Left ventricular assist device (LVAD) is essential for patients with severe heart failure, but there is a risk of thrombus formation on the aortic root and cusps, leading to coronary artery occlusion. Even with the narrowing of the echo-window due to LVAD, careful observation of coronary flow by transthoracic echocardiography can evaluate the patency of coronary flow non-invasively and immediately.