Mechanical principle of the respiration-driven variation of cardiac function:echocardiographic study of factors affecting the swing of interventricular septum / 中华超声影像学杂志

Objective To investigate the affecting factors of interventricular septum (IVS) swing by study of the mechanical model of the respiration-driven variation of cardiac function using echocardiography.Methods In present study,the equivalent mechanical model of septal swing in previous study was used.By changing the end-diastolic pressure difference between the simulated right and left ventricles and simulated intrapericardial pressure,the subsequent influences on IVS swing using echocardiography were observed.Results Under the rhythmic respiratory intrathoracic pressure change(RIPC)(0--4 mm Hg,1 mm Hg =0.133 kPa),the swing amplitude of simulated IVS increased with decrease of the simulated end-diastolic pressure difference between the simulated right and left ventricles (2.2-17.6 mm).With increasing of the simulated intrapericardial pressure,the simulated right ventricle and left ventricle collapsed in succession,the swing amplitude of simulated IVS also increased to a maximal amplitude of 22.4 mm.Conclusions The affecting factors of IVS swing including the magnitude of RIPC,the end-diastolic pressure difference between the two ventricles and the intrapericardial pressure.