Extracranial carotid artery disease in patients with arterial limb embolism.

Letters to the Editor will be published, if suitable, as space permits. They should not exceed 1,000 words (typed double-spaced) in length and may be subject to editing or abridgment. To the Editor: The relationship between embolism and thrombosis as a cause of ischemic stroke is far from established. Not all ischemic strokes in patients with a cardiac source are caused by cardio-genic embolism since cerebrovascular atherosclerosis often coex-ists. Thus, the clinical differentiation between thrombotic and embolic infarction is extremely difficult and often impossible. General hallmarks of cerebral embolic events have been outlined , with the presence of atherosclerotic lesions in the appropriate artery considered by most as a feature excluding cerebral embolism. 1-3 However, atherosclerotic lesions of the cervical carotid arteries have been found in 23 of 100 asymptomatic men aged 50-69 years, 4 in 34 of 108 patients with familial hypercholesterolemia and coronary artery disease, 3 and in 21 of 56 elderly adults with isolated systolic hypertension. 6 Furthermore, in two different studies, the concomitance of appropriate carotid disease and potential cardiac sources of emboli illustrates the difficulties of diagnosing cardioembolism in an individual patient. In one study, 7 the appearance together of arterial disease and potential cardiac sources of emboli was evaluated in 205 patients with transient ischemic attacks (TIAs) who underwent both angiog-raphy and echocardiography. Fifty patients had a potential source of emboli, and a carotid lesion appropriate to the TIAs was present in 38 of these 50 patients. In the work by Rem et al, 8 in which 184 consecutive patients with TIA and stroke were studied, 59 patients with a possible cardiac source for cerebral emboli were detected. After cerebral angiography, 29 of these 59 patients also showed a vascular lesion in the appropriate carotid artery. The authors could not decide definitely which lesion was responsible for the cerebral embolus. Since carotid atherosclerosis is so frequent in different populations , we must ask what is its frequency in patients with demonstrated cardioembolic emboli? We screened 25 consecutive patients without history of stroke admitted because of an acute arterial limb embolism for atherosclerotic lesions of the cervical carotid arteries using a high-resolution multi-gated pulsed Doppler system. There were nine men and 16 women aged 53-87 (mean 68) years. The anatomic site of lodgement of the arterial embolus was femoral in 10 patients, popliteal in five, upper extremity in five, aortic saddle in three, and iliac …