YOSHIKAWA MEMORIAL LECTURE「Echocardiography in Stroke Patients」
座長 渡辺 弘之（東京ベイ・浦安市川医療センター 循環器内科）
演者 Shunichi Homma（Columbia University)
Transthoracic (TT) and transesophageal echocardiography (TE) play major roleS in diagnosing potential embolic causes in patients with ischemic stroke. Intracardiac thrombus can be detected by TT echocardiography. Dilated cardiomyopathy is a well recognized source of cardiac embolism. Valvular vegetations are also findings associated with cerebral embolization. Size of vegetation is important in determining the risk of embolization. Left atrial dimension is related to stroke risk and can be related to silent brain infarction. Using TE echocardiography, myocardial abscess and vegetations are detected at a significantly higher rate than with TT echocardiography. Vegetations associated with prosthetic valves are much better diagnosed with the use of TE echocardiography. Importantly, left atrial appendage thrombus is not detectable without the use of TE echocardiography. New antithrombotic agents are more routinely used for patients with atrial fibrillation (AF). In some cases, appendage closure device is used in patients with AF who can not be anticoagulated. Large tumors, such as myxoma, are easily detected with TT method but small tumors and vegetations are detectable only with the use of TE echocardiography. Patent foramen ovale (PFO), a communication between the right and left atrium present in over 25% of normal population has been associated with stroke. In addition to medical therapy, closure devices are being investigated to prevent recurrent stroke. Aortic arch plaque is independently associated with stroke. In transcatheter aortic valve replacement (TAVR), since the technique requires manipulation of heavily calcified aortic valve, morphology of the valve and plaques in proximal ascending aorta may relate to the occurrence of stroke. Left ventricular assist device (LVAD) typically has a flow intake port located in left ventricular apex. Thrombus may form that could lead to embolization that may be detected with echocardiography.