ABSTRACT
Doppler examination of mitral inflow has been widely used to evaluate left ventricular [LV] diastolic function. Recently tissue Doppler imaging [TDI] of mitral annulus is used to provide additional insights in the assessment of diastolic dysfunction. This study was aimed to assess the value of TDI indices in evaluation of LV diastolic dysfunction and determination of its pattern. Transmitral Doppler flow [TMF] parameters were obtained in 32 patients [5 F and 27 M], with cardiac diseases known to affect diastolic function, including 26 patients having IHD and 6 hypertensive patients. Standard TMF parameters included early [E] and late [A] velocities, E/A ratio, E deceleration time [EDT], isovolumic relaxation time [IVRT], peak filling rate normalized to MV stroke volume [PFRn]. Pulmonary venous flow [PVF] parameters were also taken including systolic and diastolic velocities [Sv and Dv], systolic and diastolic integrals [Si and Di], Sv/Dv ratio, Si/Di ratio, atrial reversal velocity [ARv] and integral [ARi]. Patients were subdivided into 3 groups. Group 1 included 20 patients with abnormal relaxation, having PFRn <4.5 sv/sec. Group 2 included 5 patients with pseudonormal pattern, having normal TMF with abnormal PVF parameters, and Group 3 [7 patients] with restrictive filling pattern [RFP], having PFRn >6 sv/sec and abnormal PVF parameters. TDI parameters taken included early [Em], late [Am] diastolic myocardial velocities and their ratio [Em/Am], all measured by both spectral pulsed Doppler and trace profile. There was no significant difference in Em values between the 3 study groups [7.8 +/- 2.9, 7.8 +/- 1.3 and 8.7 +/- 2.6 cm/sec respectively]. In contrast, Am was significantly lower in Group 3 [4.7 +/- 1.8 cm/sec] than in Groups 1 and 2 [11.1 +/- 3.3 and 12.2 +/- 2.0 cm/sec respectively], p <0.001. Em/Am ratio was significantly higher in Group 3 [2.04 +/- 0.97] than in Group 1 [0.73 +/- 0.28] and Group 2 [0.65 +/- 0.11], p <0.001. Em/Am ratio showed significant correlation to: E/A ratio [r = 0.77, p <0.001], PFRn [r = 0.61 p <0.001], IVRT [r = -0.41, p <0.05], EDT [r = -0.48, p <0.01] and S/D ratio of PVF [r = -0.62, p <0 001]. No significant correlation was found between Em and E velocities. In contrast, a highly significant correlation was found between Am and A velocities [r = 0.68, p <0.001]. Only 2 patterns of diastolic dysfunction can be discriminated using TDI parameters: [abnormal relaxation] with decreased both Em velocity and Em/Am ratio and increased Am velocity. The other pattern [restrictive filling pattern] shows decreased Em velocity, increased Em/Am ratio and markedly diminished Am velocity. Mitral annular TDI can reliably diagnose and discriminate patterns of LV diastolic dysfunction. Further studies are needed to identify whether TDI is only complementary or it can substitute standard TMF parameters