INTEREPISODE COMPARISON OF PAROXYSMAL ATRIAL-FIBRILLATION OCCURRENCES

Some evidence suggests that in those who suffer from paroxysmal atrial fibrillation, the AF is triggered by reproducible phenomena such as b radycardia, tachycardia, or ectopic activity. Seven patients with at l east 5 episodes of paroxysmal AF captured on Holter tape were identifi ed from a database of paroxysmal AF Holter recordings. Each episode wa s required to last at least 30 seconds, and to be preceded by at least 2 minutes of noise free sinus rhythm. The episodes were characterised by their duration, time of onset and fluctuations in heart rate and e ctopic beat frequency before onset. All episodes were also printed as tachograms and visually inspected. Of the seven patients, 5 were male, 5 were on no medication at the time of recording and the mean age was 56 yr. There were a total of 109 episodes. 3 patients had predominant ly nocturnal. AF, and one mostly daytime AF. In all patients, daytime AF tended to last longer. Heart rate at AF onset did not differ from 2 4 hour mean, and most patients demonstrated a trend towards normalisin g heart rate over the 2 min prior to AF onset (i.e. acceleration of br adycardia and vice versa). Atrial ectopics increased prior to AF, but substantial inter-episode variation was evident. Thus, in patients who have frequent episodes of PAF, individual patterns of heart rhythm be haviour are seen, but inter-episode variation always exists.