Assessment of left ventricular end-systolic elastance from aortic pressure-left ventricular volume relations.
The left ventricular (LV) end-systolic pressure-volume relation (ESPVR) is a load-insensitive method for evaluating LV contractility, which needs invasive measurement. Some noninvasive methods substitute peak aortic pressure (Ps) for end-systolic LV pressure by assuming there is no difference between these pressures. However, this assumption has not been directly validated. With conductance catheter and dual micromanometers, ESPVRs and the slope (EesLv) were constructed from simultaneous LV pressures (LVP) and volumes, aortic pressures (AOP) and LV volumes (Ees(AO)), and Ps and LV end-ejection volumes (VEE) (Ees(PP-EEV)) during preload reduction in 50 subjects. The ratio of steady-state P(s) over V(EE) (P(S)/V(EE)) was also checked. AOP and LVP displayed differences of 11 +/- 6 and -30 +/- 12 mm Hg at the onset and end-ejection, respectively, and -2 +/- 4 mm Hg at end-systole. Ees(AO) and Ees(LV) were nearly identical: Ees(AO) = 0.97 x Ees(LV) + 0.05, r2 = 0.99. Ees(PP-EEV) correlated with EesLV (EesPP-EEV = 0.57 x EesLV + 0.61, r2 = 0.46) but with much more scatter. Ps/V(EE) correlated worst with Ees(LV). Central AOP can be substituted for LVP to derive EesLV. Other estimation methods yield weaker and poor correlations to directly measured Ees.
Lee
Wen-shin
WS
Division of Cardiology, Taipei Veterans General Hospital and the Cardiovascular Research Center, National Yang-Ming University, Taiwan.
Nakayama
Masaru
M
Huang
Wen-Pin
WP
Chiou
Kuan-Rau
KR
Wu
Chih-Cheng
CC
Nevo
Erez
E
Fetics
Barry
B
Kass
David A
DA
Ding
Philip Yu-An
PY
Chen
Chen-Huan
CH
D001011:Aorta / Q000502:physiology*; D006328:Cardiac Catheterization; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D013318:Stroke Volume; D016277:Ventricular Function, Left; D017725:Ventricular Pressure