[Paroxysmal loss of consciousness. Comparison of electrophysiologic and holter monitoring results].

Holter monitoring is one of the most commonly done test in the evaluation of patients with syncope. As Holter monitoring may miss an arrhythmia or document an asymptomatic arrhythmia invasive electrophysiologic testing has been applied in patients with syncope. The purpose of this study was to compare Holter monitoring and electrophysiologic tests in patients with syncope of unexplained origin. The group consisted of 100 patients with syncope of unknown origin. Coronary artery disease was present in 43 patients, other heart disease in 19 patients and no structural heart disease was found in 38 patients. Electrophysiological testing consisted of (1) recording of His bundle electrogram, (2) atrial stimulation, (3) ventricular stimulation with 1.2 and 3 extrastimuli at three basic cycle lengths. The results of Holter monitoring were classified by severity of abnormalities into three classes: I--normal study; II--moderate abnormalities; III--severe abnormalities: sinus rhythm with pauses longer than 3 s, Mobitz II or complete atrio-ventricular block, supraventricular arrhythmia faster than 180 bpm, sustained ventricular tachycardia. Abnormalities of electrophysiologic testing were grouped as: I normal study; II--moderate abnormalities; III--severe abnormalities: sinus nodal recovery time more than 3 s, HV interval longer than 100 ms, supraventricular arrhythmia faster than 200 bpm, sustained ventricular tachycardia. Class III abnormalities were documented in 17 patients on Holter monitoring and in 20 patients by electrophysiologic testing. Compatibility between class III abnormalities in Holter monitoring and electrophysiological testing was noted in 4 patients, discordance of class III results in 33 patients.(ABSTRACT TRUNCATED AT 250 WORDS)