Echocardiography has been one of the most significant advances in cardiology in the past two decades. It can provide anatomic, functional hemodynamic, and blood flow information. Conventional transtho racic echocardiography has limitations, particularly in certain patients such as those with obesity, chronic lung disease, or chest wall defor mity, or in those where a transthoracic approach is difficult for reasons including trauma, life support apparat uses, and surgical dressings. There are also certain disease states or conditions in which transtho racic echocardiography expectedly gives...