A COMPREHENSIVE MODEL FOR RIGHT-LEFT HEART INTERACTION UNDER THE INFLUENCE OF PERICARDIUM AND BAROREFLEX

A phenomenological model of the cardiopulmonary circulation is develop ed with a focus on the interaction between the right heart and the lef t heart. The model predicts the hemodynamic consequences of changing c irculatory parameters in terms of a broad spectrum of pressure and flo w waveforms. Hemodynamics are characterized by use of an electrical an alog incorporating mechanisms for transseptal pressure coupling, peric ardial volume coupling, intrathoracic pressure, and baroreflex control of heart rate. Computer simulations are accomplished by numerically i ntegrating 28 differential equations that contain nonlinear and time-v arying coefficients. Validity of the model is supported by its accurat e fit to clinical pressure and Doppler echocardiographic recordings. T he model characterizes the hemodynamic waveforms for mitral stenosis, mitral regurgitation, left heart failure, right heart failure, cardiac tamponade, pulsus paradoxus, and the Valsalva maneuver. The wave shap es of pulmonary capillary wedge pressure under the above conditions ar e also accurately represented. Sensitivity analysis reveals that simul ated hemodynamics are insensitive to most individual model parameters with the exception of afterload resistance, preload capacitances, intr athoracic pressure, contractility, and pericardial fluid volume. Basel ine hemodynamics are minimally affected by transseptal coupling (up to 2%) and significantly affected by pericardial coupling (up to 20%). T he model should be useful for quantitative studies of cardiopulmonary dynamics related to the right-left heart interaction under normal and disease conditions.