Persistent lone atrial fibrillation: Clinicopathologic study of 19 cases

Shortened telomere length is associated with paroxysmal atrial fibrillation among cardiovascular patients enrolled in the Intermountain Heart Collaborative Study

“…The explanation for and mechanism underlying this observation among AF types is unclear, however a recent study that specifically addressed oxidative injury and atrial fibrosis provides some insight into our findings. 6 In that study, tissue changes such as atrial fibrosis and myolytic damage from oxidative damage occurred essentially at the transition from paroxysmal to persistent AF. That histologic study showed the importance of oxidative stress injury in AF etiology, but also found that after injury had occurred, AF subtype and progression was variable and independent of the initial triggers and the spectrum of tissue lesions arising from oxidative stress.…”

“…Atrial fibrosis has been attributed in part to structural and molecular changes from oxidative stress. 6 Furthermore, oxidative damage to mitochondrial DNA and mitochondrial DNA mutations have been associated with AF genesis. 7,8 Consistent with these findings, mitochondrial dysfunction has also been identified as a risk factor for post-cardiac surgery AF, a transient, generally self-limited form of AF.…”

Atrial Fibrillation Pathophysiology and Prognosis

“…Clinicopathologic studies have demonstrated that patients with persistent AF have significantly higher percentage of interstitial fibrosis of both the left and right atria, as well as the PVs, compared with controls. 41,42 The extent of fibrotic changes may actually be greater in patients with a history of permanent rather than paroxysmal AF. 43 Although areas of atrial scarring had been previously characterized invasively with electroanatomic voltage mapping in patients undergoing AF ablation, 44 more recently the role of the noninvasive evaluation with delayed-enhancement CMR (DE-CMR) imaging has been characterized ( Figure 3).…”

Left Atrial Appendage Exclusion for Atrial Fibrillation

“…85 Atrial tissue changes which accompany AF include cardiomyocyte hypertrophy, interstitial fibrosis, and molecular changes of oxidative stress. 86 The degree of atrial fibrosis as assessed by late gadolinium enhancement on MRI has been associated with the presence of LAA thrombi and spontaneous contrast, 87 as has left atrial dysfunction identified by strain imaging which identifies abnormalities in myocardial deformation. 88,89 Bipolar voltage mapping of the left atrium in AF has correlated the extent of myopathic low voltage electrograms (≤0.5 mV) with reduced LAA emptying velocity.…”