New Insights into Right Ventricular Function among Patients with Left Ventricular Assist Devices Using High Fidelity Conductance Catheters to Generate Real Time Pressure Volume Loops

Purpose Determine the impact of continuous-flow (CF) left ventricular devices (LVADs) on resting and exertional right ventricular (RV) performance. Methods Eight LVAD patients (all male, 57±8yrs) with normal resting RV function completed invasive hemodynamic assessment during submaximal (mild and moderate, defined by rate of perceived exertion score of 7-9, and 11-13, respectively), and peak exercise on an upright cycle ergometer, and up- and downward pump speed adjustments under supine resting conditions. Results were compared with 7 healthy controls (HC, five males, 37±10yrs). Results Compared to HC, CF-LVAD patients had a lower cardiac output (Qc), oxygen uptake (VO2), and heart rate (HR) at submaximal and peak exercise. Analysis of RV PV loops during exercise testing (Figure 1A-B, and Table 1) shows that RV contractility (Starling contractile Index and DP/DT) was greater, and RV relaxation (-DP/DT), was less than HC during all exercise stages. Among CF-LVAD patients, peak Qc was lower, and DP/DT was similar to, values observed among HC at mild exercise (ie, a similar workload). Changes in pump speed were not associated with any significant change in RV contractility, relaxation, RV end-diastolic pressure, or myocardial energetics (Figure 1C). Conclusion RV function among CF-LVAD patients is characterized by reduced metrics of contractility and relaxation and lower cardiac output compared to healthy individuals exercising at similar workloads. Up- and downward changes in pump speed had minimal impact on resting RV performance.