Brief description

Atrial fibrillation (AF) is a pathological condition characterised by an irregular heart contraction. AF can lead to serious complications such as stroke, ischemic attacks and dementia, due to related thromboembolic events, 90% of which originate in the left atrial appendage (LAA).

This is a sac of muscle tissue protruding from the left atrium (LA).  A number of studies were recently conducted by few research groups, focusing on LA patient specific morphologies. However, the causes and mechanisms responsible for thromboembolism still remain unclear.

In this project, models of LA and LAA integrating the wall motions typical of the cardiac process, neglected in previous CFD studies, were created. These allowed a more comprehensive analysis of the hemodynamic phenomena that occur in normal conditions and after the alterations produced by AF.

This project involves the participation of Dr Alessandra Monteleone and Danila Vella (Ri.MED) and of Mr Giulio Musotto (Ri.MED and University of Palermo).

Impact:

The currently available literature mostly focuses on the analysis of the role of the appendage morphology (this is highly variable from patient to patient) on thrombus formation, relying on rigid-wall models which neglect the changes in wall contractility produced by fibrillation. In this study, instead, computational fluid dynamics approaches are applied to model the contribution of the wall motions of the appendage in both healthy and pathological conditions. The study clearly indicates the contractions of the left atrial appendage as an essential functional factor to maintain healthy fluid dynamic features, identifying its impairment as the primary factor enforcing flow conditions typically associated with clot formation.

Pipeline