A comparison of tissue Doppler imaging and velocities of transmitral flow in children with elevated left ventricular preload

Compared with transmitral velocities of flow, myocardial wall velocities ob tained by tissue Doppler imaging are less influenced by left atrial pressur e. The data supporting this assumption, however, are limited in patients wi th congenital cardiac disease. The aim of this study was to compare the eff ects of left ventricular preload on transmitral inflow and velocities asses sed by tissue Doppler imaging. Tissue Doppler imaging, and conventional Dop pler echocardiography with simultaneous invasive hemodynamic studies, were performed in 33 patients with a simple ventricular septal defect or patency of the arterial duct. Transmitral velocities (E, A) and mitral annular vel ocities (Ea, Aa) were measured, permitting calculation of the ratio off to Ea. The ratio of pulmonary to systemic flows, and mean left atrial pressure , were also measured. In 10 of 33 patients, echocardiographic and hemodynam ic studies were performed 4 to 5 months after surgery. The E and A values in the patients were greater than those in the controls (p < 0.01). In contrast, neither Ea nor Aa differed between the two group. The ratio of E to Ea in the patients increased significantly compared with that in the controls (8.9 +/- 2.1 vs 7.3 +/- 1.3, p < 0.01). The E value wa s directly related to mean left atrial pressure and the ratio of pulmonary to systemic flows. The velocities measured by Tissue Doppler imaging, howev er, had no significant relationship to either of these measurements. The ra tio of E to Ea correlated well with mean left atrial pressure (r = 0.75, p < 0.01). In 10 post-operative patients, the values for E and A decreased fr om 119 +/- 14 to 89 +/- 10 cm/sec (p < 0.01) and from 91 +/- 22 to 61 +/- 9 cm/sec (p < 0.01), respectively. No significant changes were noted in the values of Ea and Aa. The ratio off to Ea, and mean left atrial pressure, de creased from 10.3 +/- 1.9 to 8.2 +/- 1.5 (p < 0.01) and from 11.0 +/- 1.8 t o 7.4 +/- 1.0 mmHg (p < 0.01), respectively. The percentage change in left atrial pressure correlated with the percent change in the ratio off to Ea ( r = 0.64, p < 0.05). The present study showed that the velocities obtained with tissue Doppler i maging are less dependent on mean left atrial pressure in children with ele vated left ventricular preload caused by a left-to-right shunt.