Background: Tissue Doppler echocardiography reveals characteristic patterns of myocardial velocities within systole and diastole which are not well understood.
Aim: The purpose of this study was to determine the relationship of myocardial velocity patterns, as assessed by tissue Doppler echocardiography, to the contraction and relaxation phases of the cardiac cycle, as determined during cardiac catheterization.
Methods: Recordings of left ventricular/aortic and left ventricular/pulmonary wedge pressures were obtained simultaneously with apical tissue Doppler echocardiographic images of the left ventricle. A total of 210 cardiac cycles from 22 patients (mean age 58 years, 18 male) undergoing cardiac catheterization were analysed. The time intervals of the different phases of the cardiac cycle were measured from the pressure tracings. These time intervals were correlated to the interfaces of colour myocardial velocity patterns obtained by M-mode tissue Doppler echocardiography.
Results: There was a good correlation between the time intervals assessed haemodynamically and those based on the different velocity interfaces obtained with M-mode tissue Doppler echocardiography. Comparable time intervals (from the R wave) obtained by pressure recordings and tissue Doppler echocardiography were, respectively: isovolumic contraction (70 +/- 14 vs 67 +/- 9 ms, r = 0.79); rapid ejection (206 +/- 54 vs 202 +/- 49 ms; r = 0.95); late ejection (357 +/- 36 vs 346 +/- 42 ms. r = 0.93); isovolumic relaxation (405 +/- 43 vs 409 +/- 56 ms; r = 0.95); rapid filling (514 +/- 67 vs 523 +/- 64 ms, r = 0.91); diastasis (697 +/- 153 vs 709 +/- 146 ms, r = 0.98); atrial contraction (890 +/- 128 vs 899 +/- 132 ms, r = 0.96).
Conclusion: Tissue Doppler echocardiography has the potential to accurately measure the different phases of the cardiac cycle which until now could only be determined invasively. It may provide a sensitive method for the assessment of changes in both cardiac contraction and relaxation in different clinical settings.