Reproducibility of arrhythmia induction with intracardiac electrophysiologic testing: Patients with clinical sustained ventricular tachyarrhythmias

Abstract

In order to characterize the day to day reproducibility of arrhythmias provoked during electrophysiologic stimulation, 114 patients with documented sustained clinical ventricular tachyarrhythmias were studied. Two baseline electrophysiologic tests were performed in the drug-free state and within 6 to 24 hours of one another. There was a significant increment (p less than or equal to 0.02) in the induction of sustained ventricular tachyarrhythmias as the number of programmed extrastimuli increased from one (10% induction) to four (64% induction). Provoked arrhythmias were observed to be more frequently nonreproducible (as reflected in a major change in rate or duration, or both, of an induced ventricular arrhythmia between baseline tests) as the number of extrastimuli increased from one (7%) to four (27%). Nonreproducibility with three and four extrastimuli was not significantly greater than when two extrastimuli were utilized. Electrophysiology-directed drug trials should be interpreted in light of this observed variability in induced arrhythmias.

Electrophysiology of Ventricular Tachycardia:

“…These investigators demonstrated that induction of monomorphic VT was a reproducible and specific response to PES, whereas the initiation of ventricular fibrillation (VF) and polymorphic VT was nonspecific. These conclusions were supported by subsequent studies 12–21 . All of these studies suggested that the optimal method to achieve maximum sensitivity and specificity for VT induction using PES was a protocol incorporating three extrastimuli from the RV apex and RV outflow tract (RVOT), during at least two drive cycle lengths (600 and 400 msec).…”

Clinical Significance and Contributing Factors of Long‐Term Variability in Induced Ventricular Tachyarrhythmias

“…In our study, 58% of patients exhibited long‐term variability in the severity of induced arrhythmias. In the studies evaluating the reproducibility of arrhythmia induction by programmed stimulation, immediate reproducibility assessed by the repeated induction protocol was high (91%–100%), 10–12 whereas day‐to‐day reproducibility varied widely among the studies reported 13–15 . In terms of long‐term reproducibility, several reports compared the results of EPS performed with an interval of more than several months, 16–18 and the degree of reproducibility was similar among the studies (47%–60%).…”

“…In the studies evaluating the reproducibility of arrhythmia induction by programmed stimulation, immediate reproducibility assessed by the repeated induction protocol was high (91%-100%), [10][11][12] whereas day-to-day reproducibility varied widely among the studies reported. [13][14][15] In terms of long-term reproducibility, several reports compared the results of EPS performed with an interval of more than several months, [16][17][18] and the degree of reproducibility was similar among the studies (47%-60%). In the present study, the proportion of patients in whom the severity of induced arrhythmia was always consistent over the series of EPSs was relatively low.…”

“…Reproducibility of the induction of ventricular arrhythmias has been reported for both short-term (immediate or days) and long-term studies (months or years), [10][11][12][13][14][15][16][17][18] with long-term reproducibility reported in only 47% to 60% of patients. [16][17][18] At present, the contributing factors and clinical significance of long-term variability in induced arrhythmias, especially the relationship between such variability and manifestation of spontaneous arrhythmias, has not been fully investigated.…”

Ventricular Arrhythmias Induced by Programmed Ventricular Stimulation After Uncomplicated Myocardial Infarction

“…The objective of this study was twofold: (1) to assess the inducibility of ventricular arrhythmias in patients without clinically manifest complex ventricular arrhythmias following first infarction; (2) to correlate inducible arrhythmias with syncope and sudden death.…”