An analysis of the P wave in patients with transient benign atrial fibrillation.

TRIAL FIBRILLATION OCCURRING IN THE absence of any detectable heart disease has been termed " benign atrial fibrillation, " " isolated atrial fibrillation, " " idiopathic atrial fibrillation " and " lone atrial fibrilla-tion.' ' It has been recognized for a number of 'ears and several reports are available concerning the subject.. Exactly what defect exists that predisposes apparently otherwise completely normal individuals to bouts of atrial fibrillation is unclean. The absence of an anatomic abnormality is implied by the fact that " heart disease " has been cx-cluded. Careful reflection would indicate, however, that any altered function must certainly have as its basis some altered structure, although this may only be at a molecular level. The real problem then lies at the level of observation chosen to evaluate anatomic changes. When " heart disease " is excluded on a clinical basis, it is clear that this is done at a relatively gross level. Nevertheless, when investigated with the tools of diagnosis currently available, there exists a group of patients in whom atnial fibrillation occurs, and in whom no other evidence for cardiac abnormality can be obtained. These atria that fibrillate certainly cannot be considered completely normal ; however, a definition of any underlying abnormality has not yet been clearly delineated. Evaluation of the amplitude, duration and configuration of the electnocardio-graphically recorded waves of atrial activity *From the Department of Medicine and Cardio-The opinions or assertions contained herein are those of the authors and are not to be construed as official or reflecting the views of the Navy Department or of the Naval Service at large. has been utilized for many years in attempts to indicate abnormalities of either the right or the left atrium. The electrocardiographic patterns of " P mitrale " and " P pulmonale " are well known. In addition to the standard measurements, other indices for P wave evaluation have been proposed. " 5 Because of a rather lange experience at this institution with patients with transient benign atrial fibrillation it was decided to study carefully the P waves of these mdi-viduals during periods of normal sinus rhythm to determine if differences existed when compared with normal controls. METHOD The control group consisted of 36 age and sex matched normal subjects selected from various surgical sub-specialty wards. The electrocardiograms in these individuals were reviewed only after actual or potential heart disease (or an etiologic factor predisposing …