  Atrial fibrillation (AF) is the most common arrhythmia affecting millions of
people in the Western countries and, due to the widespread impact on the
population and its medical relevance, is largely investigated in both clinical
and bioengineering sciences. However, some important feedback mechanisms are
still not clearly established. The present study aims at understanding the
global response of the cardiovascular system during paroxysmal AF through a
lumped-parameter approach, which is here performed paying particular attention
to the stochastic modeling of the irregular heartbeats and the reduced
contractility of the heart. AF can be here analyzed by means of a wide number
of hemodynamic parameters and avoiding the presence of other pathologies, which
usually accompany AF. Reduced cardiac output with correlated drop of ejection
fraction and decreased amount of energy converted to work by the heart during
blood pumping, as well as higher left atrial volumes and pressures are some of
the most representative results aligned with the existing clinical literature
and here emerging during acute AF. The present modeling, providing new insights
on cardiovascular variables which are difficult to measure and rarely reported
in literature, turns out to be an efficient and powerful tool for a deeper
comprehension and prediction of the arrythmia impact on the whole
cardiovascular system.
