Study of P wave morphology in lead V1 during supraventricular tachycardia for localizing the reentrant circuit
1991; Elsevier BV; Volume: 121; Issue: 6 Linguagem: Inglês
10.1016/0002-8703(91)90017-c
ISSN1097-6744
Autores Tópico(s)Cardiac electrophysiology and arrhythmias
ResumoParoxysmal supraventricular tachycardia (SVT) is a benign form of tachycardia that generally does not require costly evaluation. The purpose of this study was to describe a new sign permitting delineation of the mechanism of SVT by analysis of the P wave in lead V1 and the left atrial electrogram, which may be registered by the esophageal electrode. Among 146 patients with SVT, 72 had a ventriculoatrial interval >70 msec. The P wave in lead V1 during SVT was discernible in 69 of them. The precession of the left atrial electrogram on the P wave in lead V1 was always associated with reentry through a left lateral (n = 37) or posteroseptal (n = 4) accessory atrioventricular (AV) connection. When the P wave in lead V1 preceded or occurred simultaneously with the left atrial electrogram, reentry was through either the AV node or a right-sided accessory AV connection. On the other hand, although the P wave in lead V1 was more frequently negative in reentry through a right-sided connection and positive in reentry through a left-sided connection, the polarity was not specific enough to identify the reentry. The precession of the left atrial electrogram recorded by the esophageal electrode on the P wave in lead V1 during SVT was a specific criterion of reentry through a left accessory AV connection, and this technique could be useful for preliminary localization of the accessory connection before electrophysiologic study.
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