Atrial fibrillation detection with implantable loop recorders in a community-based cardiology practice: Limited...

Paroxysmal atrial fibrillation is a major contributor to cryptogenic stroke and may be underdetected with conventional rhythm monitoring. Transthoracic echocardiographic abnormalities have been proposed to guide implantable loop recorder (ILR) selection, although their predictive value remains uncertain.

To evaluate the incidence of atrial fibrillation (AF) detection during ILR monitoring and examine associations with echocardiographic findings in an outpatient cardiology population.

A retrospective cohort study of 133 patients undergoing ILR implantation was conducted. Echocardiographic parameters, including left atrial size, left ventricular ejection fraction, diastolic dysfunction, filling pressures, and valvular disease, were analyzed for associations with AF detection. Multivariable logistic regression adjusted for age and monitoring duration.

Atrial fibrillation was detected in a substantial proportion of patients. Implantable loop recorder implantation was most commonly performed for AF surveillance and cerebrovascular indications. Diastolic dysfunction demonstrated a statistically significant inverse association with AF detection, with AF occurring more frequently among patients without documented diastolic dysfunction. Other structural and functional echocardiographic parameters were not associated with AF detection. Age and monitoring duration were not independently predictive. Among patients implanted for cerebrovascular indications, AF detection remained common; however, no clinical or echocardiographic variables independently predicted detection.

Conventional echocardiographic parameters demonstrated limited discriminatory value for predicting AF during prolonged ILR monitoring.

Implantable loop recorder selection should be guided by comprehensive clinical assessment rather than echocardiographic findings alone to optimize AF detection and secondary stroke prevention.