Continuous Monitoring of Right Ventricular Function with a 3-Axis Accelerometer during Left Ventricular Assist Device Implantation

Abstract

Purpose Right ventricular (RV) failure during treatment of end stage heart failure with left ventricular assist device (LVAD) is a severe complication. No method for continuous monitoring on RV function exists. We successfully used an epicardial 3-axis accelerometer for real time monitoring of RV contractility during LVAD implantation. Methods and Materials A 61 years old male patient with end stage heart failure (LV EF 20%, MPAP 31 mmHg), IABP and inotropic support received LVAD treatment (bridge to transplantation). LVAD implantation was performed with extra corporal circulation (ECC). A 3-axes accelerometer (2x2x5 mm) was sutured on the RV anterior wall after chest opening. RV accelerations in longitudinal, cirumferential and radial directions were simultaneously sampled and the calculated velocities signals were displayed in real time on a monitor together with ECG. Results RV function was possible to monitor in real time with the accelerometer and velocities looked similar to tissue velocities obtained by echocardiography. Systolic contraction and diastolic filling were easily identified Figure 1 . A severely depressed RV function was detected with the accelerometer after aortic cross clamp removal (reperfusion), with loss of longitudinal and circumferential contractions. It was possible to precisely monitor recovery of RV function during reperfusion, weaning from ECC and initiation of LVAD, and to identify differences in RV contraction directions during loading and unloading. Conclusions RV function can be precisely monitored in real time by use of a 3-axes accelerometer. The method has a great potential in detecting clinical adverse outcomes during LVAD treatment.