MECHANODYNAMICS AT THE INTERVENTRICULAR SULCUS : Reciprocal Effect of the Ventricles on the Ventricular Function

Abstract

The forces acting on IVS were analyzed to delineate reciprocal effects of the two ventricles on the ventricular function as a whole. The resultant force (F_T) was dependent on the LV pressure but independent on the RV pressure. But the composite forces (F₁ and F₂) of F_T were affected by the LV and RV pressures. In a normal heart F₁ increased with increasing LV and/or RV pressures. But in F₂ increase occurred only with increasing RV pressure. In the LV pressure increase occurred only when the RV pressure was 10 mmHg and decrease did when the RV pressure was 50 mmHg, while stable at 30 mmHg. Directions of both the forces (F₁ and F₂) diverged as the RV pressure increased and the LV pressure decreased. When FRV was hypertrophic, increases of the magnitudes of the forces were decreased when the pressures of the LV and RV were higher. The angle between the forces was also decreased so that the efficiency of the forces was risen. When a portion of the ventricles lost its contractility, F_T increased, particularly, when FLV lost its contractility. But these increases seemed to well be within range of compensation.