Chest, Vol 96, 275-280, Copyright © 1989 by American College of Chest Physicians

ARTICLES

Left ventricular function during stable sustained ventricular tachycardia. Hemodynamic and echo-Doppler analysis

SB Baron, SK Huang and KA Comess
Section of Cardiology, University of Arizona Medical Center, Tucson.

To assess the left ventricular function during sustained stable ventricular tachycardia (VT), ten patients, aged 58 to 74, underwent simultaneous echo-Doppler and hemodynamic studies during sinus rhythm and induced sustained stable monomorphic VT. The VT cycle length was 447 +/- 92 ms (mean +/- SD). During VT, cardiac index fell from 2.32 +/- 0.54 to 1.62 +/- 0.63 L/min/m2 (p less than 0.001), and systemic systolic blood pressure fell from 129 +/- 18 to 107 +/- 18 mm Hg (p less than 0.001), while left ventricular end-diastolic pressure showed a rising trend from 9 +/- 7 to 15 +/- 12 mm Hg, and pulmonary artery wedge pressure rose from 10.2 +/- 1.6 to 24.2 +/- 2.3 mm Hg (p less than 0.005). By echo-Doppler the ejection fraction and the presence and degree of valvular regurgitation were not significantly changed during VT. The mean maximal left ventricular inflow tract velocities, mean time velocity integrals, and the mean time velocity integrals normalized for heart rate (measures of left ventricular diastolic filling) decreased from 0.59 +/- 0.074 to 0.40 +/- 0.053 m/s (p less than 0.05), from 0.12 +/- 0.029 to 0.021 +/- 0.012 m (p less than 0.001), and from 7.43 +/- 1.20 to 3.21 +/- 1.49 m x beats/min (p less than 0.001) during VT, respectively. We conclude that hemodynamic changes during stable sustained VT are neither associated with significant changes in systolic left ventricular function nor related to valvular regurgitation and are likely caused by impaired left ventricular diastolic filling.