Table 4. Correlation coefficients (r) between the slope of the relationship between cardiac output and oxygen uptake (CO slope) and hemodynamic and exercise variables. CHF Subjects CO Slope p value Peak VO2 .51 <.001 Peak CO .48 .001 Peak CI .54 <.001 Peak VET .22 .18 VE/VCO2 Slope -.08 .61 OUES -.07 .66 NYHA Class .05 .75 EF -.02 .89 Normal Subjects CO Slope p value Peak VO2 .17 .59 Peak CO .79 <.002 Peak CI .81 .001 Peak VET -.50 .10 VE/VCO2 Slope -.36 .25 OUES .58 .05 EF .28 .40 VO = oxygen uptake; CO = cardiac output; CI = cardiac index; VET = ventricular ejection time; OUES = oxygen uptake efficiency slope; NYHA = New York Heart Association; EF = ejection fraction.