Four-Quadrant Visualization of Systemic Circulatory Equilibrium - Right Ventricular Failure after Left Ventricular Assist Device Implantation.

Right ventricular failure (RVF) is a serious adverse event after left ventricular assist device (LVAD) implantation, but difficult to be characterized. This study aimed to visualize the dynamic circulatory equilibrium of acute RVF after LVAD implantation using a new four-quadrant diagrams constructed by (1) cardiac function with central venous pressure (CVP) and cardiac index (CI) axes, (2) arterial vascular resistance with CI and mean blood pressure (mBP) axes, (3) pressure-diuretic function with mBP and net urinary sodium output (net U-Na) axes, and (4) venous compliance with net U-Na and CVP axes. Twenty LVAD patients were stratified into two groups, S (≤10 days) and L (>10 days), according to duration of postoperative inotropic support. The preoperative equilibrium loops were small in both groups. In the early postoperative phase, the loop in group S became dramatically enlarged to the left and upwards, indicating increased CVP and CI by LVAD support. In group L, however, augmentation of CI was smaller despite similarly increased CVP and net U-Na was decreased despite increased mBP. In the late postoperative phase, the equilibrium loop in group L recovered as similar to that seen in group S. Thus, acute RVF, as shown in group L, was characterized by the shape of the loop constructed by marked increased CVP, relatively small increase in CI and concomitant impairment of pressure natriuresis. In conclusion, the novel four-quadrant presentation of systemic circulatory equilibrium provides clear visualization of RVF after LVAD implantation, thus serving as a useful guide for prompt and optimal management.