October 31, 2003Open Access
Techniques for comprehensive two dimensional echocardiographic assessment of left ventricular systolic function
Key Result
Two-dimensional echocardiography for calculating left ventricular volumes has largely superseded M-mode techniques, although assessment of global systolic function is often performed subjectively.
Structured PICO
I
Intervention
Two-dimensional echocardiographic assessment of left ventricular systolic function
Two-dimensional echocardiography provides essential quantitative and subjective assessments of left ventricular systolic function, though its value as a sequential test is constrained by limited test-retest reliability.
Limitations
- Ejection fraction is strongly influenced by loading conditions and does not correlate well with symptom status
- Value of 2D ejection fraction as a sequential test within individuals is constrained by limited test-retest reliability
- Subjective assessment can be misleading when rhythm is irregular, LV size is very large or small, and at extremes of heart rate
Abstract
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 does 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. Figure 1 Mortality after measurement of ejection fraction by radionuclide ventriculography (one year follow up, Multicentre Post-infarction Research Group, 1983) and after 2D echo measurement of ejection fraction (six month follow up, GISSI study 1993). Note the close correlation of the curves, allowing for the difference in follow up between the two cohorts. ### Subjective assessment Whatever the limitations of subjective assessment, the reality is that echocardiographic assessment of global left ventricular systolic function is usually performed subjectively. Moreover, the eye of an experienced observer is comparable to trackball measurements.1 The situations where this approach can be misleading are when the rhythm is irregular (when examining a long tape run rather than individual cine loops is essential), the LV size is very large or very small, and at the extremes of heart rate. ### Measurement of ventricular volumes and ejection fraction Two dimensional echocardiography approaches for calculation of LV volumes have largely superseded M mode echocardiography techniques that used geometric assumptions based on the minor dimension of the ventricle. A number of 2D approaches have been described (table 1),2–4 some using more sophisticated geometric assumptions. With each of these methods, once volumes have …
Cite This Study
Thomas H. Marwick (Fri,) conducted a review in Cardiac disorders. Two-dimensional echocardiography vs. M-mode echocardiography was evaluated. Two-dimensional echocardiography for calculating left ventricular volumes has largely superseded M-mode techniques, although assessment of global systolic function is often performed subjectively.