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Comparison of microvolt T-wave alternans measurements using atrial pacing compared to atropine administration

Stefan Weber1, Jörg O Schwab

  • 1Department of Internal Medicine-Cardiology, University of Regensburg, Regensburg, Germany. stefan.weber@klinik.uni-regensburg.de

Pacing and Clinical Electrophysiology : PACE
|December 12, 2007
PubMed
Abstract

Insights

Intravenous atropine safely increases heart rate for microvolt T-wave alternans (MTWA) testing in patients unable to exercise. This non-invasive method provides reliable results comparable to right atrial pacing for predicting ventricular arrhythmias.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Devices

Background:

  • Microvolt T-wave alternans (MTWA) is a marker for malignant ventricular arrhythmias in patients with structural heart disease.
  • MTWA is heart rate-dependent, but exercise limitations hinder its assessment in some patients.
  • Alternative methods to increase heart rate for MTWA testing are needed.

Purpose of the Study:

  • To evaluate the feasibility of noninvasive MTWA measurement using intravenous atropine to increase heart rate.
  • To compare atropine-induced heart rate elevation with right atrial (RA) pacing for MTWA assessment.
  • To determine the safety and reliability of atropine for MTWA testing.

Main Methods:

  • Investigated MTWA measurement using intravenous atropine in 27 patients.
  • Compared atropine results with MTWA measurements obtained via RA pacing during electrophysiologic (EP) study.
  • Performed 18-month follow-up to determine arrhythmia event rates.

Main Results:

  • Atropine successfully increased heart rate in 82% of patients.
  • MTWA assessment showed concordant results between atropine and RA pacing in 96% of patients.
  • Positive MTWA tests correlated with documented ventricular arrhythmias during follow-up; no events occurred in the MTWA-negative group.

Conclusions:

  • Intravenous atropine is a safe, non-invasive, and reliable method for MTWA assessment when target heart rates are achieved.
  • Atropine-induced MTWA results are comparable to those from RA pacing.
  • Pharmacological increase of heart rate with atropine does not lead to false-positive MTWA results.

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