Left Atrial Enlargement as a Predictor of Silent Paroxysmal Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia and it may be symptomatic (manifest), or asymptomatic (silent). Silent AF is much more common than manifest AF. Both paroxysmal (PAF) and persistent AF confer a risk of embolic stroke. Increased left atrial (LA) size is associated with an increased prevalence of non-valvular AF and could be a predictor of stroke. Relationship between LA size and asymptomatic attacks of PAF in hypertensive patients. Sixty hypertensive patients following at the cardiac outpatient clinic having controlled hypertension (HTN) underwent ambulatory Holter monitoring (HM) for detection of silent PAF and measurement of left atrium antero-posterior diameter (LAAPd) using M-mode echocardiogram. Patients were classified into two groups according the LAAPd: group I; twenty-six patients and having increased LAAPd and group II; thiry-four having normal LAAPd. Patients in both groups have comparable demographic variables, cardiovascular (CV) risk factors, controlled BP; antihypertensive drugs used to control BP, and left ventricular size and function. Upon HM, 11 (18%) patients found to silent PAF, 8 (30.7%) in group I and 3 in group II (8.8%). Thus hypertensive patients having increased LAAPd have significantly more attacks of silent PAF than hypertensive patients with normal LAAPd (P = 0.043). Increased LAAPd can be used in selecting hypertensive patients for HM to identify patients having silent PAF and thus at risk for embolic stroke.