739-5 Assessment of the Immediate Effects of Mechanical Left Ventricular Assistance on Right Ventricular Performance by Automated Pressure-Area Relations

Abstract

Right ventricular (RV) performance is important for global cardiac function in pts with severe heart failure. The use of a mechanical LV assistance device (LVAD) may be life-saving in these pts. However, the physiological effects of LVAD on RV performance have been difficult to evaluate. To determine the feasibility of a new method to assess RV performance with LVAD, 6 pts aged 44 ± 14 yrs, were studied before and immediately after Novacor LVAD implantation. Simultaneous measures of RV cross-sectional area by transesophageal echo automated border detection and high fidelity pressure were used to construct pressure-area loops on-line. Data were acquired during steady state apnea and with IVC occlusions (example shown). The following RV indices were obtained: maximum & minimum areas, 2D ejection fraction (2DEF), systolic pressure, stroke force (SF) ∫ pressure d area, end-systolic elastance (Ees), and preload recruitable SF (PRSF). An immediate decrease in RV systolic pressure (35 ± 7 to 28 ± 6 mmHg, p < 0.05) and an immediate increase in RV ejection (RV 2DEF: 21 ± 8 to 33 ± 12%, p < 0.05) occurred with LVAD. No significant changes occurred in RV SF; 123 ± 64 to 124 ± 65 mmHg-cm 2 , Ees; 5.7 ± 3.8 to 3.5 ± 1.4 mmHg/cm 2 , or PRSF; 18 ± 14 to 19 ± 15 mmHg. These data support the unloading effect of LVAD on improving RV ejection, rather than improved RV contractility. Automated pressure-area relations may have potential to assess the effects of LVAD on RV performance.