Demographic and Clinical Characteristics to Predict Paroxysmal Atrial Fibrillation: Insights from an Implantable Loop Recorder Population.

BACKGROUND: There is growing interest in detecting paroxysmal atrial fibrillation (PAF) to identify patients at high risk of thromboembolic stroke. The implantable loop recorder (ILR) is emerging as a powerful new tool in the diagnosis of PAF. Widespread implantation has significant cost implications and their use must be targeted at those patients at most risk.

METHODS: We retrospectively studied a population of 200 adult patients who underwent ILR implantation for the investigation of syncope or palpitations. Clinical data, baseline electrocardiogram (ECG) characteristics, and echocardiographic data were collected. All ECGs and electrograms (EGMs) were scrutinized by two blinded investigators. PAF incidence was defined as episodes lasting >30 seconds on EGMs recorded in ILR memory.

RESULTS: Our ILR population consists of 200 patients, 111 (56%) male, with a mean age of 61.4 years (range 19-95). PAF was detected in 42 patients. The following factors were significant predictors of PAF by multivariate logistic regression analysis: cigarette smoking (odds ratio [OR] = 3.73, 95% confidence interval [CI] = 1.40-10.24, P = 0.009) and incomplete right bundle branch block (IRBBB; OR = 9.04, 95% CI = 2.51-34.64, P = 0.00088). Significant differences included incidence of IRBBB (P = 0.012), cigarette smoking (P = 0.026), hypercholesterolemia (P = 0.015), age (P = 0.002), estimated glomerular filtration rate (P = 0.031), left atrial volume (P = 0.019), and PR interval (P = 0.031). The PAF group had significantly higher CHA2 DS2 -VASc scores (P = 0.01).

CONCLUSIONS: Our study reports predictive factors for PAF in an ILR population. We suggest that cigarette smoking and IRBBB are independently associated with paroxysmal AF in patients presenting with palpitations or syncope.