Table 3

Hemodynamic Variables for All Animals Before (Controls) and After Induction of LBBB

Controls (n = 8)LBBB (n = 8)ANOVA
BaselineAortic ConstrictionBaselineAortic Constriction
Heart rate, beats/min124 ± 16122 ± 17127 ± 15126 ± 15NS
QRS duration, ms54 ± 555 ± 5112 ± 10113 ± 6NS
LV pressure maximum, mm Hg100 ± 12125 ± 1894 ± 10118 ± 16NS
LV end-diastolic pressure, mm Hg10 ± 311 ± 411 ± 313 ± 4NS
Minimum LV pressure, mm Hg6 ± 38 ± 38 ± 311 ± 4p < 0.05
Tau, ms36 ± 541 ± 745 ± 851 ± 10NS
LV dP/dtmax, mm Hg/s1,303 ± 2301,318 ± 1951,037 ± 1601,127 ± 197NS
LV stroke volume, ml17 ± 414 ± 216 ± 411 ± 4NS
LV stroke work, mm Hg·ml1,259 ± 4121,126 ± 4421,052 ± 411846 ± 575NS
Septal systolic shortening, mm2.4 ± 0.71.8 ± 0.61.2 ± 0.50.0 ± 0.8p < 0.05
LV lateral wall systolic shortening, mm4.8 ± 2.04.1 ± 1.84.9 ± 1.74.4 ± 1.3NS
Septal work, mm Hg·mm496 ± 161440 ± 22478 ± 171−161 ± 160p < 0.05
LV lateral wall work, mm Hg·mm576 ± 200478 ± 183655 ± 167610 ± 301NS

Values are mean ± SD.

dP/dtmax = maximum rate of rise of left ventricular pressure; tau = time constant of left ventricular relaxation; other abbreviations as in Tables 1 and 2.

  • p < 0.05 vs. normal afterload.

  • p < 0.05 vs. controls. Dimension data are circumferential. ANOVA refers to the interaction effect from a 2-way repeated-measures ANOVA.