More atrial than ventricular signals indicates that the rhythm is originating in the atrium. To determine the mechanism of the atrial arrhythmia we will evaluate the rate, regularity, and appearance of the AEG signals. In these patients, especially if the ventricular rate is not substantially elevated, one must consider atrioventricular nodal conduction disease or injury causing some degree of heart block. Pre-excited atrial fibrillation was not included in this algorithm. However, if atrial fibrillation is present with a variable QRS suggestive of pre-excitation, this should be considered.
