Doppler characteristics of late-diastolic flow in the left ventricular outflow tract.

This study characterizes the relationship between late-diastolic Doppler detected forward flow in the left ventricular outflow tract and diastolic transmitral flow. Pulsed-wave Doppler interrogation of the left ventricular outflow tract, in a prospective consecutive series (n = 137), revealed the presence of end-diastolic forward flow in 83% of the patients studied. Further quantification of both flow signals was performed in 67 patients. Pulsed-wave mapping demonstrated that peak velocity of the end-diastolic left ventricular outflow tract signal (J wave) was maximal, 2.6 +/- 0.7 cm from the aortic valve anulus, and occurred 48 +/- 34 milliseconds after the peak transmitral atrial velocity flow signal. Peak J velocity ranged from 25 to 118 cm per second and correlated with peak A velocity (r = 0.69, p less than 0.001). Peak J velocity was inversely related to left ventricular end-diastolic dimension (r = -0.53, p less than 0.0001) and left ventricular end-diastolic volume (r = -0.43, p less than 0.004). There was no relationship between J wave velocity and early diastolic filling. We concluded that a late-diastolic forward flow signal is commonly observed in the left ventricular outflow tract. It is a manifestation of transmitral atrial systolic flow in the left ventricular outflow tract and is determined predominantly by peak transmitral atrial velocity and left ventricular size.