Echocardiography Techniques III Exam 1 Practice

Left atrial enlargement reflects chronically increased left-sided filling pressures and volume load, and the most common source of that pressure overload is mitral valve disease. When the mitral valve leaks (mitral regurgitation) or narrows (mitral stenosis), blood either backloads into the left atrium or the atrium bears the higher pressure needed to push blood through the stiff valve. Over time, the left atrium enlarges to accommodate this excess volume or pressure, which is why mitral valve pathology is the classic association. Right-sided heart disease typically enlarges the right atrium, not the left. Isolated left ventricular non-compaction is a ventricular abnormality that can affect overall heart function and may secondarily influence atrial size, but it does not classically produce left atrial enlargement as readily as mitral valve disease. Pulmonary hypertension without left heart disease does not primarily cause left atrial enlargement since the pressure overload is on the pulmonary vasculature and right heart, not the left atrium.