Left-Ventricular Function Quantitative Parameters and Their Relationship to Acute Loading Variation: From Physiology to Clinical Practice

Because of its relevance for patient prognosis, ventricular function is quantified daily by clinicians. This analysis turns out to be complex as a multitude of parameters are available, that all come with their measurement limitations and pitfalls in interpretation, because they are influenced by loading conditions and heart rate. Proper markers of myocardial contractility should indeed be able to detect subtle dysfunction, independent of loading and heart rate. Moreover, in the current multi-modal imaging environment these parameters can be assessed by different modalities, each with their own strengths and weaknesses and variable “normal” values. This report wants to provide an overview of the quantification of ventricular function in perspective to a physiological background of myocardial contractility. We discuss the most routinely used contractility parameters together with their sensitivity to loading modification. We stress the importance of understanding the relationship between loading and contractility, in order not to be misled by numbers, but to globally evaluate these numbers integrated in a hemodynamic context.