or the possibility of bacterial endocarditis, or those ordered in patients who, according to the ordering physician, had undergone or would undergo catheterization regardless of the results of echocardiography) were less likely than the 105 Group II M-mode echocardiograms (those ordered to evaluate possible mitral valve prolapse, hypertrophie cardiomyopathy, valvular function, or the pericardium) to be ordered appropriately, to provide helpful information, or to provide crucial results. Group I echocardiograms had reviewer-assessed appropriate management impact in only one case (1 percent) compared with a 13 percent rate of management impact for Group II M-mode echocardiograms (p < 0.01). Although echocardiography can be accurate and valuable with yields similar to those of other noninvasive procedures, 77 (42 percent) of 182 M-mode echocardiograms in this hospital could be predicted at the time of ordering to be in a low-yield group.