Techniques for comprehensive two dimensional echocardiographic assessment of left ventricular systolic function

摘要

The quantitation of left ventricle (LV) volumes and ejection fraction is an important aspect of cardiac evaluation in all cardiac disorders. Prognosis in many types of heart disease is closely related to global left ventricular ejection fraction (LVEF), falling off rapidly as the ejection fraction falls below 40% (fig 1). However, although ejection fraction has the advantage of being a simple numerical parameter that reflects LV function, it is strongly influenced by loading conditions and docs not correlate well with symptom status. Perhaps more importantly, although two dimensional (2D) ejection fraction is meaningful when applied across populations or to stratify risk in individuals, its value as a sequential test within individuals is constrained by limited test-retest reliability.