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Updated: May 25, 2026

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
08:13

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

Published on: February 16, 2016

Tachycardic vs. pharmacologic stress myocardial perfusion imaging: differential implications in multi-vessel ischemia

Thanh H Nguyen, John D Horowitz, Steven A Unger

    American Journal of Cardiovascular Disease
    |January 19, 2012
    PubMed

    Insights

    Dipyridamole and pacing are comparable for detecting myocardial ischemia in patients unable to exercise. Dipyridamole may accentuate ischemia in primary zones, a factor to consider during myocardial perfusion imaging interpretation.

    Area of Science:

    • Cardiology
    • Nuclear Medicine
    • Diagnostic Imaging

    Background:

    • Patients unable to exercise require alternative methods for inducing reversible myocardial ischemia.
    • Pacing and dipyridamole are established methods for inducing ischemia but have different mechanisms.
    • No direct comparison of dipyridamole and pacing for myocardial perfusion imaging (MPI) has been reported.

    Purpose of the Study:

    • To compare dipyridamole and pacing for detecting, localizing, and quantifying myocardial ischemia.
    • To evaluate the concordance and differences in ischemia assessment between the two methods.

    Main Methods:

    • A randomized, paired comparison of dipyridamole and pacing MPI was conducted.
    • The study included 28 patients unable to undergo exercise stress imaging.
    • Detection, localization, and quantification of ischemia were compared between the two techniques.

    Main Results:

    • Reversible myocardial ischemia was detected in 21 patients, with high concordance in localization (p < 0.0001).
    • A good correlation (r = 0.74, p < 0.0001) was observed in the total size of ischemic zones.
    • Dipyridamole tended to show a greater magnitude of ischemia, particularly in primary ischemic zones of patients with multi-vessel disease (p = 0.046).

    Conclusions:

    • Dipyridamole and pacing yield similar results for ischemia detection, localization, and severity.
    • Dipyridamole accentuates ischemia in primary zones, consistent with coronary "steal" phenomenon.
    • Consideration of dipyridamole's mechanism is important for interpreting MPI scan results.
    Abstract

    Keywords:
    Dipyridamolecoronary “steal"myocardial perfusion imagingpacing

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