Influence of afterload on left ventricular radial and longitudinal systolic functions: A two-dimensional strain imaging study

Abstract

Aims This study aimed to assess the influence of afterload alteration on radial (R) and longitudinal (L) left ventricular (LV) systolic regional functions.Methods and resultsWe analysed systolic myocardial function by two-dimensional strain (2D-S) and sonomicrometry (SS) in an experimental pig model of aortic banding. Both radial and longitudinal functions were analysed in six open-chest pigs under various loading conditions: baseline and graded aortic banding (subsequent increase in LV pressure of 10, 20, and 40 mmHg). Both systolic 2D-Slong and 2D-Srad were significantly correlated with SSlong and SSrad (r = 0.63, P < 0.001 and r = 0.65, P < 0.01, respectively). At a low increase in LV afterload, 2D-Srad was still preserved whereas 2D-Slong significantly decreased. When LV afterload was subsequently increased, both 2D-Srad and 2D-Slong significantly decreased. Difference in dependence to wall stress might explain these different behaviours.Conclusion2D-S shows a different response in longitudinal and radial functions to increased afterload. Longitudinal function is early impaired, whereas radial function remains preserved. This finding justifies the combined assessment of both radial and longitudinal regional myocardial functions to characterize myocardial dysfunction and might help to better identify the transition to heart failure in pressure-overload cardiomyopathy.