Impact of atrial fibrillation on the cardiovascular system through a lumped-parameter approach

TL;DR

This study uses a lumped-parameter model to analyze how atrial fibrillation affects the cardiovascular system, focusing on stochastic heartbeats and reduced contractility, providing new insights into hemodynamic changes during AF.

Contribution

It introduces a novel lumped-parameter approach that incorporates stochastic heartbeat modeling and reduced contractility to better understand AF's systemic effects.

Findings

Reduced cardiac output and ejection fraction during AF

Higher left atrial volumes and pressures in AF cases

Model aligns with clinical observations and reveals new measurable variables

Abstract

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.