Clinical subtypes of lone atrial fibrillation.

AIMS

In the face of increasing evidence of underlying genetic heterogeneity for lone atrial fibrillation (LAF), we undertook a clinical analysis of subjects to identify the phenotypic subsets of this arrhythmia.

METHODS AND RESULTS

We evaluated serial patients who presented with LAF between July 5, 2001 and December 19, 2003. Subjects underwent a standardized interview to elicit a detailed medical history, prior therapies, and precipitants of atrial fibrillation. The results of a physical exam, electrocardiogram and echocardiogram were reviewed. One hundred and eighty subjects with a mean age of 45 years (15-67 years) at the time of diagnosis were enrolled. The majority of patients originally presented with paroxysmal fibrillation (94%), and 7.8% progressed to permanent AF. Reported triggers for AF included sleeping (44%), exercise (36%), alcohol use (36%), and eating (34%). Women with LAF had distinct symptoms, triggers for episodic AF, and over one-fourth had an underlying rheumatologic condition. Several subsets of AF including familial AF (39%), exercise-induced AF (32%), and conduction system disease requiring pacemaker implantation (7%), were identified.

CONCLUSIONS

Family history, exercise as a trigger of AF, and a history of a pacemaker identified subtypes of LAF.