Left Ventricular Function
Assessment of LV systolic function is a central part of the evaluation of cardiac disease. LV function is important for guiding patient management and prognosis, and it is essential in the evaluation of patients with known or suspected cardiac disease. There is a close relationship between declining LV function and poor prognosis. This relationship is related to the degree of LV systolic dysfunction. LV systolic dysfunction following a myocardial infarction is associated with a 2.4- fold increase in the relative risk of death. Greater degrees of LV systolic dysfunction is associated with a worse prognosis. Survival of patients with an EF of less than 35% is 21% at 12-years and 54% for those with an LVEF of 35% to 49%. Both survival rates were markedly worse than that of patients with normal LV systolic function. Numerous methods can be used in LV assessment from very simple linear techniques (which are no longer recommended by current guidelines) to the more complex 3D models which are out of the scope of the Focused Cardiac (FoCUS) component of POCUS.
The essence of FoCUS is mainly a dichotomous interpretation of the findings to answer questions that are crucial to the clinical decision-making process. The diagnostic approach of FoCUS is qualitative or semiquantitative and the examination is conducted without the requirement of performing specific measurements. We will explore some qualitative appreciation of sizes and function of the LV and go slightly beyond this scope and explore some popular easy to use quantitative assessments and remind you of their limitations. This is so that you have several tools to use depending on your ultrasound's capability.
1. Visual Global Assessment
The objectives of FoCUS is to be qualitatively evaluate a LV that is dilated or non dilated, hypertrophic, hypokinetic and a function that is hyperdynamic, depressed or severely depressed. As it turns out, visual estimations of global function approximate formal quantitative methods in trained observers and we will use this to out advantage by comparing the different ranges and we will use the parasternal short axis view and apical 4 chamber view for comparison purposes.
Severely Depressed LV
Global systolic function is severely depressed with an EF<30%. The RV function is also depressed on the apical 4 chamber view.