Speckle tracking echocardiography-determined measures of global and regional left ventricular function correlate with functional capacity in patients with and without preserved ejection fraction

Background: Standard measures of left ventricular systolic and diastolic function often fail to identify left ventricular dysfunction in patients with heart failure and do not correlate with measures of functional capacity. Aim: To determine if speckle tracking echocardiography (STE)-determined measures of global and regional myocardial contractility have a linear association with functional capacity in patients with and without preserved ejection fraction. Methods: In 68 adult patients, functional status was estimated with the Duke Activity Status Index (DASI), left ventricular ejection fraction was determined with Simpson's biplane method, and QLAB advanced quantification software (Philips, The Netherlands) was used to determine peak measures of strain. Results: Global and regional measures of longitudinal, circumferential, and radial strain had a strong linear association with the DASI score. Longitudinal strain in the inferolateral segments had the strongest correlation with DASI (r = -0.72, P < 0.001). In patients with an ejection fraction >= 45%, ejection fraction and E/e' had no correlation with DASI, whereas longitudinal strain in the inferolateral segments had significant correlation with DASI (r = -0.53, P = 0.03, n = 16). Conclusions: STE-determined measures of global and regional left ventricular function have a strong linear association with estimates of functional capacity in patients with and without preserved ejection fraction. STE-determined measures of strain, especially longitudinal strain, are likely to be important targets for therapy and should be considered in future studies aimed at improving our diagnosis of left ventricular inadequacy in patients with heart failure, especially those with preserved ejection fraction.