Abstract 13214: Right Ventricular-Vascular Coupling in Acute Hemodynamic Stress: A Simple Method of Estimation and Relationship With Right Ventricular Ejection Fraction and Afterload
Objectives: Gold standard of right ventricular (RV) function is ratio of end-systolic to arterial elastance from synchronized volume and pressure measurements. Quantification of ventricular-vascular coupling (VVc) using non-simultaneous common right heart catheterization and cardiac imaging has been described.
Hypothesis: VVc estimated from simultaneous pressure and volume measurements using Swan-Ganz TM (Edwards Lifesciences, Irvine, CA) advanced technology catheters would be feasible and clinically relevant.
Methods: 32 mechanically ventilated adult critically ill trauma/general surgery patients were enrolled within 6 hours of admission. Hemodynamics were transduced every 12 hours for 48 hours. VVc was quantified as ratio of pulmonary artery (PA) effective elastance (Ea) to RV maximal end-systolic elastance (Emax). Mean PA pressure (mPAP) was used as surrogate of RV end-systolic pressure. Right ventricular end-systolic volume index (ESVI) was calculated as difference of end-diastolic volume index and stroke volume index (SVI). E(a) was calculated as (mPAP - PCWP)/SVI and E(max) as mPAP/ESVI.
Results: Serial Ea/Emax inversely correlated with RV ejection fraction (RVEF) (r = -0.89, p <0.001; r = -0.57, p = 0.001; r = -0.73, p <0.001; r = -0.38, p =0.052, and r -0.55, p <0.03) (Figure 1) and pulmonary arterial capacitance (PAC) (r = -0.59, -0.64, -0.49, -0.53, and -0.41, p ≤ 0.03). Pulmonary vascular resistance (PVR) correlated with Ea/Emax(r = 0.66, 0.61, 0.68, 0.66, 0.52, p ≤ 0.004). Non-survivors (n = 7) had higher Ea/Emax (indicating uncoupling) at 48 hours (2.3 ± 1.8 vs. 1.4 ± 1.8, p = 0.036). AUC for Ea/Emax at 48 hours and mortality was comparable to RVEF.
Conclusions: In mechanically ventilated critically ill and/or injured adults, estimation of VVc using advanced technology pulmonary artery catheter is feasible. Ea/Emaxis related to PVR and inversely related to RVEF and PAC. Estimation of Ea/Emaxmay assist in optimization of resuscitation.
- ventricular-vascular coupling
- right ventricular function
- right ventricular afterload
- critical care
Author Disclosures: M. Mehmood: None. R.W. Biederman: Research Grant; Modest; NHLBI. M.C. McCarthy: None. K.M. Tchorz: Research Grant; Modest; American Association for the Surgery of Trauma. Other Research Support; Modest; NIH Loan Repayment Program Award.
- © 2015 by American Heart Association, Inc.