long-axis can review the lv outflow tract, lv at the base, and lv at the midsection. structures visible: aortic valve in short-axis aortic valve dysfunction, aortic sclerosis/stenosis tricuspid valve in long-axis pulmonary valve in long-axis right ventricle, including inflow and outflow tracts left ventricle in short-axis closer to the base can reveal the left ventricular outflow tract at the level of the base can show the movement of the mitral valve leaflets in short-axis at the level of mid-lv can show papillary muscles measurements in this view can be used to quantify the heart: aortic valve area by planimetry color doppler of all four valves spectral doppler of tricuspid and pulmonary valves apical four chamber (a4c) apical 4 chamber this view is obtained at the apex of the heart and looking toward the base of the heart (where the valves are). in this view, the mitral valve, tricuspid valve, and all four chambers are visible. this view shows the right ventricle from base to apex and is a useful view to estimate rv systolic function. tapse (= tricuspid annular plane systolic excursion) is also measured in this view with m-mode through the lateral tricuspid annulus. structures: inferior septum and anterior lateral segments of the left ventricle right ventricle left atrium right atrium mitral valve tricuspid valve measurements in this view can be used to quantify the heart: rv size and function; tapse left atrial size right atrial size mitral valve flow is best seen in this view and has the best angle with probe to estimate flows tricuspid valve flow tissue doppler at the mitral valve annulus (septum and lateral wall) for diastolic function agitated saline bubble study for right to left shunting (pfo, asd, vsd) with contrast, apical and mural lv thrombi can be easily seen apical three chamber (a3c) this view is obtained at the same window as the apical four chamber and then rotation of the probe. in this view, the mitral valve and aortic valve are in view and is roughly similar to the parasternal long axis. in this view, the lv outflow tract is best in alignment with the probe and so gives the best estimate of flow through the lvot, which is commonly used to estimate aortic stenosis. structures: aortic valve mitral valve left ventricle left atrium measurements in this view can be used to quantify the heart: left ventricular outflow tract volume-time integral (lvot vti) to be used in conjunction with aortic valve vti for aortic valve area and stenosis mitral valve flow apical two chamber (a2c) apical two chamber this view is obtained at the same window as the apical four chamber and then rotation of the probe. in this view, the mitral valve is visible with the left atrium and left ventricle. structures: anterior and inferior segments of the left ventricle mitral valve in long-axis left atrium measurements in this view can be used to quantify the heart: mitral valve flow spectral doppler of the mitral valve subcostal subcostal this view is obtained below the sternum and at the top part of the abdomen. in this view, the junction of the inferior vena cava with the right atrium is best seen. from this window, it is possible in some people to see roughly equivalent views of the apical four chamber and parasternal short views. in some people, this may afford these common views but at a subcostal window that may not be obtained through the parasternal and/or apical windows because of various reasons such as chest wall trauma, open wounds, or poor acoustic windows. however, the subcostal window is the only window to view the inferior vena cava that can help support an estimation of the central venous pressure based on size and collapsibility during respiration. other non-cardiac structures are visible in this view and some pathologies — such as ascites — can be observed. suprasternal (ssn) this view is obtained above the sternum in the suprasternal notch. in this view, the aortic arch and portion of the descending aorta can be seen. color and spectral doppler through the descending aorta can show signs of coarctation of the aorta. structures examples of tte views of various structures of the heart. aortic valve psax measurements example of quantification of the aortic root routine tte exams can provide a significant wealth of information about the heart's structure and function: left ventricular size, thickness, systolic function, and diastolic function right ventricular size and systolic function aortic valve aortic valve sclerosis & stenosis aortic valve insufficiency mitral valve mitral stenosis mitral regurgitation tricuspid valve tricuspid regurgitation (stenosis is possible, but rare) pulmonary valve pulmonary regurgitation (stenosis is possible, but rare) inferior vena cava size as estimate of central venous pressure aortic root size for thoracic ascending aortic aneurysm pericardial effusion size all function dysfunction is graded on a scale (normal, trace, mild, moderate, or severe) based on various criteria. grading of valve function is used for prognosis and helps determine management as valve dysfunction progresses. echo societies have published normal ranges for various features of the heart on various views to promote tte as a quantifiable assessment of the heart. equations quantitative echo utilizes a number of equations to calculate aspects of the heart structure and function. simplified bernoulli equation and continuity equation are two common equations used. others are used in grading valve function (e.g., eroa, pisa). diseases tte can be useful for diagnosing many cardiac diseases. cardiomyopathy: dilated, restrictive, and hypertrophic pulmonary hypertension (requires some degree of tricuspid regurgitation) septal defects including asd & vsd stenosis and regurgitation/insufficiency of valves structure and function of prosthetic valves thoracic ascending aortic aneurysm infiltrative diseases such as amyloidosis cardiac tamponade (although a clinical diagnosis, it can suggest subclinical diagnosis) evaluation of congenital diseases (e.g., tetralogy of fallot, transposition) pulmonary embolism endocarditis (sensitivity is higher with tee)