Infiltrated atrial fat characterizes underlying atrial fibrillation substrate in patients at risk as defined by the ARIC atrial fibrillation risk score

Abstract

Background It is known that expanded epicardial fat is associated with atrial fibrillation (AF). However, infiltrated intraatrial fat has not been previously quantified in individuals at risk as determined by the ARIC AF risk score. Methods Patients in sinus rhythm (N=90, age 57±10y; 55 men [63.2%]), in 3 groups at risk of AF as determined by the ARIC AF risk score [low (≤11 points; n=15), moderate (12–18 points; n=40), high (≥19 points; n=23) risk of AF], and paroxysmal AF (n=12) underwent cardiac magnetic resonance study. Intraatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. OsiriX DICOM viewer (Geneva, Switzerland) was used to quantify the intraatrial fat area. Width of the cephalad portion of the interatrial septum was measured at the level of the fossa ovalis. Results Intraatrial fat monotonically increased with growing AF risk in study groups (low AF risk 16±4 vs. moderate AF risk 32±18 vs. high AF risk 81±83 mm2; ANOVA P=0.012). Log-transformed intraatrial fat predicted ARIC AF risk score in multivariate ordered probit regression after adjustment for sex, race, left and right atrial area indices, and body mass index (β-coefficient 0.50 [95%CI 0.03–0.97]; P=0.037), whereas epicardial fat did not. Interatrial septum width showed similar association (3.0±1.4 vs. 5.0±1.8 vs. 7.1±2.7 mm; ANOVA P<0.001; adjusted β-coefficient 2.80 [95%CI 1.19–4.41]; P=0.001). Conclusions Infiltrated intraatrial fat characterizes evolving substrate in individuals at risk of AF.

Electrocardiographic Deep Terminal Negativity of the P Wave in V 1 and Risk of Sudden Cardiac Death: The Atherosclerosis Risk in Communities (ARIC) Study

“…9 Posteriorly directed LA depolarization vector is primarily responsible for the appearance of P wave terminal negative deflection in V 1 . We speculate that intraatrial fat infiltration 40–41 and gradual development of atrial fibrosis could lead to the interruption of interatrial conduction over tiny (and therefore more susceptible) posterior interatrial connections, resulting in predominant conduction via the Bachmann's bundle, associated with the anterior‐to‐posterior direction of left atrial activation. Pulmonary vein isolation could modify P wave morphology in V 1.…”

Associations of electrocardiographic P-wave characteristics with left atrial function, and diffuse left ventricular fibrosis defined by cardiac magnetic resonance: The PRIMERI Study

“…The PRIMERI study is an ongoing prospective observational cohort study 19–21 of the Johns Hopkins Hospital patients with ECG signs of structural heart disease. The study protocol was approved by the Johns Hopkins Hospital Institutional Review Board.…”

“…In the Personalized Risk Identification and Management for Arrhythmias and Heart Failure by ECG and CMR (PRIMERI) study 19–21 , both ECG and CMR were acquired within the same day. We hypothesized that LV interstitial fibrosis is associated with altered atrial electrophysiology and function in PRIMERI study participants.…”

Comparison of cardiac computed tomography versus cardiac magnetic resonance for characterization of left atrium anatomy before radiofrequency catheter ablation of atrial fibrillation

“…This process consists in four steps: 1) CCT or CMR scan is performed and dataset are imported in dedicated workstation to be segmented; 2) LA is electro-anatomically reconstructed during the procedure; 3) merge phase in which the two maps of LA are superimposed by landmark or surface registration to produce a hybrid map; 4) ablator catheter navigation into electro-anatomic map reached. The integration of a 3D LA imaging by CCT or CMR with its electrical map into hybrid-fused image has been validated in several studies [11][12][13][14][15][16][17][18][19][39][40][41]. Kistler et al [11] showed a reduced fluoroscopy time, arrhythmia recurrence and need for repeat procedure by CCT-guided RFCA.…”

“…However, because of the complexity and variability of left atrium (LA) and PV anatomy, RFCA remains technically very challenging even for experienced electro-physiologists. Due to these limitations, the outcome of RFCA has been improved by the pivotal role of multimodality cardiovascular imaging such as cardiac computed tomography (CCT) or cardiac magnetic resonance (CMR) for the characterization LA anatomy before RFCA [11][12][13][14][15][16][17][18][19]. However, no comparative data between CCT and CMR have been described regarding the impact of different imaging modalities on procedural and clinical outcomes.…”