ABSTRACT
Warren J. Manning Department of Medicine, Cardiovascular Division, Harvard Medical School, and Beth Israel Deaconess Medical Center, Boston, Massachusetts, U.S.A.
Cardiac sources of cerebrovascular ischemic events are increasingly being recognized and
may account for 20-30% of the 500,000 strokes that occur annually in the United States
(1). Conventional transthoracic echocardiography (TTE) remains the cornerstone of
noninvasive cardiac imaging and has been extensively used in numerous studies during
the past three decades to identify both clinical and imaging risk factors for cardiogenic
thromboembolism. Subsequently, moderately invasive transesophageal echocardiography
(TEE) has been shown to be a superior method for the identification of most cardiac
sources of emboli (2,3) and to be more cost effective (4). Clinical paradigms for the use
of these primary imaging modalities continue to evolve. In addition, preliminary data
suggest that newer imaging methods, such as magnetic resonance imaging (MRI), may
also have an important role in identifying cardiogenic sources of embolism, but the
impact of these newer imaging methods on treatment and prognosis remains to be defined.
MAJOR SOURCES OF EMBOLI
