Atrial fibrosis quantified using late gadolinium enhancement MRI is associated with sinus node dysfunction requiring...

Area of Science:

• Cardiology
• Medical Imaging

Background:

• Sinus node dysfunction (SND) often presents with atrial arrhythmias, sinus pauses, and bradycardia.
• Atrial fibrosis is the suspected underlying cause of SND.
• Late gadolinium-enhanced MRI (LGE-MRI) quantifies atrial fibrosis.

Purpose of the Study:

• To assess the predictive value of atrial fibrosis, quantified by LGE-MRI, for significant SND requiring pacemaker implantation.
• To investigate the association between atrial fibrosis and the need for pacemaker implantation in patients with atrial fibrillation (AF).

Main Methods:

• Three hundred forty-four AF patients undergoing catheter ablation had LGE-MRI to quantify left atrial (LA) and right atrial (RA) fibrosis.
• Patients were followed prospectively for ~329 days with regular ambulatory monitoring.
• Pacemaker implantation was performed for symptomatic pauses and bradycardia per guidelines.

Main Results:

• Average LA fibrosis was 16.7% and RA fibrosis was 5.3%.
• LA fibrosis stage was a significant predictor of pacemaker implantation (OR, 2.2; AUC, 0.704).
• Twenty-two patients (6.4%) required pacemaker implantation, with a mean atrial fibrosis of 23.9% in this group.

Conclusions:

• LGE-MRI quantification of atrial fibrosis shows preferential LA involvement in AF patients.
• Significant atrial fibrosis, particularly in the LA, is associated with SND requiring pacemaker implantation.