Relationship Between Regional and Global Left Ventricular Systolic and Diastolic Function in Patients With Coronary Artery Disease Assessed by Strain Rate Imaging

BACKGROUND: The relationship between regional and global left ventricular function has not been evaluated. The present study aimed to assess whether regional myocardial contraction and relaxation reflect global left ventricular systolic and early diastolic function, respectively. METHODS AND RESULTS: The study involved 45 patients with coronary artery disease (CAD). Conventional echocardiography was performed, and segmental peak strain rate (SR) in the systole (S(SR)) and early diastole (E(SR)) were obtained from tissue Doppler imaging in each of 18 segments of the left ventricular myocardium from the apical views. The E(SR) was significantly correlated with S(SR) in all studied segments (r=0.55, p<0.0001). The average values of SR indices in each patient were defined as S(SR) index and E(SR) index, which were derived by dividing the summed value of the S(SR) or E(SR) by the number of respective assessable segments. A significant positive relationship was observed between the S(SR) index and left ventricular ejection fraction (r=0.85, p<0.0001). Also, there was a positive correlation between the E(SR) index and mitral flow E (r=0.68, p<0.0001). CONCLUSIONS: Regional myocardial contraction and relaxation, as assessed by SR imaging, were closely related in patients with CAD. Furthermore, regional myocardial contraction and relaxation are important factors affecting global left ventricular systolic and early diastolic function.