IS THERE A HEMISPHERIC SIDE PREFERENCE OF CARDIAC VALVULAR EMBOLI

Microaggregates arising from prosthetic cardiac valves offer the oppor tunity to examine the distribution of valvular emboli in the human cer ebral circulation. Forty-four patients with different kinds of prosthe tic valves underwent bilateral transcranial Doppler monitoring for 1 h to detect high intensity Doppler signals representing microemboli. Co mparing the total number of embolic signals in both middle cerebral ar teries (N = 1066), a side preference was not statistically evident. Ho wever, clear side preferences were obvious in some individuals. The la ck of statistical evidence for hemispherical preferences of cardiac mi croembolism in general does not exclude selective streaming in individ uals, explaining the clinical observation of lodging preferences of re current cardiac embolism. A cardiac source of microembolism may mimic disease activity of extracranial carotid artery stenosis and bias the localization of embolic source.