Cardiovascular disintegration: A conceptual, model-based approach to heart failure hemodynamics

Abstract

Objective: The current understanding of heart failure (HF) largely centers round left ventricular (LV) function; however, disorders in serial integration of cardiovascular system may cause a hemodynamic picture similar to left-sided HF. Therefore, focusing only on LV function may be a limited and misleading approach. We hypothesized that cardiovascular system has four major integration points, and disintegration in any of these points may produce the hemodynamic picture of HF.

Methods: We used a computational model in which mechanical properties of each chamber were characterized using time-varying elastance, and vascular beds were modeled by series of capacitances and resistances. The required percent changes in stressed volume (Vstressed) was presented as a measure of congestion susceptibility.

Results: As mean systemic pressure is closely correlated with pulmonary capillary wedge pressure (PCWP), arteriovenous disintegration can create a diastolic dysfunction pattern, even without any change in diastolic function. For 10%, 20%, 30%, 40%, and 50% interventricular disintegration, required Vstressed for reaching a PCWP over 20 mmHg was decreased by 42.0%, 31.2%, 22.5%, 15%, and 8.3%, respectively. Systolodiastolic disintegration, namely combined changes in the end-diastolic and systolic pressure-volume curves and ventriculoarterial disintegration significantly decreases the required percent change in Vstressed for generating congestion.

Conclusion: Four disintegration points can produce the hemodynamic picture of HF, which indicates that combination of even seemingly mild abnormalities is more important than an isolated abnormality in a single function of a single chamber. Our findings suggest that a "cardiovascular disintegration" perspective may provide a different approach for assessing the HF syndrome.