Cardiac Time Intervals by Tissue Doppler Imaging M-Mode: Normal Values and Association with Established Echocardiographic and Invasive Measures of Systolic and Diastolic Function

Purpose To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPI TDI ) and the conventional method of obtaining MPI (MPI Conv ), with established echocardiographic and invasive measures of systolic and diastolic function. Methods In a large community based population study (n = 974), where all are free of any cardiovascular disease and cardiovascular risk factors, cardiac time intervals, including isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET) were obtained by TDI M-mode through the MV. IVCT/ET, IVRT/ET and the MPI ((IVRT+IVCT)/ET) were calculated. We also included a validation population (n = 44) of patients who underwent left heart catheterization and had the MPI TDI and MPI Conv measured. Results IVRT, IVRT/ET and MPI all increased significantly with increasing age in both genders (p<0.001 for all). IVCT, ET, IVRT/ET, and MPI differed significantly between males and females, displaying that women, in general exhibit better cardiac function. MPI TDI was significantly associated with invasive (dP/dt max) and echocardiographic measures of systolic (LVEF, global longitudinal strain and global strainrate s) and diastolic function (e’, global strainrate e)(p<0.05 for all), whereas MPI Conv was significantly associated with LVEF, e’ and global strainrate e (p<0.05 for all). Conclusion Normal values of cardiac time intervals differed between genders and deteriorated with increasing age. The MPI TDI (but not MPI Conv ) is associated with most invasive and established echocardiographic measures of systolic and diastolic function.