Abstract 1862: A New Automated Drug Delivery System to Restore Hemodynamics of Decompensated Heart Failure in Closed-Chest Clinical Settings: Potential Application for Clinical Research
Background: Automated drug delivery system to optimize hemodynamics is worth developing, since management of decompensated heart failure is often difficult. The system is useful to separate cardiac protective effects of clinical therapies (e.g., hANP) from hemodynamic effects. We have succeeded in our prototype to control left ventricle pumping ability (SL) by dobutamine, stressed blood volume (V) by dextran and arterial resistance (R) by nitroprusside in open-chest dogs, so as to restore normal arterial pressure (AP), left atrial pressure (PLA) and cardiac output (CO). However, requirement of continuous measurement of SL and PLA make it difficult to apply for clinical settings.
Methods: To overcome the limitation, we controlled right ventricle pumping ability (SR), by assuming nearly parallel changes in left and right pumping functions. We estimated PLA by linear regression of it over pulmonary arterial pressure (PPA), that was calibrated every 30 min.
Results: In anesthetized dogs (n=10) with acute decompensated heart failure, the new system accurately estimated PLA from PPA (RMS=1.3±0.3 (SD) mmHg), restored all mechanical properties (SR, V, R) within 20 min, and normalized AP (85.6±18.6 to 94.4±13.1 mmHg), CO (69.6±9.8 to 102.3±8.0 ml·min-1·kg-1) and PLA (19.3±2.8 to 13.5±1.2 mmHg). The restored hemodynamics was maintained for 90 min with small steady-state deviations from respective targets [AP, 4.4±3.7 mmHg; CO, 3.0±2.6 ml·min-1·kg-1; PLA, 0.6±0.5 mmHg].
Conclusion: The new system with SR control and PLA estimation successfully restored normal hemodynamics in decompensated heart failure in clinical settings.